bionic (5) collectd.conf.5.gz

Provided by: collectd-core_5.7.2-2ubuntu1.2_amd64 bug

NAME

       collectd.conf - Configuration for the system statistics collection daemon collectd

SYNOPSIS

         BaseDir "/var/lib/collectd"
         PIDFile "/run/collectd.pid"
         Interval 10.0

         LoadPlugin cpu
         LoadPlugin load

         <LoadPlugin df>
           Interval 3600
         </LoadPlugin>
         <Plugin df>
           ValuesPercentage true
         </Plugin>

         LoadPlugin ping
         <Plugin ping>
           Host "example.org"
           Host "provider.net"
         </Plugin>

DESCRIPTION

       This config file controls how the system statistics collection daemon collectd behaves. The most
       significant option is LoadPlugin, which controls which plugins to load. These plugins ultimately define
       collectd's behavior. If the AutoLoadPlugin option has been enabled, the explicit LoadPlugin lines may be
       omitted for all plugins with a configuration block, i.e. a "<Plugin ...>" block.

       The syntax of this config file is similar to the config file of the famous Apache webserver. Each line
       contains either an option (a key and a list of one or more values) or a section-start or -end. Empty
       lines and everything after a non-quoted hash-symbol ("#") are ignored. Keys are unquoted strings,
       consisting only of alphanumeric characters and the underscore ("_") character. Keys are handled case
       insensitive by collectd itself and all plugins included with it. Values can either be an unquoted string,
       a quoted string (enclosed in double-quotes) a number or a boolean expression. Unquoted strings consist of
       only alphanumeric characters and underscores ("_") and do not need to be quoted. Quoted strings are
       enclosed in double quotes ("""). You can use the backslash character ("\") to include double quotes as
       part of the string. Numbers can be specified in decimal and floating point format (using a dot "." as
       decimal separator), hexadecimal when using the "0x" prefix and octal with a leading zero (0).  Boolean
       values are either true or false.

       Lines may be wrapped by using "\" as the last character before the newline.  This allows long lines to be
       split into multiple lines. Quoted strings may be wrapped as well. However, those are treated special in
       that whitespace at the beginning of the following lines will be ignored, which allows for nicely
       indenting the wrapped lines.

       The configuration is read and processed in order, i.e. from top to bottom. So the plugins are loaded in
       the order listed in this config file. It is a good idea to load any logging plugins first in order to
       catch messages from plugins during configuration. Also, unless AutoLoadPlugin is enabled, the LoadPlugin
       option must occur before the appropriate "<Plugin ...>" block.

GLOBAL OPTIONS

       BaseDir Directory
           Sets the base directory. This is the directory beneath which all RRD-files are created. Possibly more
           subdirectories are created. This is also the working directory for the daemon.

       LoadPlugin Plugin
           Loads the plugin Plugin. This is required to load plugins, unless the AutoLoadPlugin option is
           enabled (see below). Without any loaded plugins, collectd will be mostly useless.

           Only the first LoadPlugin statement or block for a given plugin name has any effect. This is useful
           when you want to split up the configuration into smaller files and want each file to be "self
           contained", i.e. it contains a Plugin block and the appropriate LoadPlugin statement. The downside is
           that if you have multiple conflicting LoadPlugin blocks, e.g. when they specify different intervals,
           only one of them (the first one encountered) will take effect and all others will be silently
           ignored.

           LoadPlugin may either be a simple configuration statement or a block with additional options,
           affecting the behavior of LoadPlugin. A simple statement looks like this:

            LoadPlugin "cpu"

           Options inside a LoadPlugin block can override default settings and influence the way plugins are
           loaded, e.g.:

            <LoadPlugin perl>
              Interval 60
            </LoadPlugin>

           The following options are valid inside LoadPlugin blocks:

           Globals true|false
               If enabled, collectd will export all global symbols of the plugin (and of all libraries loaded as
               dependencies of the plugin) and, thus, makes those symbols available for resolving unresolved
               symbols in subsequently loaded plugins if that is supported by your system.

               This is useful (or possibly even required), e.g., when loading a plugin that embeds some
               scripting language into the daemon (e.g. the Perl and Python plugins). Scripting languages
               usually provide means to load extensions written in C. Those extensions require symbols provided
               by the interpreter, which is loaded as a dependency of the respective collectd plugin.  See the
               documentation of those plugins (e.g., collectd-perl(5) or collectd-python(5)) for details.

               By default, this is disabled. As a special exception, if the plugin name is either "perl" or
               "python", the default is changed to enabled in order to keep the average user from ever having to
               deal with this low level linking stuff.

           Interval Seconds
               Sets a plugin-specific interval for collecting metrics. This overrides the global Interval
               setting. If a plugin provides its own support for specifying an interval, that setting will take
               precedence.

           FlushInterval Seconds
               Specifies the interval, in seconds, to call the flush callback if it's defined in this plugin. By
               default, this is disabled.

           FlushTimeout Seconds
               Specifies the value of the timeout argument of the flush callback.

       AutoLoadPlugin false|true
           When set to false (the default), each plugin needs to be loaded explicitly, using the LoadPlugin
           statement documented above. If a <Plugin ...> block is encountered and no configuration handling
           callback for this plugin has been registered, a warning is logged and the block is ignored.

           When set to true, explicit LoadPlugin statements are not required. Each <Plugin ...> block acts as if
           it was immediately preceded by a LoadPlugin statement. LoadPlugin statements are still required for
           plugins that don't provide any configuration, e.g. the Load plugin.

       CollectInternalStats false|true
           When set to true, various statistics about the collectd daemon will be collected, with "collectd" as
           the plugin name. Defaults to false.

           The following metrics are reported:

           "collectd-write_queue/queue_length"
               The number of metrics currently in the write queue. You can limit the queue length with the
               WriteQueueLimitLow and WriteQueueLimitHigh options.

           "collectd-write_queue/derive-dropped"
               The number of metrics dropped due to a queue length limitation.  If this value is non-zero, your
               system can't handle all incoming metrics and protects itself against overload by dropping
               metrics.

           "collectd-cache/cache_size"
               The number of elements in the metric cache (the cache you can interact with using
               collectd-unixsock(5)).

       Include Path [pattern]
           If Path points to a file, includes that file. If Path points to a directory, recursively includes all
           files within that directory and its subdirectories. If the "wordexp" function is available on your
           system, shell-like wildcards are expanded before files are included. This means you can use
           statements like the following:

             Include "/etc/collectd.d/*.conf"

           Starting with version 5.3, this may also be a block in which further options affecting the behavior
           of Include may be specified. The following option is currently allowed:

             <Include "/etc/collectd.d">
               Filter "*.conf"
             </Include>

           Filter pattern
               If the "fnmatch" function is available on your system, a shell-like wildcard pattern may be
               specified to filter which files to include. This may be used in combination with recursively
               including a directory to easily be able to arbitrarily mix configuration files and other
               documents (e.g. README files).  The given example is similar to the first example above but
               includes all files matching "*.conf" in any subdirectory of "/etc/collectd.d".

           If more than one file is included by a single Include option, the files will be included in
           lexicographical order (as defined by the "strcmp" function). Thus, you can e. g. use numbered
           prefixes to specify the order in which the files are loaded.

           To prevent loops and shooting yourself in the foot in interesting ways the nesting is limited to a
           depth of 8 levels, which should be sufficient for most uses. Since symlinks are followed it is still
           possible to crash the daemon by looping symlinks. In our opinion significant stupidity should result
           in an appropriate amount of pain.

           It is no problem to have a block like "<Plugin foo>" in more than one file, but you cannot include
           files from within blocks.

       PIDFile File
           Sets where to write the PID file to. This file is overwritten when it exists and deleted when the
           program is stopped. Some init-scripts might override this setting using the -P command-line option.

       PluginDir Directory
           Path to the plugins (shared objects) of collectd.

       TypesDB File [File ...]
           Set one or more files that contain the data-set descriptions. See types.db(5) for a description of
           the format of this file.

           If this option is not specified, a default file is read. If you need to define custom types in
           addition to the types defined in the default file, you need to explicitly load both. In other words,
           if the TypesDB option is encountered the default behavior is disabled and if you need the default
           types you have to also explicitly load them.

       Interval Seconds
           Configures the interval in which to query the read plugins. Obviously smaller values lead to a higher
           system load produced by collectd, while higher values lead to more coarse statistics.

           Warning: You should set this once and then never touch it again. If you do, you will have to delete
           all your RRD files or know some serious RRDtool magic! (Assuming you're using the RRDtool or
           RRDCacheD plugin.)

       MaxReadInterval Seconds
           A read plugin doubles the interval between queries after each failed attempt to get data.

           This options limits the maximum value of the interval. The default value is 86400.

       Timeout Iterations
           Consider a value list "missing" when no update has been read or received for Iterations iterations.
           By default, collectd considers a value list missing when no update has been received for twice the
           update interval. Since this setting uses iterations, the maximum allowed time without update depends
           on the Interval information contained in each value list. This is used in the Threshold configuration
           to dispatch notifications about missing values, see collectd-threshold(5) for details.

       ReadThreads Num
           Number of threads to start for reading plugins. The default value is 5, but you may want to increase
           this if you have more than five plugins that take a long time to read. Mostly those are plugins that
           do network-IO. Setting this to a value higher than the number of registered read callbacks is not
           recommended.

       WriteThreads Num
           Number of threads to start for dispatching value lists to write plugins. The default value is 5, but
           you may want to increase this if you have more than five plugins that may take relatively long to
           write to.

       WriteQueueLimitHigh HighNum
       WriteQueueLimitLow LowNum
           Metrics are read by the read threads and then put into a queue to be handled by the write threads. If
           one of the write plugins is slow (e.g. network timeouts, I/O saturation of the disk) this queue will
           grow. In order to avoid running into memory issues in such a case, you can limit the size of this
           queue.

           By default, there is no limit and memory may grow indefinitely. This is most likely not an issue for
           clients, i.e. instances that only handle the local metrics. For servers it is recommended to set this
           to a non-zero value, though.

           You can set the limits using WriteQueueLimitHigh and WriteQueueLimitLow.  Each of them takes a
           numerical argument which is the number of metrics in the queue. If there are HighNum metrics in the
           queue, any new metrics will be dropped. If there are less than LowNum metrics in the queue, all new
           metrics will be enqueued. If the number of metrics currently in the queue is between LowNum and
           HighNum, the metric is dropped with a probability that is proportional to the number of metrics in
           the queue (i.e. it increases linearly until it reaches 100%.)

           If WriteQueueLimitHigh is set to non-zero and WriteQueueLimitLow is unset, the latter will default to
           half of WriteQueueLimitHigh.

           If you do not want to randomly drop values when the queue size is between LowNum and HighNum, set
           WriteQueueLimitHigh and WriteQueueLimitLow to the same value.

           Enabling the CollectInternalStats option is of great help to figure out the values to set
           WriteQueueLimitHigh and WriteQueueLimitLow to.

       Hostname Name
           Sets the hostname that identifies a host. If you omit this setting, the hostname will be determined
           using the gethostname(2) system call.

       FQDNLookup true|false
           If Hostname is determined automatically this setting controls whether or not the daemon should try to
           figure out the "fully qualified domain name", FQDN.  This is done using a lookup of the name returned
           by "gethostname". This option is enabled by default.

       PreCacheChain ChainName
       PostCacheChain ChainName
           Configure the name of the "pre-cache chain" and the "post-cache chain". Please see "FILTER
           CONFIGURATION" below on information on chains and how these setting change the daemon's behavior.

PLUGIN OPTIONS

       Some plugins may register own options. These options must be enclosed in a "Plugin"-Section. Which
       options exist depends on the plugin used. Some plugins require external configuration, too. The "apache
       plugin", for example, required "mod_status" to be configured in the webserver you're going to collect
       data from. These plugins are listed below as well, even if they don't require any configuration within
       collectd's configuration file.

       A list of all plugins and a short summary for each plugin can be found in the README file shipped with
       the sourcecode and hopefully binary packets as well.

   Plugin "aggregation"
       The Aggregation plugin makes it possible to aggregate several values into one using aggregation functions
       such as sum, average, min and max.  This can be put to a wide variety of uses, e.g. average and total CPU
       statistics for your entire fleet.

       The grouping is powerful but, as with many powerful tools, may be a bit difficult to wrap your head
       around. The grouping will therefore be demonstrated using an example: The average and sum of the CPU
       usage across all CPUs of each host is to be calculated.

       To select all the affected values for our example, set "Plugin cpu" and "Type cpu". The other values are
       left unspecified, meaning "all values". The Host, Plugin, PluginInstance, Type and TypeInstance options
       work as if they were specified in the "WHERE" clause of an "SELECT" SQL statement.

         Plugin "cpu"
         Type "cpu"

       Although the Host, PluginInstance (CPU number, i.e. 0, 1, 2, ...)  and TypeInstance (idle, user, system,
       ...) fields are left unspecified in the example, the intention is to have a new value for each host /
       type instance pair. This is achieved by "grouping" the values using the "GroupBy" option.  It can be
       specified multiple times to group by more than one field.

         GroupBy "Host"
         GroupBy "TypeInstance"

       We do neither specify nor group by plugin instance (the CPU number), so all metrics that differ in the
       CPU number only will be aggregated. Each aggregation needs at least one such field, otherwise no
       aggregation would take place.

       The full example configuration looks like this:

        <Plugin "aggregation">
          <Aggregation>
            Plugin "cpu"
            Type "cpu"

            GroupBy "Host"
            GroupBy "TypeInstance"

            CalculateSum true
            CalculateAverage true
          </Aggregation>
        </Plugin>

       There are a couple of limitations you should be aware of:

       •   The Type cannot be left unspecified, because it is not reasonable to add apples to oranges. Also, the
           internal lookup structure won't work if you try to group by type.

       •   There must be at least one unspecified, ungrouped field. Otherwise nothing will be aggregated.

       As you can see in the example above, each aggregation has its own Aggregation block. You can have
       multiple aggregation blocks and aggregation blocks may match the same values, i.e. one value list can
       update multiple aggregations. The following options are valid inside Aggregation blocks:

       Host Host
       Plugin Plugin
       PluginInstance PluginInstance
       Type Type
       TypeInstance TypeInstance
           Selects the value lists to be added to this aggregation. Type must be a valid data set name, see
           types.db(5) for details.

           If the string starts with and ends with a slash ("/"), the string is interpreted as a regular
           expression. The regex flavor used are POSIX extended regular expressions as described in regex(7).
           Example usage:

            Host "/^db[0-9]\\.example\\.com$/"

       GroupBy Host|Plugin|PluginInstance|TypeInstance
           Group valued by the specified field. The GroupBy option may be repeated to group by multiple fields.

       SetHost Host
       SetPlugin Plugin
       SetPluginInstance PluginInstance
       SetTypeInstance TypeInstance
           Sets the appropriate part of the identifier to the provided string.

           The PluginInstance should include the placeholder "%{aggregation}" which will be replaced with the
           aggregation function, e.g. "average". Not including the placeholder will result in duplication
           warnings and/or messed up values if more than one aggregation function are enabled.

           The following example calculates the average usage of all "even" CPUs:

            <Plugin "aggregation">
              <Aggregation>
                Plugin "cpu"
                PluginInstance "/[0,2,4,6,8]$/"
                Type "cpu"

                SetPlugin "cpu"
                SetPluginInstance "even-%{aggregation}"

                GroupBy "Host"
                GroupBy "TypeInstance"

                CalculateAverage true
              </Aggregation>
            </Plugin>

           This will create the files:

           •   foo.example.com/cpu-even-average/cpu-idle

           •   foo.example.com/cpu-even-average/cpu-system

           •   foo.example.com/cpu-even-average/cpu-user

           •   ...

       CalculateNum true|false
       CalculateSum true|false
       CalculateAverage true|false
       CalculateMinimum true|false
       CalculateMaximum true|false
       CalculateStddev true|false
           Boolean options for enabling calculation of the number of value lists, their sum, average, minimum,
           maximum and / or standard deviation. All options are disabled by default.

   Plugin "amqp"
       The AMQP plugin can be used to communicate with other instances of collectd or third party applications
       using an AMQP message broker. Values are sent to or received from the broker, which handles routing,
       queueing and possibly filtering out messages.

       Synopsis:

        <Plugin "amqp">
          # Send values to an AMQP broker
          <Publish "some_name">
            Host "localhost"
            Port "5672"
            VHost "/"
            User "guest"
            Password "guest"
            Exchange "amq.fanout"
        #   ExchangeType "fanout"
        #   RoutingKey "collectd"
        #   Persistent false
        #   ConnectionRetryDelay 0
        #   Format "command"
        #   StoreRates false
        #   GraphitePrefix "collectd."
        #   GraphiteEscapeChar "_"
        #   GraphiteSeparateInstances false
        #   GraphiteAlwaysAppendDS false
        #   GraphitePreserveSeparator false
          </Publish>

          # Receive values from an AMQP broker
          <Subscribe "some_name">
            Host "localhost"
            Port "5672"
            VHost "/"
            User "guest"
            Password "guest"
            Exchange "amq.fanout"
        #   ExchangeType "fanout"
        #   Queue "queue_name"
        #   QueueDurable false
        #   QueueAutoDelete true
        #   RoutingKey "collectd.#"
        #   ConnectionRetryDelay 0
          </Subscribe>
        </Plugin>

       The plugin's configuration consists of a number of Publish and Subscribe blocks, which configure sending
       and receiving of values respectively. The two blocks are very similar, so unless otherwise noted, an
       option can be used in either block. The name given in the blocks starting tag is only used for reporting
       messages, but may be used to support flushing of certain Publish blocks in the future.

       Host Host
           Hostname or IP-address of the AMQP broker. Defaults to the default behavior of the underlying
           communications library, rabbitmq-c, which is "localhost".

       Port Port
           Service name or port number on which the AMQP broker accepts connections. This argument must be a
           string, even if the numeric form is used. Defaults to "5672".

       VHost VHost
           Name of the virtual host on the AMQP broker to use. Defaults to "/".

       User User
       Password Password
           Credentials used to authenticate to the AMQP broker. By default "guest"/"guest" is used.

       Exchange Exchange
           In Publish blocks, this option specifies the exchange to send values to.  By default, "amq.fanout"
           will be used.

           In Subscribe blocks this option is optional. If given, a binding between the given exchange and the
           queue is created, using the routing key if configured. See the Queue and RoutingKey options below.

       ExchangeType Type
           If given, the plugin will try to create the configured exchange with this type after connecting. When
           in a Subscribe block, the queue will then be bound to this exchange.

       Queue Queue (Subscribe only)
           Configures the queue name to subscribe to. If no queue name was configured explicitly, a unique queue
           name will be created by the broker.

       QueueDurable true|false (Subscribe only)
           Defines if the queue subscribed to is durable (saved to persistent storage) or transient (will
           disappear if the AMQP broker is restarted). Defaults to "false".

           This option should be used in conjunction with the Persistent option on the publish side.

       QueueAutoDelete true|false (Subscribe only)
           Defines if the queue subscribed to will be deleted once the last consumer unsubscribes. Defaults to
           "true".

       RoutingKey Key
           In Publish blocks, this configures the routing key to set on all outgoing messages. If not given, the
           routing key will be computed from the identifier of the value. The host, plugin, type and the two
           instances are concatenated together using dots as the separator and all containing dots replaced with
           slashes. For example "collectd.host/example/com.cpu.0.cpu.user". This makes it possible to receive
           only specific values using a "topic" exchange.

           In Subscribe blocks, configures the routing key used when creating a binding between an exchange and
           the queue. The usual wildcards can be used to filter messages when using a "topic" exchange. If
           you're only interested in CPU statistics, you could use the routing key "collectd.*.cpu.#" for
           example.

       Persistent true|false (Publish only)
           Selects the delivery method to use. If set to true, the persistent mode will be used, i.e. delivery
           is guaranteed. If set to false (the default), the transient delivery mode will be used, i.e. messages
           may be lost due to high load, overflowing queues or similar issues.

       ConnectionRetryDelay Delay
           When the connection to the AMQP broker is lost, defines the time in seconds to wait before attempting
           to reconnect. Defaults to 0, which implies collectd will attempt to reconnect at each read interval
           (in Subscribe mode) or each time values are ready for submission (in Publish mode).

       Format Command|JSON|Graphite (Publish only)
           Selects the format in which messages are sent to the broker. If set to Command (the default), values
           are sent as "PUTVAL" commands which are identical to the syntax used by the Exec and UnixSock
           plugins. In this case, the "Content-Type" header field will be set to "text/collectd".

           If set to JSON, the values are encoded in the JavaScript Object Notation, an easy and straight
           forward exchange format. The "Content-Type" header field will be set to "application/json".

           If set to Graphite, values are encoded in the Graphite format, which is "<metric> <value>
           <timestamp>\n". The "Content-Type" header field will be set to "text/graphite".

           A subscribing client should use the "Content-Type" header field to determine how to decode the
           values. Currently, the AMQP plugin itself can only decode the Command format.

       StoreRates true|false (Publish only)
           Determines whether or not "COUNTER", "DERIVE" and "ABSOLUTE" data sources are converted to a rate
           (i.e. a "GAUGE" value). If set to false (the default), no conversion is performed. Otherwise the
           conversion is performed using the internal value cache.

           Please note that currently this option is only used if the Format option has been set to JSON.

       GraphitePrefix (Publish and Format=Graphite only)
           A prefix can be added in the metric name when outputting in the Graphite format.  It's added before
           the Host name.  Metric name will be "<prefix><host><postfix><plugin><type><name>"

       GraphitePostfix (Publish and Format=Graphite only)
           A postfix can be added in the metric name when outputting in the Graphite format.  It's added after
           the Host name.  Metric name will be "<prefix><host><postfix><plugin><type><name>"

       GraphiteEscapeChar (Publish and Format=Graphite only)
           Specify a character to replace dots (.) in the host part of the metric name.  In Graphite metric
           name, dots are used as separators between different metric parts (host, plugin, type).  Default is
           "_" (Underscore).

       GraphiteSeparateInstances true|false
           If set to true, the plugin instance and type instance will be in their own path component, for
           example "host.cpu.0.cpu.idle". If set to false (the default), the plugin and plugin instance (and
           likewise the type and type instance) are put into one component, for example "host.cpu-0.cpu-idle".

       GraphiteAlwaysAppendDS true|false
           If set to true, append the name of the Data Source (DS) to the "metric" identifier. If set to false
           (the default), this is only done when there is more than one DS.

       GraphitePreserveSeparator false|true
           If set to false (the default) the "." (dot) character is replaced with GraphiteEscapeChar. Otherwise,
           if set to true, the "." (dot) character is preserved, i.e. passed through.

   Plugin "apache"
       To configure the "apache"-plugin you first need to configure the Apache webserver correctly. The Apache-
       plugin "mod_status" needs to be loaded and working and the "ExtendedStatus" directive needs to be
       enabled. You can use the following snipped to base your Apache config upon:

         ExtendedStatus on
         <IfModule mod_status.c>
           <Location /mod_status>
             SetHandler server-status
           </Location>
         </IfModule>

       Since its "mod_status" module is very similar to Apache's, lighttpd is also supported. It introduces a
       new field, called "BusyServers", to count the number of currently connected clients. This field is also
       supported.

       The configuration of the Apache plugin consists of one or more "<Instance />" blocks. Each block requires
       one string argument as the instance name. For example:

        <Plugin "apache">
          <Instance "www1">
            URL "http://www1.example.com/mod_status?auto"
          </Instance>
          <Instance "www2">
            URL "http://www2.example.com/mod_status?auto"
          </Instance>
        </Plugin>

       The instance name will be used as the plugin instance. To emulate the old (version 4) behavior, you can
       use an empty string (""). In order for the plugin to work correctly, each instance name must be unique.
       This is not enforced by the plugin and it is your responsibility to ensure it.

       The following options are accepted within each Instance block:

       URL http://host/mod_status?auto
           Sets the URL of the "mod_status" output. This needs to be the output generated by "ExtendedStatus on"
           and it needs to be the machine readable output generated by appending the "?auto" argument. This
           option is mandatory.

       User Username
           Optional user name needed for authentication.

       Password Password
           Optional password needed for authentication.

       VerifyPeer true|false
           Enable or disable peer SSL certificate verification. See <http://curl.haxx.se/docs/sslcerts.html> for
           details. Enabled by default.

       VerifyHost true|false
           Enable or disable peer host name verification. If enabled, the plugin checks if the "Common Name" or
           a "Subject Alternate Name" field of the SSL certificate matches the host name provided by the URL
           option. If this identity check fails, the connection is aborted. Obviously, only works when
           connecting to a SSL enabled server. Enabled by default.

       CACert File
           File that holds one or more SSL certificates. If you want to use HTTPS you will possibly need this
           option. What CA certificates come bundled with "libcurl" and are checked by default depends on the
           distribution you use.

       SSLCiphers list of ciphers
           Specifies which ciphers to use in the connection. The list of ciphers must specify valid ciphers. See
           <http://www.openssl.org/docs/apps/ciphers.html> for details.

       Timeout Milliseconds
           The Timeout option sets the overall timeout for HTTP requests to URL, in milliseconds. By default,
           the configured Interval is used to set the timeout.

   Plugin "apcups"
       Host Hostname
           Hostname of the host running apcupsd. Defaults to localhost. Please note that IPv6 support has been
           disabled unless someone can confirm or decline that apcupsd can handle it.

       Port Port
           TCP-Port to connect to. Defaults to 3551.

       ReportSeconds true|false
           If set to true, the time reported in the "timeleft" metric will be converted to seconds. This is the
           recommended setting. If set to false, the default for backwards compatibility, the time will be
           reported in minutes.

       PersistentConnection true|false
           The plugin is designed to keep the connection to apcupsd open between reads.  If plugin poll interval
           is greater than 15 seconds (hardcoded socket close timeout in apcupsd NIS), then this option is false
           by default.

           You can instruct the plugin to close the connection after each read by setting this option to false
           or force keeping the connection by setting it to true.

           If apcupsd appears to close the connection due to inactivity quite quickly, the plugin will try to
           detect this problem and switch to an open-read-close mode.

   Plugin "aquaero"
       This plugin collects the value of the available sensors in an Aquaero 5 board. Aquaero 5 is a water-
       cooling controller board, manufactured by Aqua Computer GmbH <http://www.aquacomputer.de/>, with a USB2
       connection for monitoring and configuration. The board can handle multiple temperature sensors, fans,
       water pumps and water level sensors and adjust the output settings such as fan voltage or power used by
       the water pump based on the available inputs using a configurable controller included in the board.  This
       plugin collects all the available inputs as well as some of the output values chosen by this controller.
       The plugin is based on the libaquaero5 library provided by aquatools-ng.

       Device DevicePath
           Device path of the Aquaero 5's USB HID (human interface device), usually in the form
           "/dev/usb/hiddevX". If this option is no set the plugin will try to auto-detect the Aquaero 5 USB
           device based on vendor-ID and product-ID.

   Plugin "ascent"
       This plugin collects information about an Ascent server, a free server for the "World of Warcraft" game.
       This plugin gathers the information by fetching the XML status page using "libcurl" and parses it using
       "libxml2".

       The configuration options are the same as for the "apache" plugin above:

       URL http://localhost/ascent/status/
           Sets the URL of the XML status output.

       User Username
           Optional user name needed for authentication.

       Password Password
           Optional password needed for authentication.

       VerifyPeer true|false
           Enable or disable peer SSL certificate verification. See <http://curl.haxx.se/docs/sslcerts.html> for
           details. Enabled by default.

       VerifyHost true|false
           Enable or disable peer host name verification. If enabled, the plugin checks if the "Common Name" or
           a "Subject Alternate Name" field of the SSL certificate matches the host name provided by the URL
           option. If this identity check fails, the connection is aborted. Obviously, only works when
           connecting to a SSL enabled server. Enabled by default.

       CACert File
           File that holds one or more SSL certificates. If you want to use HTTPS you will possibly need this
           option. What CA certificates come bundled with "libcurl" and are checked by default depends on the
           distribution you use.

       Timeout Milliseconds
           The Timeout option sets the overall timeout for HTTP requests to URL, in milliseconds. By default,
           the configured Interval is used to set the timeout.

   Plugin "barometer"
       This plugin reads absolute air pressure using digital barometer sensor on a I2C bus. Supported sensors
       are:

       MPL115A2 from Freescale, see <http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=MPL115A>.
       MPL3115 from Freescale see <http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=MPL3115A2>.
       BMP085 from Bosch Sensortec

       The sensor type - one of the above - is detected automatically by the plugin and indicated in the
       plugin_instance (you will see subdirectory "barometer-mpl115" or "barometer-mpl3115", or
       "barometer-bmp085"). The order of detection is BMP085 -> MPL3115 -> MPL115A2, the first one found will be
       used (only one sensor can be used by the plugin).

       The plugin provides absolute barometric pressure, air pressure reduced to sea level (several possible
       approximations) and as an auxiliary value also internal sensor temperature. It uses (expects/provides)
       typical metric units - pressure in [hPa], temperature in [C], altitude in [m].

       It was developed and tested under Linux only. The only platform dependency is the standard Linux i2c-dev
       interface (the particular bus driver has to support the SM Bus command subset).

       The reduction or normalization to mean sea level pressure requires (depending on selected
       method/approximation) also altitude and reference to temperature sensor(s).  When multiple temperature
       sensors are configured the minimum of their values is always used (expecting that the warmer ones are
       affected by e.g. direct sun light at that moment).

       Synopsis:

         <Plugin "barometer">
            Device            "/dev/i2c-0";
            Oversampling      512
            PressureOffset    0.0
            TemperatureOffset 0.0
            Normalization     2
            Altitude          238.0
            TemperatureSensor "myserver/onewire-F10FCA000800/temperature"
         </Plugin>

       Device device
           The only mandatory configuration parameter.

           Device name of the I2C bus to which the sensor is connected. Note that typically you need to have
           loaded the i2c-dev module.  Using i2c-tools you can check/list i2c buses available on your system by:

             i2cdetect -l

           Then you can scan for devices on given bus. E.g. to scan the whole bus 0 use:

             i2cdetect -y -a 0

           This way you should be able to verify that the pressure sensor (either type) is connected and
           detected on address 0x60.

       Oversampling value
           Optional parameter controlling the oversampling/accuracy. Default value is 1 providing fastest and
           least accurate reading.

           For MPL115 this is the size of the averaging window. To filter out sensor noise a simple averaging
           using floating window of this configurable size is used. The plugin will use average of the last
           "value" measurements (value of 1 means no averaging).  Minimal size is 1, maximal 1024.

           For MPL3115 this is the oversampling value. The actual oversampling is performed by the sensor and
           the higher value the higher accuracy and longer conversion time (although nothing to worry about in
           the collectd context).  Supported values are: 1, 2, 4, 8, 16, 32, 64 and 128. Any other value is
           adjusted by the plugin to the closest supported one.

           For BMP085 this is the oversampling value. The actual oversampling is performed by the sensor and the
           higher value the higher accuracy and longer conversion time (although nothing to worry about in the
           collectd context).  Supported values are: 1, 2, 4, 8. Any other value is adjusted by the plugin to
           the closest supported one.

       PressureOffset offset
           Optional parameter for MPL3115 only.

           You can further calibrate the sensor by supplying pressure and/or temperature offsets.  This is added
           to the measured/caclulated value (i.e. if the measured value is too high then use negative offset).
           In hPa, default is 0.0.

       TemperatureOffset offset
           Optional parameter for MPL3115 only.

           You can further calibrate the sensor by supplying pressure and/or temperature offsets.  This is added
           to the measured/caclulated value (i.e. if the measured value is too high then use negative offset).
           In C, default is 0.0.

       Normalization method
           Optional parameter, default value is 0.

           Normalization method - what approximation/model is used to compute the mean sea level pressure from
           the air absolute pressure.

           Supported values of the "method" (integer between from 0 to 2) are:

           0 - no conversion, absolute pressure is simply copied over. For this method you do not need to
           configure "Altitude" or "TemperatureSensor".
           1 - international formula for conversion , See
           <http://en.wikipedia.org/wiki/Atmospheric_pressure#Altitude_atmospheric_pressure_variation>. For this
           method you have to configure "Altitude" but do not need "TemperatureSensor" (uses fixed global
           temperature average instead).
           2 - formula as recommended by the Deutsche Wetterdienst (German Meteorological Service). See
           <http://de.wikipedia.org/wiki/Barometrische_H%C3%B6henformel#Theorie> For this method you have to
           configure both  "Altitude" and "TemperatureSensor".
       Altitude altitude
           The altitude (in meters) of the location where you meassure the pressure.

       TemperatureSensor reference
           Temperature sensor(s) which should be used as a reference when normalizing the pressure using
           "Normalization" method 2.  When specified more sensors a minimum is found and used each time.  The
           temperature reading directly from this pressure sensor/plugin is typically not suitable as the
           pressure sensor will be probably inside while we want outside temperature.  The collectd reference
           name is something like <hostname>/<plugin_name>-<plugin_instance>/<type>-<type_instance>
           (<type_instance> is usually omitted when there is just single value type). Or you can figure it out
           from the path of the output data files.

   Plugin "battery"
       The battery plugin reports the remaining capacity, power and voltage of laptop batteries.

       ValuesPercentage false|true
           When enabled, remaining capacity is reported as a percentage, e.g. "42% capacity remaining".
           Otherwise the capacity is stored as reported by the battery, most likely in "Wh". This option does
           not work with all input methods, in particular when only "/proc/pmu" is available on an old Linux
           system.  Defaults to false.

       ReportDegraded false|true
           Typical laptop batteries degrade over time, meaning the capacity decreases with recharge cycles. The
           maximum charge of the previous charge cycle is tracked as "last full capacity" and used to determine
           that a battery is "fully charged".

           When this option is set to false, the default, the battery plugin will only report the remaining
           capacity. If the ValuesPercentage option is enabled, the relative remaining capacity is calculated as
           the ratio of the "remaining capacity" and the "last full capacity". This is what most tools, such as
           the status bar of desktop environments, also do.

           When set to true, the battery plugin will report three values: charged (remaining capacity),
           discharged (difference between "last full capacity" and "remaining capacity") and degraded
           (difference between "design capacity" and "last full capacity").

       QueryStateFS false|true
           When set to true, the battery plugin will only read statistics related to battery performance as
           exposed by StateFS at /run/state. StateFS is used in Mer-based Sailfish OS, for example.

   Plugin "bind"
       Starting with BIND 9.5.0, the most widely used DNS server software provides extensive statistics about
       queries, responses and lots of other information.  The bind plugin retrieves this information that's
       encoded in XML and provided via HTTP and submits the values to collectd.

       To use this plugin, you first need to tell BIND to make this information available. This is done with the
       "statistics-channels" configuration option:

        statistics-channels {
          inet localhost port 8053;
        };

       The configuration follows the grouping that can be seen when looking at the data with an XSLT compatible
       viewer, such as a modern web browser. It's probably a good idea to make yourself familiar with the
       provided values, so you can understand what the collected statistics actually mean.

       Synopsis:

        <Plugin "bind">
          URL "http://localhost:8053/"
          ParseTime       false
          OpCodes         true
          QTypes          true

          ServerStats     true
          ZoneMaintStats  true
          ResolverStats   false
          MemoryStats     true

          <View "_default">
            QTypes        true
            ResolverStats true
            CacheRRSets   true

            Zone "127.in-addr.arpa/IN"
          </View>
        </Plugin>

       The bind plugin accepts the following configuration options:

       URL URL
           URL from which to retrieve the XML data. If not specified, "http://localhost:8053/" will be used.

       ParseTime true|false
           When set to true, the time provided by BIND will be parsed and used to dispatch the values. When set
           to false, the local time source is queried.

           This setting is set to true by default for backwards compatibility; setting this to false is
           recommended to avoid problems with timezones and localization.

       OpCodes true|false
           When enabled, statistics about the "OpCodes", for example the number of "QUERY" packets, are
           collected.

           Default: Enabled.

       QTypes true|false
           When enabled, the number of incoming queries by query types (for example "A", "MX", "AAAA") is
           collected.

           Default: Enabled.

       ServerStats true|false
           Collect global server statistics, such as requests received over IPv4 and IPv6, successful queries,
           and failed updates.

           Default: Enabled.

       ZoneMaintStats true|false
           Collect zone maintenance statistics, mostly information about notifications (zone updates) and zone
           transfers.

           Default: Enabled.

       ResolverStats true|false
           Collect resolver statistics, i. e. statistics about outgoing requests (e. g. queries over IPv4, lame
           servers). Since the global resolver counters apparently were removed in BIND 9.5.1 and 9.6.0, this is
           disabled by default. Use the ResolverStats option within a View "_default" block instead for the same
           functionality.

           Default: Disabled.

       MemoryStats
           Collect global memory statistics.

           Default: Enabled.

       Timeout Milliseconds
           The Timeout option sets the overall timeout for HTTP requests to URL, in milliseconds. By default,
           the configured Interval is used to set the timeout.

       View Name
           Collect statistics about a specific "view". BIND can behave different, mostly depending on the source
           IP-address of the request. These different configurations are called "views". If you don't use this
           feature, you most likely are only interested in the "_default" view.

           Within a <View name> block, you can specify which information you want to collect about a view. If no
           View block is configured, no detailed view statistics will be collected.

           QTypes true|false
               If enabled, the number of outgoing queries by query type (e. g. "A", "MX") is collected.

               Default: Enabled.

           ResolverStats true|false
               Collect resolver statistics, i. e. statistics about outgoing requests (e. g. queries over IPv4,
               lame servers).

               Default: Enabled.

           CacheRRSets true|false
               If enabled, the number of entries ("RR sets") in the view's cache by query type is collected.
               Negative entries (queries which resulted in an error, for example names that do not exist) are
               reported with a leading exclamation mark, e. g. "!A".

               Default: Enabled.

           Zone Name
               When given, collect detailed information about the given zone in the view. The information
               collected if very similar to the global ServerStats information (see above).

               You can repeat this option to collect detailed information about multiple zones.

               By default no detailed zone information is collected.

   Plugin "ceph"
       The ceph plugin collects values from JSON data to be parsed by libyajl (<https://lloyd.github.io/yajl/>)
       retrieved from ceph daemon admin sockets.

       A separate Daemon block must be configured for each ceph daemon to be monitored. The following example
       will read daemon statistics from four separate ceph daemons running on the same device (two OSDs, one
       MON, one MDS) :

         <Plugin ceph>
           LongRunAvgLatency false
           ConvertSpecialMetricTypes true
           <Daemon "osd.0">
             SocketPath "/var/run/ceph/ceph-osd.0.asok"
           </Daemon>
           <Daemon "osd.1">
             SocketPath "/var/run/ceph/ceph-osd.1.asok"
           </Daemon>
           <Daemon "mon.a">
             SocketPath "/var/run/ceph/ceph-mon.ceph1.asok"
           </Daemon>
           <Daemon "mds.a">
             SocketPath "/var/run/ceph/ceph-mds.ceph1.asok"
           </Daemon>
         </Plugin>

       The ceph plugin accepts the following configuration options:

       LongRunAvgLatency true|false
           If enabled, latency values(sum,count pairs) are calculated as the long run average - average since
           the ceph daemon was started = (sum / count).  When disabled, latency values are calculated as the
           average since the last collection = (sum_now - sum_last) / (count_now - count_last).

           Default: Disabled

       ConvertSpecialMetricTypes true|false
           If enabled, special metrics (metrics that differ in type from similar counters) are converted to the
           type of those similar counters. This currently only applies to filestore.journal_wr_bytes which is a
           counter for OSD daemons. The ceph schema reports this metric type as a sum,count pair while similar
           counters are treated as derive types. When converted, the sum is used as the counter value and is
           treated as a derive type.  When disabled, all metrics are treated as the types received from the ceph
           schema.

           Default: Enabled

       Each Daemon block must have a string argument for the plugin instance name.  A SocketPath is also
       required for each Daemon block:

       Daemon DaemonName
           Name to be used as the instance name for this daemon.

       SocketPath SocketPath
           Specifies the path to the UNIX admin socket of the ceph daemon.

   Plugin "cgroups"
       This plugin collects the CPU user/system time for each cgroup by reading the cpuacct.stat files in the
       first cpuacct-mountpoint (typically /sys/fs/cgroup/cpu.cpuacct on machines using systemd).

       CGroup Directory
           Select cgroup based on the name. Whether only matching cgroups are collected or if they are ignored
           is controlled by the IgnoreSelected option; see below.

           See /"IGNORELISTS" for details.

       IgnoreSelected true|false
           Invert the selection: If set to true, all cgroups except the ones that match any one of the criteria
           are collected. By default only selected cgroups are collected if a selection is made. If no selection
           is configured at all, all cgroups are selected.

   Plugin "chrony"
       The "chrony" plugin collects ntp data from a chronyd server, such as clock skew and per-peer stratum.

       For talking to chronyd, it mimics what the chronyc control program does on the wire.

       Available configuration options for the "chrony" plugin:

       Host Hostname
           Hostname of the host running chronyd. Defaults to localhost.

       Port Port
           UDP-Port to connect to. Defaults to 323.

       Timeout Timeout
           Connection timeout in seconds. Defaults to 2.

   Plugin "conntrack"
       This plugin collects IP conntrack statistics.

       OldFiles
           Assume the conntrack_count and conntrack_max files to be found in /proc/sys/net/ipv4/netfilter
           instead of /proc/sys/net/netfilter/.

   Plugin "cpu"
       The CPU plugin collects CPU usage metrics. By default, CPU usage is reported as Jiffies, using the "cpu"
       type. Two aggregations are available:

       •   Sum, per-state, over all CPUs installed in the system; and

       •   Sum, per-CPU, over all non-idle states of a CPU, creating an "active" state.

       The two aggregations can be combined, leading to collectd only emitting a single "active" metric for the
       entire system. As soon as one of these aggregations (or both) is enabled, the cpu plugin will report a
       percentage, rather than Jiffies. In addition, you can request individual, per-state, per-CPU metrics to
       be reported as percentage.

       The following configuration options are available:

       ReportByState true|false
           When set to true, the default, reports per-state metrics, e.g. "system", "user" and "idle".  When set
           to false, aggregates (sums) all non-idle states into one "active" metric.

       ReportByCpu true|false
           When set to true, the default, reports per-CPU (per-core) metrics.  When set to false, instead of
           reporting metrics for individual CPUs, only a global sum of CPU states is emitted.

       ValuesPercentage false|true
           This option is only considered when both, ReportByCpu and ReportByState are set to true. In this
           case, by default, metrics will be reported as Jiffies. By setting this option to true, you can
           request percentage values in the un-aggregated (per-CPU, per-state) mode as well.

       ReportNumCpu false|true
           When set to true, reports the number of available CPUs.  Defaults to false.

   Plugin "cpufreq"
       This plugin doesn't have any options. It reads /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq (for
       the first CPU installed) to get the current CPU frequency. If this file does not exist make sure cpufreqd
       (<http://cpufreqd.sourceforge.net/>) or a similar tool is installed and an "cpu governor" (that's a
       kernel module) is loaded.

   Plugin "cpusleep"
       This plugin doesn't have any options. It reads CLOCK_BOOTTIME and CLOCK_MONOTONIC and reports the
       difference between these clocks. Since BOOTTIME clock increments while device is suspended and MONOTONIC
       clock does not, the derivative of the difference between these clocks gives the relative amount of time
       the device has spent in suspend state. The recorded value is in milliseconds of sleep per seconds of wall
       clock.

   Plugin "csv"
       DataDir Directory
           Set the directory to store CSV-files under. Per default CSV-files are generated beneath the daemon's
           working directory, i. e. the BaseDir.  The special strings stdout and stderr can be used to write to
           the standard output and standard error channels, respectively. This, of course, only makes much sense
           when collectd is running in foreground- or non-daemon-mode.

       StoreRates true|false
           If set to true, convert counter values to rates. If set to false (the default) counter values are
           stored as is, i. e. as an increasing integer number.

   cURL Statistics
       All cURL-based plugins support collection of generic, request-based statistics. These are disabled by
       default and can be enabled selectively for each page or URL queried from the curl, curl_json, or curl_xml
       plugins. See the documentation of those plugins for specific information. This section describes the
       available metrics that can be configured for each plugin. All options are disabled by default.

       See <http://curl.haxx.se/libcurl/c/curl_easy_getinfo.html> for more details.

       TotalTime true|false
           Total time of the transfer, including name resolving, TCP connect, etc.

       NamelookupTime true|false
           Time it took from the start until name resolving was completed.

       ConnectTime true|false
           Time it took from the start until the connect to the remote host (or proxy) was completed.

       AppconnectTime true|false
           Time it took from the start until the SSL/SSH connect/handshake to the remote host was completed.

       PretransferTime true|false
           Time it took from the start until just before the transfer begins.

       StarttransferTime true|false
           Time it took from the start until the first byte was received.

       RedirectTime true|false
           Time it took for all redirection steps include name lookup, connect, pre-transfer and transfer before
           final transaction was started.

       RedirectCount true|false
           The total number of redirections that were actually followed.

       SizeUpload true|false
           The total amount of bytes that were uploaded.

       SizeDownload true|false
           The total amount of bytes that were downloaded.

       SpeedDownload true|false
           The average download speed that curl measured for the complete download.

       SpeedUpload true|false
           The average upload speed that curl measured for the complete upload.

       HeaderSize true|false
           The total size of all the headers received.

       RequestSize true|false
           The total size of the issued requests.

       ContentLengthDownload true|false
           The content-length of the download.

       ContentLengthUpload true|false
           The specified size of the upload.

       NumConnects true|false
           The number of new connections that were created to achieve the transfer.

   Plugin "curl"
       The curl plugin uses the libcurl (<http://curl.haxx.se/>) to read web pages and the match infrastructure
       (the same code used by the tail plugin) to use regular expressions with the received data.

       The following example will read the current value of AMD stock from Google's finance page and dispatch
       the value to collectd.

         <Plugin curl>
           <Page "stock_quotes">
             URL "http://finance.google.com/finance?q=NYSE%3AAMD"
             User "foo"
             Password "bar"
             Digest false
             VerifyPeer true
             VerifyHost true
             CACert "/path/to/ca.crt"
             Header "X-Custom-Header: foobar"
             Post "foo=bar"

             MeasureResponseTime false
             MeasureResponseCode false

             <Match>
               Regex "<span +class=\"pr\"[^>]*> *([0-9]*\\.[0-9]+) *</span>"
               DSType "GaugeAverage"
               # Note: `stock_value' is not a standard type.
               Type "stock_value"
               Instance "AMD"
             </Match>
           </Page>
         </Plugin>

       In the Plugin block, there may be one or more Page blocks, each defining a web page and one or more
       "matches" to be performed on the returned data. The string argument to the Page block is used as plugin
       instance.

       The following options are valid within Page blocks:

       URL URL
           URL of the web site to retrieve. Since a regular expression will be used to extract information from
           this data, non-binary data is a big plus here ;)

       User Name
           Username to use if authorization is required to read the page.

       Password Password
           Password to use if authorization is required to read the page.

       Digest true|false
           Enable HTTP digest authentication.

       VerifyPeer true|false
           Enable or disable peer SSL certificate verification. See <http://curl.haxx.se/docs/sslcerts.html> for
           details. Enabled by default.

       VerifyHost true|false
           Enable or disable peer host name verification. If enabled, the plugin checks if the "Common Name" or
           a "Subject Alternate Name" field of the SSL certificate matches the host name provided by the URL
           option. If this identity check fails, the connection is aborted. Obviously, only works when
           connecting to a SSL enabled server. Enabled by default.

       CACert file
           File that holds one or more SSL certificates. If you want to use HTTPS you will possibly need this
           option. What CA certificates come bundled with "libcurl" and are checked by default depends on the
           distribution you use.

       Header Header
           A HTTP header to add to the request. Multiple headers are added if this option is specified more than
           once.

       Post Body
           Specifies that the HTTP operation should be a POST instead of a GET. The complete data to be posted
           is given as the argument.  This option will usually need to be accompanied by a Header option to set
           an appropriate "Content-Type" for the post body (e.g. to "application/x-www-form-urlencoded").

       MeasureResponseTime true|false
           Measure response time for the request. If this setting is enabled, Match blocks (see below) are
           optional. Disabled by default.

           Beware that requests will get aborted if they take too long to complete. Adjust Timeout accordingly
           if you expect MeasureResponseTime to report such slow requests.

           This option is similar to enabling the TotalTime statistic but it's measured by collectd instead of
           cURL.

       MeasureResponseCode true|false
           Measure response code for the request. If this setting is enabled, Match blocks (see below) are
           optional. Disabled by default.

       <Statistics>
           One Statistics block can be used to specify cURL statistics to be collected for each request to the
           remote web site. See the section "cURL Statistics" above for details. If this setting is enabled,
           Match blocks (see below) are optional.

       <Match>
           One or more Match blocks that define how to match information in the data returned by "libcurl". The
           "curl" plugin uses the same infrastructure that's used by the "tail" plugin, so please see the
           documentation of the "tail" plugin below on how matches are defined. If the MeasureResponseTime or
           MeasureResponseCode options are set to true, Match blocks are optional.

       Timeout Milliseconds
           The Timeout option sets the overall timeout for HTTP requests to URL, in milliseconds. By default,
           the configured Interval is used to set the timeout. Prior to version 5.5.0, there was no timeout and
           requests could hang indefinitely. This legacy behaviour can be achieved by setting the value of
           Timeout to 0.

           If Timeout is 0 or bigger than the Interval, keep in mind that each slow network connection will
           stall one read thread. Adjust the ReadThreads global setting accordingly to prevent this from
           blocking other plugins.

   Plugin "curl_json"
       The curl_json plugin collects values from JSON data to be parsed by libyajl
       (<https://lloyd.github.io/yajl/>) retrieved via either libcurl (<http://curl.haxx.se/>) or read directly
       from a unix socket. The former can be used, for example, to collect values from CouchDB documents (which
       are stored JSON notation), and the latter to collect values from a uWSGI stats socket.

       The following example will collect several values from the built-in "_stats" runtime statistics module of
       CouchDB (<http://wiki.apache.org/couchdb/Runtime_Statistics>).

         <Plugin curl_json>
           <URL "http://localhost:5984/_stats">
             Instance "httpd"
             <Key "httpd/requests/count">
               Type "http_requests"
             </Key>

             <Key "httpd_request_methods/*/count">
               Type "http_request_methods"
             </Key>

             <Key "httpd_status_codes/*/count">
               Type "http_response_codes"
             </Key>
           </URL>
         </Plugin>

       This example will collect data directly from a uWSGI "Stats Server" socket.

         <Plugin curl_json>
           <Sock "/var/run/uwsgi.stats.sock">
             Instance "uwsgi"
             <Key "workers/*/requests">
               Type "http_requests"
             </Key>

             <Key "workers/*/apps/*/requests">
               Type "http_requests"
             </Key>
           </Sock>
         </Plugin>

       In the Plugin block, there may be one or more URL blocks, each defining a URL to be fetched via HTTP
       (using libcurl) or Sock blocks defining a unix socket to read JSON from directly.  Each of these blocks
       may have one or more Key blocks.

       The Key string argument must be in a path format. Each component is used to match the key from a JSON map
       or the index of an JSON array. If a path component of a Key is a * wildcard, the values for all map keys
       or array indices will be collectd.

       The following options are valid within URL blocks:

       Host Name
           Use Name as the host name when submitting values. Defaults to the global host name setting.

       Instance Instance
           Sets the plugin instance to Instance.

       Interval Interval
           Sets the interval (in seconds) in which the values will be collected from this URL. By default the
           global Interval setting will be used.

       User Name
       Password Password
       Digest true|false
       VerifyPeer true|false
       VerifyHost true|false
       CACert file
       Header Header
       Post Body
       Timeout Milliseconds
           These options behave exactly equivalent to the appropriate options of the cURL plugin. Please see
           there for a detailed description.

       <Statistics>
           One Statistics block can be used to specify cURL statistics to be collected for each request to the
           remote URL. See the section "cURL Statistics" above for details.

       The following options are valid within Key blocks:

       Type Type
           Sets the type used to dispatch the values to the daemon. Detailed information about types and their
           configuration can be found in types.db(5). This option is mandatory.

       Instance Instance
           Type-instance to use. Defaults to the current map key or current string array element value.

   Plugin "curl_xml"
       The curl_xml plugin uses libcurl (<http://curl.haxx.se/>) and libxml2 (<http://xmlsoft.org/>) to retrieve
       XML data via cURL.

        <Plugin "curl_xml">
          <URL "http://localhost/stats.xml">
            Host "my_host"
            Instance "some_instance"
            User "collectd"
            Password "thaiNg0I"
            VerifyPeer true
            VerifyHost true
            CACert "/path/to/ca.crt"
            Header "X-Custom-Header: foobar"
            Post "foo=bar"

            <XPath "table[@id=\"magic_level\"]/tr">
              Type "magic_level"
              #InstancePrefix "prefix-"
              InstanceFrom "td[1]"
              ValuesFrom "td[2]/span[@class=\"level\"]"
            </XPath>
          </URL>
        </Plugin>

       In the Plugin block, there may be one or more URL blocks, each defining a URL to be fetched using
       libcurl. Within each URL block there are options which specify the connection parameters, for example
       authentication information, and one or more XPath blocks.

       Each XPath block specifies how to get one type of information. The string argument must be a valid XPath
       expression which returns a list of "base elements". One value is dispatched for each "base element". The
       type instance and values are looked up using further XPath expressions that should be relative to the
       base element.

       Within the URL block the following options are accepted:

       Host Name
           Use Name as the host name when submitting values. Defaults to the global host name setting.

       Instance Instance
           Use Instance as the plugin instance when submitting values. Defaults to an empty string (no plugin
           instance).

       Namespace Prefix URL
           If an XPath expression references namespaces, they must be specified with this option. Prefix is the
           "namespace prefix" used in the XML document.  URL is the "namespace name", an URI reference uniquely
           identifying the namespace. The option can be repeated to register multiple namespaces.

           Examples:

             Namespace "s" "http://schemas.xmlsoap.org/soap/envelope/"
             Namespace "m" "http://www.w3.org/1998/Math/MathML"

       User User
       Password Password
       Digest true|false
       VerifyPeer true|false
       VerifyHost true|false
       CACert CA Cert File
       Header Header
       Post Body
       Timeout Milliseconds
           These options behave exactly equivalent to the appropriate options of the cURL plugin. Please see
           there for a detailed description.

       <Statistics>
           One Statistics block can be used to specify cURL statistics to be collected for each request to the
           remote URL. See the section "cURL Statistics" above for details.

       <XPath XPath-expression>
           Within each URL block, there must be one or more XPath blocks. Each XPath block specifies how to get
           one type of information. The string argument must be a valid XPath expression which returns a list of
           "base elements". One value is dispatched for each "base element".

           Within the XPath block the following options are accepted:

           Type Type
               Specifies the Type used for submitting patches. This determines the number of values that are
               required / expected and whether the strings are parsed as signed or unsigned integer or as double
               values. See types.db(5) for details.  This option is required.

           InstancePrefix InstancePrefix
               Prefix the type instance with InstancePrefix. The values are simply concatenated together without
               any separator.  This option is optional.

           InstanceFrom InstanceFrom
               Specifies a XPath expression to use for determining the type instance. The XPath expression must
               return exactly one element. The element's value is then used as type instance, possibly prefixed
               with InstancePrefix (see above).

               This value is required. As a special exception, if the "base XPath expression" (the argument to
               the XPath block) returns exactly one argument, then this option may be omitted.

           ValuesFrom ValuesFrom [ValuesFrom ...]
               Specifies one or more XPath expression to use for reading the values. The number of XPath
               expressions must match the number of data sources in the type specified with Type (see above).
               Each XPath expression must return exactly one element. The element's value is then parsed as a
               number and used as value for the appropriate value in the value list dispatched to the daemon.

   Plugin "dbi"
       This plugin uses the dbi library (<http://libdbi.sourceforge.net/>) to connect to various databases,
       execute SQL statements and read back the results. dbi is an acronym for "database interface" in case you
       were wondering about the name. You can configure how each column is to be interpreted and the plugin will
       generate one or more data sets from each row returned according to these rules.

       Because the plugin is very generic, the configuration is a little more complex than those of other
       plugins. It usually looks something like this:

         <Plugin dbi>
           <Query "out_of_stock">
             Statement "SELECT category, COUNT(*) AS value FROM products WHERE in_stock = 0 GROUP BY category"
             # Use with MySQL 5.0.0 or later
             MinVersion 50000
             <Result>
               Type "gauge"
               InstancePrefix "out_of_stock"
               InstancesFrom "category"
               ValuesFrom "value"
             </Result>
           </Query>
           <Database "product_information">
             Driver "mysql"
             Interval 120
             DriverOption "host" "localhost"
             DriverOption "username" "collectd"
             DriverOption "password" "aZo6daiw"
             DriverOption "dbname" "prod_info"
             SelectDB "prod_info"
             Query "out_of_stock"
           </Database>
         </Plugin>

       The configuration above defines one query with one result and one database. The query is then linked to
       the database with the Query option within the <Database> block. You can have any number of queries and
       databases and you can also use the Include statement to split up the configuration file in multiple,
       smaller files. However, the <Query> block must precede the <Database> blocks, because the file is
       interpreted from top to bottom!

       The following is a complete list of options:

       Query blocks

       Query blocks define SQL statements and how the returned data should be interpreted. They are identified
       by the name that is given in the opening line of the block. Thus the name needs to be unique. Other than
       that, the name is not used in collectd.

       In each Query block, there is one or more Result blocks. Result blocks define which column holds which
       value or instance information. You can use multiple Result blocks to create multiple values from one
       returned row. This is especially useful, when queries take a long time and sending almost the same query
       again and again is not desirable.

       Example:

         <Query "environment">
           Statement "select station, temperature, humidity from environment"
           <Result>
             Type "temperature"
             # InstancePrefix "foo"
             InstancesFrom "station"
             ValuesFrom "temperature"
           </Result>
           <Result>
             Type "humidity"
             InstancesFrom "station"
             ValuesFrom "humidity"
           </Result>
         </Query>

       The following options are accepted:

       Statement SQL
           Sets the statement that should be executed on the server. This is not interpreted by collectd, but
           simply passed to the database server. Therefore, the SQL dialect that's used depends on the server
           collectd is connected to.

           The query has to return at least two columns, one for the instance and one value. You cannot omit the
           instance, even if the statement is guaranteed to always return exactly one line. In that case, you
           can usually specify something like this:

             Statement "SELECT \"instance\", COUNT(*) AS value FROM table"

           (That works with MySQL but may not be valid SQL according to the spec. If you use a more strict
           database server, you may have to select from a dummy table or something.)

           Please note that some databases, for example Oracle, will fail if you include a semicolon at the end
           of the statement.

       MinVersion Version
       MaxVersion Value
           Only use this query for the specified database version. You can use these options to provide multiple
           queries with the same name but with a slightly different syntax. The plugin will use only those
           queries, where the specified minimum and maximum versions fit the version of the database in use.

           The database version is determined by "dbi_conn_get_engine_version", see the libdbi documentation
           <http://libdbi.sourceforge.net/docs/programmers-guide/reference-conn.html#DBI-CONN-GET-ENGINE-
           VERSION> for details. Basically, each part of the version is assumed to be in the range from 00 to 99
           and all dots are removed. So version "4.1.2" becomes "40102", version "5.0.42" becomes "50042".

           Warning: The plugin will use all matching queries, so if you specify multiple queries with the same
           name and overlapping ranges, weird stuff will happen. Don't to it! A valid example would be something
           along these lines:

             MinVersion 40000
             MaxVersion 49999
             ...
             MinVersion 50000
             MaxVersion 50099
             ...
             MinVersion 50100
             # No maximum

           In the above example, there are three ranges that don't overlap. The last one goes from version
           "5.1.0" to infinity, meaning "all later versions". Versions before "4.0.0" are not specified.

       Type Type
           The type that's used for each line returned. See types.db(5) for more details on how types are
           defined. In short: A type is a predefined layout of data and the number of values and type of values
           has to match the type definition.

           If you specify "temperature" here, you need exactly one gauge column. If you specify "if_octets", you
           will need two counter columns. See the ValuesFrom setting below.

           There must be exactly one Type option inside each Result block.

       InstancePrefix prefix
           Prepends prefix to the type instance. If InstancesFrom (see below) is not given, the string is simply
           copied. If InstancesFrom is given, prefix and all strings returned in the appropriate columns are
           concatenated together, separated by dashes ("-").

       InstancesFrom column0 [column1 ...]
           Specifies the columns whose values will be used to create the "type-instance" for each row. If you
           specify more than one column, the value of all columns will be joined together with dashes ("-") as
           separation characters.

           The plugin itself does not check whether or not all built instances are different. It's your
           responsibility to assure that each is unique. This is especially true, if you do not specify
           InstancesFrom: You have to make sure that only one row is returned in this case.

           If neither InstancePrefix nor InstancesFrom is given, the type-instance will be empty.

       ValuesFrom column0 [column1 ...]
           Names the columns whose content is used as the actual data for the data sets that are dispatched to
           the daemon. How many such columns you need is determined by the Type setting above. If you specify
           too many or not enough columns, the plugin will complain about that and no data will be submitted to
           the daemon.

           The actual data type in the columns is not that important. The plugin will automatically cast the
           values to the right type if it know how to do that. So it should be able to handle integer an
           floating point types, as well as strings (if they include a number at the beginning).

           There must be at least one ValuesFrom option inside each Result block.

       MetadataFrom [column0 column1 ...]
           Names the columns whose content is used as metadata for the data sets that are dispatched to the
           daemon.

           The actual data type in the columns is not that important. The plugin will automatically cast the
           values to the right type if it know how to do that. So it should be able to handle integer an
           floating point types, as well as strings (if they include a number at the beginning).

       Database blocks

       Database blocks define a connection to a database and which queries should be sent to that database.
       Since the used "dbi" library can handle a wide variety of databases, the configuration is very generic.
       If in doubt, refer to libdbi's documentation - we stick as close to the terminology used there.

       Each database needs a "name" as string argument in the starting tag of the block. This name will be used
       as "PluginInstance" in the values submitted to the daemon. Other than that, that name is not used.

       Interval Interval
           Sets the interval (in seconds) in which the values will be collected from this database. By default
           the global Interval setting will be used.

       Driver Driver
           Specifies the driver to use to connect to the database. In many cases those drivers are named after
           the database they can connect to, but this is not a technical necessity. These drivers are sometimes
           referred to as "DBD", DataBase Driver, and some distributions ship them in separate packages. Drivers
           for the "dbi" library are developed by the libdbi-drivers project at
           <http://libdbi-drivers.sourceforge.net/>.

           You need to give the driver name as expected by the "dbi" library here. You should be able to find
           that in the documentation for each driver. If you mistype the driver name, the plugin will dump a
           list of all known driver names to the log.

       DriverOption Key Value
           Sets driver-specific options. What option a driver supports can be found in the documentation for
           each driver, somewhere at <http://libdbi-drivers.sourceforge.net/>. However, the options "host",
           "username", "password", and "dbname" seem to be de facto standards.

           DBDs can register two types of options: String options and numeric options. The plugin will use the
           "dbi_conn_set_option" function when the configuration provides a string and the
           "dbi_conn_require_option_numeric" function when the configuration provides a number. So these two
           lines will actually result in different calls being used:

             DriverOption "Port" 1234      # numeric
             DriverOption "Port" "1234"    # string

           Unfortunately, drivers are not too keen to report errors when an unknown option is passed to them, so
           invalid settings here may go unnoticed. This is not the plugin's fault, it will report errors if it
           gets them from the library / the driver. If a driver complains about an option, the plugin will dump
           a complete list of all options understood by that driver to the log. There is no way to
           programmatically find out if an option expects a string or a numeric argument, so you will have to
           refer to the appropriate DBD's documentation to find this out. Sorry.

       SelectDB Database
           In some cases, the database name you connect with is not the database name you want to use for
           querying data. If this option is set, the plugin will "select" (switch to) that database after the
           connection is established.

       Query QueryName
           Associates the query named QueryName with this database connection. The query needs to be defined
           before this statement, i. e. all query blocks you want to refer to must be placed above the database
           block you want to refer to them from.

       Host Hostname
           Sets the host field of value lists to Hostname when dispatching values. Defaults to the global
           hostname setting.

   Plugin "df"
       Device Device
           Select partitions based on the devicename.

           See /"IGNORELISTS" for details.

       MountPoint Directory
           Select partitions based on the mountpoint.

           See /"IGNORELISTS" for details.

       FSType FSType
           Select partitions based on the filesystem type.

           See /"IGNORELISTS" for details.

       IgnoreSelected true|false
           Invert the selection: If set to true, all partitions except the ones that match any one of the
           criteria are collected. By default only selected partitions are collected if a selection is made. If
           no selection is configured at all, all partitions are selected.

       ReportByDevice true|false
           Report using the device name rather than the mountpoint. i.e. with this false, (the default), it will
           report a disk as "root", but with it true, it will be "sda1" (or whichever).

       ReportInodes true|false
           Enables or disables reporting of free, reserved and used inodes. Defaults to inode collection being
           disabled.

           Enable this option if inodes are a scarce resource for you, usually because many small files are
           stored on the disk. This is a usual scenario for mail transfer agents and web caches.

       ValuesAbsolute true|false
           Enables or disables reporting of free and used disk space in 1K-blocks.  Defaults to true.

       ValuesPercentage false|true
           Enables or disables reporting of free and used disk space in percentage.  Defaults to false.

           This is useful for deploying collectd on the cloud, where machines with different disk size may
           exist. Then it is more practical to configure thresholds based on relative disk size.

   Plugin "disk"
       The "disk" plugin collects information about the usage of physical disks and logical disks (partitions).
       Values collected are the number of octets written to and read from a disk or partition, the number of
       read/write operations issued to the disk and a rather complex "time" it took for these commands to be
       issued.

       Using the following two options you can ignore some disks or configure the collection only of specific
       disks.

       Disk Name
           Select the disk Name. Whether it is collected or ignored depends on the IgnoreSelected setting, see
           below. As with other plugins that use the daemon's ignorelist functionality, a string that starts and
           ends with a slash is interpreted as a regular expression. Examples:

             Disk "sdd"
             Disk "/hda[34]/"

           See /"IGNORELISTS" for details.

       IgnoreSelected true|false
           Sets whether selected disks, i. e. the ones matches by any of the Disk statements, are ignored or if
           all other disks are ignored. The behavior (hopefully) is intuitive: If no Disk option is configured,
           all disks are collected. If at least one Disk option is given and no IgnoreSelected or set to false,
           only matching disks will be collected. If IgnoreSelected is set to true, all disks are collected
           except the ones matched.

       UseBSDName true|false
           Whether to use the device's "BSD Name", on Mac OS X, instead of the default major/minor numbers.
           Requires collectd to be built with Apple's IOKitLib support.

       UdevNameAttr Attribute
           Attempt to override disk instance name with the value of a specified udev attribute when built with
           libudev.  If the attribute is not defined for the given device, the default name is used. Example:

             UdevNameAttr "DM_NAME"

   Plugin "dns"
       Interface Interface
           The dns plugin uses libpcap to capture dns traffic and analyzes it. This option sets the interface
           that should be used. If this option is not set, or set to "any", the plugin will try to get packets
           from all interfaces. This may not work on certain platforms, such as Mac OS X.

       IgnoreSource IP-address
           Ignore packets that originate from this address.

       SelectNumericQueryTypes true|false
           Enabled by default, collects unknown (and thus presented as numeric only) query types.

   Plugin "dpdkstat"
       The dpdkstat plugin collects information about DPDK interfaces using the extended NIC stats API in DPDK.

       Synopsis:

        <Plugin "dpdkstat">
           Coremask "0x4"
           MemoryChannels "4"
           ProcessType "secondary"
           FilePrefix "rte"
           EnabledPortMask 0xffff
           PortName "interface1"
           PortName "interface2"
        </Plugin>

       Options:

       Coremask Mask
           A string containing an hexadecimal bit mask of the cores to run on. Note that core numbering can
           change between platforms and should be determined beforehand.

       Memorychannels Channels
           A string containing a number of memory channels per processor socket.

       ProcessType type
           A string containing the type of DPDK process instance.

       FilePrefix File
           The prefix text used for hugepage filenames. The filename will be set to /var/run/.<prefix>_config
           where prefix is what is passed in by the user.

       SocketMemory MB
           A string containing amount of Memory to allocate from hugepages on specific sockets in MB

       EnabledPortMask Mask
           A hexidecimal bit mask of the DPDK ports which should be enabled. A mask of 0x0 means that all ports
           will be disabled. A bitmask of all Fs means that all ports will be enabled. This is an optional
           argument - default is all ports enabled.

       PortName Name
           A string containing an optional name for the enabled DPDK ports. Each PortName option should contain
           only one port name; specify as many PortName options as desired. Default naming convention will be
           used if PortName is blank. If there are less PortName options than there are enabled ports, the
           default naming convention will be used for the additional ports.

   Plugin "email"
       SocketFile Path
           Sets the socket-file which is to be created.

       SocketGroup Group
           If running as root change the group of the UNIX-socket after it has been created. Defaults to
           collectd.

       SocketPerms Permissions
           Change the file permissions of the UNIX-socket after it has been created. The permissions must be
           given as a numeric, octal value as you would pass to chmod(1). Defaults to 0770.

       MaxConns Number
           Sets the maximum number of connections that can be handled in parallel. Since this many threads will
           be started immediately setting this to a very high value will waste valuable resources. Defaults to 5
           and will be forced to be at most 16384 to prevent typos and dumb mistakes.

   Plugin "ethstat"
       The ethstat plugin collects information about network interface cards (NICs) by talking directly with the
       underlying kernel driver using ioctl(2).

       Synopsis:

        <Plugin "ethstat">
          Interface "eth0"
          Map "rx_csum_offload_errors" "if_rx_errors" "checksum_offload"
          Map "multicast" "if_multicast"
        </Plugin>

       Options:

       Interface Name
           Collect statistical information about interface Name.

       Map Name Type [TypeInstance]
           By default, the plugin will submit values as type "derive" and type instance set to Name, the name of
           the metric as reported by the driver. If an appropriate Map option exists, the given Type and,
           optionally, TypeInstance will be used.

       MappedOnly true|false
           When set to true, only metrics that can be mapped to a type will be collected, all other metrics will
           be ignored. Defaults to false.

   Plugin "exec"
       Please make sure to read collectd-exec(5) before using this plugin. It contains valuable information on
       when the executable is executed and the output that is expected from it.

       Exec User[:[Group]] Executable [<arg> [<arg> ...]]
       NotificationExec User[:[Group]] Executable [<arg> [<arg> ...]]
           Execute the executable Executable as user User. If the user name is followed by a colon and a group
           name, the effective group is set to that group.  The real group and saved-set group will be set to
           the default group of that user. If no group is given the effective group ID will be the same as the
           real group ID.

           Please note that in order to change the user and/or group the daemon needs superuser privileges. If
           the daemon is run as an unprivileged user you must specify the same user/group here. If the daemon is
           run with superuser privileges, you must supply a non-root user here.

           The executable may be followed by optional arguments that are passed to the program. Please note that
           due to the configuration parsing numbers and boolean values may be changed. If you want to be
           absolutely sure that something is passed as-is please enclose it in quotes.

           The Exec and NotificationExec statements change the semantics of the programs executed, i. e. the
           data passed to them and the response expected from them. This is documented in great detail in
           collectd-exec(5).

   Plugin "fhcount"
       The "fhcount" plugin provides statistics about used, unused and total number of file handles on Linux.

       The fhcount plugin provides the following configuration options:

       ValuesAbsolute true|false
           Enables or disables reporting of file handles usage in absolute numbers, e.g. file handles used.
           Defaults to true.

       ValuesPercentage false|true
           Enables or disables reporting of file handles usage in percentages, e.g.  percent of file handles
           used. Defaults to false.

   Plugin "filecount"
       The "filecount" plugin counts the number of files in a certain directory (and its subdirectories) and
       their combined size. The configuration is very straight forward:

         <Plugin "filecount">
           <Directory "/var/qmail/queue/mess">
             Instance "qmail-message"
           </Directory>
           <Directory "/var/qmail/queue/todo">
             Instance "qmail-todo"
           </Directory>
           <Directory "/var/lib/php5">
             Instance "php5-sessions"
             Name "sess_*"
           </Directory>
         </Plugin>

       The example above counts the number of files in QMail's queue directories and the number of PHP5
       sessions. Jfiy: The "todo" queue holds the messages that QMail has not yet looked at, the "message" queue
       holds the messages that were classified into "local" and "remote".

       As you can see, the configuration consists of one or more "Directory" blocks, each of which specifies a
       directory in which to count the files. Within those blocks, the following options are recognized:

       Instance Instance
           Sets the plugin instance to Instance. That instance name must be unique, but it's your
           responsibility, the plugin doesn't check for that. If not given, the instance is set to the directory
           name with all slashes replaced by underscores and all leading underscores removed.

       Name Pattern
           Only count files that match Pattern, where Pattern is a shell-like wildcard as understood by
           fnmatch(3). Only the filename is checked against the pattern, not the entire path. In case this makes
           it easier for you: This option has been named after the -name parameter to find(1).

       MTime Age
           Count only files of a specific age: If Age is greater than zero, only files that haven't been touched
           in the last Age seconds are counted. If Age is a negative number, this is inversed. For example, if
           -60 is specified, only files that have been modified in the last minute will be counted.

           The number can also be followed by a "multiplier" to easily specify a larger timespan. When given in
           this notation, the argument must in quoted, i. e.  must be passed as string. So the -60 could also be
           written as "-1m" (one minute). Valid multipliers are "s" (second), "m" (minute), "h" (hour), "d"
           (day), "w" (week), and "y" (year). There is no "month" multiplier. You can also specify fractional
           numbers, e. g. "0.5d" is identical to "12h".

       Size Size
           Count only files of a specific size. When Size is a positive number, only files that are at least
           this big are counted. If Size is a negative number, this is inversed, i. e. only files smaller than
           the absolute value of Size are counted.

           As with the MTime option, a "multiplier" may be added. For a detailed description see above. Valid
           multipliers here are "b" (byte), "k" (kilobyte), "m" (megabyte), "g" (gigabyte), "t" (terabyte), and
           "p" (petabyte). Please note that there are 1000 bytes in a kilobyte, not 1024.

       Recursive true|false
           Controls whether or not to recurse into subdirectories. Enabled by default.

       IncludeHidden true|false
           Controls whether or not to include "hidden" files and directories in the count.  "Hidden" files and
           directories are those, whose name begins with a dot.  Defaults to false, i.e. by default hidden files
           and directories are ignored.

   Plugin "GenericJMX"
       The GenericJMX plugin is written in Java and therefore documented in collectd-java(5).

   Plugin "gmond"
       The gmond plugin received the multicast traffic sent by gmond, the statistics collection daemon of
       Ganglia. Mappings for the standard "metrics" are built-in, custom mappings may be added via Metric
       blocks, see below.

       Synopsis:

        <Plugin "gmond">
          MCReceiveFrom "239.2.11.71" "8649"
          <Metric "swap_total">
            Type "swap"
            TypeInstance "total"
            DataSource "value"
          </Metric>
          <Metric "swap_free">
            Type "swap"
            TypeInstance "free"
            DataSource "value"
          </Metric>
        </Plugin>

       The following metrics are built-in:

       •   load_one, load_five, load_fifteen

       •   cpu_user, cpu_system, cpu_idle, cpu_nice, cpu_wio

       •   mem_free, mem_shared, mem_buffers, mem_cached, mem_total

       •   bytes_in, bytes_out

       •   pkts_in, pkts_out

       Available configuration options:

       MCReceiveFrom MCGroup [Port]
           Sets sets the multicast group and UDP port to which to subscribe.

           Default: 239.2.11.71 / 8649

       <Metric Name>
           These blocks add a new metric conversion to the internal table. Name, the string argument to the
           Metric block, is the metric name as used by Ganglia.

           Type Type
               Type to map this metric to. Required.

           TypeInstance Instance
               Type-instance to use. Optional.

           DataSource Name
               Data source to map this metric to. If the configured type has exactly one data source, this is
               optional. Otherwise the option is required.

   Plugin "gps"
       The "gps plugin" connects to gpsd on the host machine.  The host, port, timeout and pause are
       configurable.

       This is useful if you run an NTP server using a GPS for source and you want to monitor it.

       Mind your GPS must send $--GSA for having the data reported!

       The following elements are collected:

       satellites
           Number of satellites used for fix (type instance "used") and in view (type instance "visible"). 0
           means no GPS satellites are visible.

       dilution_of_precision
           Vertical and horizontal dilution (type instance "horizontal" or "vertical").  It should be between 0
           and 3.  Look at the documentation of your GPS to know more.

       Synopsis:

        LoadPlugin gps
        <Plugin "gps">
          # Connect to localhost on gpsd regular port:
          Host "127.0.0.1"
          Port "2947"
          # 15 ms timeout
          Timeout 0.015
          # PauseConnect of 5 sec. between connection attempts.
          PauseConnect 5
        </Plugin>

       Available configuration options:

       Host Host
           The host on which gpsd daemon runs. Defaults to localhost.

       Port Port
           Port to connect to gpsd on the host machine. Defaults to 2947.

       Timeout Seconds
           Timeout in seconds (default 0.015 sec).

           The GPS data stream is fetch by the plugin form the daemon.  It waits for data to be available, if
           none arrives it times out and loop for another reading.  Mind to put a low value gpsd expects value
           in the micro-seconds area (recommended is 500 us) since the waiting function is blocking.  Value must
           be between 500 us and 5 sec., if outside that range the default value is applied.

           This only applies from gpsd release-2.95.

       PauseConnect Seconds
           Pause to apply between attempts of connection to gpsd in seconds (default 5 sec).

   Plugin "grpc"
       The grpc plugin provides an RPC interface to submit values to or query values from collectd based on the
       open source gRPC framework. It exposes an end-point for dispatching values to the daemon.

       The gRPC homepage can be found at <https://grpc.io/>.

       Server Host Port
           The Server statement sets the address of a server to which to send metrics via the "DispatchValues"
           function.

           The argument Host may be a hostname, an IPv4 address, or an IPv6 address.

           Optionally, Server may be specified as a configuration block which supports the following options:

           EnableSSL false|true
               Whether to require SSL for outgoing connections. Default: false.

           SSLCACertificateFile Filename
           SSLCertificateFile Filename
           SSLCertificateKeyFile Filename
               Filenames specifying SSL certificate and key material to be used with SSL connections.

       Listen Host Port
           The Listen statement sets the network address to bind to. When multiple statements are specified, the
           daemon will bind to all of them. If none are specified, it defaults to 0.0.0.0:50051.

           The argument Host may be a hostname, an IPv4 address, or an IPv6 address.

           Optionally, Listen may be specified as a configuration block which supports the following options:

           EnableSSL true|false
               Whether to enable SSL for incoming connections. Default: false.

           SSLCACertificateFile Filename
           SSLCertificateFile Filename
           SSLCertificateKeyFile Filename
               Filenames specifying SSL certificate and key material to be used with SSL connections.

   Plugin "hddtemp"
       To get values from hddtemp collectd connects to localhost (127.0.0.1), port 7634/tcp. The Host and Port
       options can be used to change these default values, see below. "hddtemp" has to be running to work
       correctly. If "hddtemp" is not running timeouts may appear which may interfere with other statistics..

       The hddtemp homepage can be found at <http://www.guzu.net/linux/hddtemp.php>.

       Host Hostname
           Hostname to connect to. Defaults to 127.0.0.1.

       Port Port
           TCP-Port to connect to. Defaults to 7634.

   Plugin "hugepages"
       To collect hugepages information, collectd reads directories "/sys/devices/system/node/*/hugepages" and
       "/sys/kernel/mm/hugepages".  Reading of these directories can be disabled by the following options
       (default is enabled).

       ReportPerNodeHP true|false
           If enabled, information will be collected from the hugepage counters in
           "/sys/devices/system/node/*/hugepages".  This is used to check the per-node hugepage statistics on a
           NUMA system.

       ReportRootHP true|false
           If enabled, information will be collected from the hugepage counters in "/sys/kernel/mm/hugepages".
           This can be used on both NUMA and non-NUMA systems to check the overall hugepage statistics.

       ValuesPages true|false
           Whether to report hugepages metrics in number of pages.  Defaults to true.

       ValuesBytes false|true
           Whether to report hugepages metrics in bytes.  Defaults to false.

       ValuesPercentage false|true
           Whether to report hugepages metrics as percentage.  Defaults to false.

   Plugin "intel_rdt"
       The intel_rdt plugin collects information provided by monitoring features of Intel Resource Director
       Technology (Intel(R) RDT) like Cache Monitoring Technology (CMT), Memory Bandwidth Monitoring (MBM).
       These features provide information about utilization of shared resources. CMT monitors last level cache
       occupancy (LLC). MBM supports two types of events reporting local and remote memory bandwidth. Local
       memory bandwidth (MBL) reports the bandwidth of accessing memory associated with the local socket. Remote
       memory bandwidth (MBR) reports the bandwidth of accessing the remote socket. Also this technology allows
       to monitor instructions per clock (IPC).  Monitor events are hardware dependant. Monitoring capabilities
       are detected on plugin initialization and only supported events are monitored.

       Synopsis:

         <Plugin "intel_rdt">
           Cores "0-2" "3,4,6" "8-10,15"
         </Plugin>

       Options:

       Interval seconds
           The interval within which to retrieve statistics on monitored events in seconds.  For milliseconds
           divide the time by 1000 for example if the desired interval is 50ms, set interval to 0.05. Due to
           limited capacity of counters it is not recommended to set interval higher than 1 sec.

       Cores cores groups
           All events are reported on a per core basis. Monitoring of the events can be configured for group of
           cores (aggregated statistics). This field defines groups of cores on which to monitor supported
           events. The field is represented as list of strings with core group values. Each string represents a
           list of cores in a group. Allowed formats are:
               0,1,2,3
               0-10,20-18
               1,3,5-8,10,0x10-12

           If an empty string is provided as value for this field default cores configuration is applied - a
           separate group is created for each core.

       Note: By default global interval is used to retrieve statistics on monitored events. To configure a
       plugin specific interval use Interval option of the intel_rdt <LoadPlugin> block. For milliseconds divide
       the time by 1000 for example if the desired interval is 50ms, set interval to 0.05.  Due to limited
       capacity of counters it is not recommended to set interval higher than 1 sec.

   Plugin "interface"
       Interface Interface
           Select this interface. By default these interfaces will then be collected. For a more detailed
           description see IgnoreSelected below.

           See /"IGNORELISTS" for details.

       IgnoreSelected true|false
           If no configuration if given, the interface-plugin will collect data from all interfaces. This may
           not be practical, especially for loopback- and similar interfaces. Thus, you can use the
           Interface-option to pick the interfaces you're interested in. Sometimes, however, it's
           easier/preferred to collect all interfaces except a few ones. This option enables you to do that: By
           setting IgnoreSelected to true the effect of Interface is inverted: All selected interfaces are
           ignored and all other interfaces are collected.

           It is possible to use regular expressions to match interface names, if the name is surrounded by
           /.../ and collectd was compiled with support for regexps. This is useful if there's a need to collect
           (or ignore) data for a group of interfaces that are similarly named, without the need to explicitly
           list all of them (especially useful if the list is dynamic).  Example:

            Interface "lo"
            Interface "/^veth/"
            Interface "/^tun[0-9]+/"
            IgnoreSelected "true"

           This will ignore the loopback interface, all interfaces with names starting with veth and all
           interfaces with names starting with tun followed by at least one digit.

       ReportInactive true|false
           When set to false, only interfaces with non-zero traffic will be reported. Note that the check is
           done by looking into whether a package was sent at any time from boot and the corresponding counter
           is non-zero. So, if the interface has been sending data in the past since boot, but not during the
           reported time-interval, it will still be reported.

           The default value is true and results in collection of the data from all interfaces that are selected
           by Interface and IgnoreSelected options.

       UniqueName true|false
           Interface name is not unique on Solaris (KSTAT), interface name is unique only within a
           module/instance. Following tuple is considered unique:
              (ks_module, ks_instance, ks_name) If this option is set to true, interface name contains above
           three fields separated by an underscore. For more info on KSTAT, visit
           <http://docs.oracle.com/cd/E23824_01/html/821-1468/kstat-3kstat.html#REFMAN3Ekstat-3kstat>

           This option is only available on Solaris.

   Plugin "ipmi"
       Sensor Sensor
           Selects sensors to collect or to ignore, depending on IgnoreSelected.

           See /"IGNORELISTS" for details.

       IgnoreSelected true|false
           If no configuration if given, the ipmi plugin will collect data from all sensors found of type
           "temperature", "voltage", "current" and "fanspeed".  This option enables you to do that: By setting
           IgnoreSelected to true the effect of Sensor is inverted: All selected sensors are ignored and all
           other sensors are collected.

       NotifySensorAdd true|false
           If a sensor appears after initialization time of a minute a notification is sent.

       NotifySensorRemove true|false
           If a sensor disappears a notification is sent.

       NotifySensorNotPresent true|false
           If you have for example dual power supply and one of them is (un)plugged then a notification is sent.

   Plugin "iptables"
       Chain Table Chain [Comment|Number [Name]]
       Chain6 Table Chain [Comment|Number [Name]]
           Select the iptables/ip6tables filter rules to count packets and bytes from.

           If only Table and Chain are given, this plugin will collect the counters of all rules which have a
           comment-match. The comment is then used as type-instance.

           If Comment or Number is given, only the rule with the matching comment or the nth rule will be
           collected. Again, the comment (or the number) will be used as the type-instance.

           If Name is supplied, it will be used as the type-instance instead of the comment or the number.

   Plugin "irq"
       Irq Irq
           Select this irq. By default these irqs will then be collected. For a more detailed description see
           IgnoreSelected below.

           See /"IGNORELISTS" for details.

       IgnoreSelected true|false
           If no configuration if given, the irq-plugin will collect data from all irqs. This may not be
           practical, especially if no interrupts happen. Thus, you can use the Irq-option to pick the interrupt
           you're interested in.  Sometimes, however, it's easier/preferred to collect all interrupts except a
           few ones. This option enables you to do that: By setting IgnoreSelected to true the effect of Irq is
           inverted: All selected interrupts are ignored and all other interrupts are collected.

   Plugin "java"
       The Java plugin makes it possible to write extensions for collectd in Java.  This section only discusses
       the syntax and semantic of the configuration options. For more in-depth information on the Java plugin,
       please read collectd-java(5).

       Synopsis:

        <Plugin "java">
          JVMArg "-verbose:jni"
          JVMArg "-Djava.class.path=/opt/collectd/lib/collectd/bindings/java"
          LoadPlugin "org.collectd.java.Foobar"
          <Plugin "org.collectd.java.Foobar">
            # To be parsed by the plugin
          </Plugin>
        </Plugin>

       Available configuration options:

       JVMArg Argument
           Argument that is to be passed to the Java Virtual Machine (JVM). This works exactly the way the
           arguments to the java binary on the command line work.  Execute "java --help" for details.

           Please note that all these options must appear before (i. e. above) any other options! When another
           option is found, the JVM will be started and later options will have to be ignored!

       LoadPlugin JavaClass
           Instantiates a new JavaClass object. The constructor of this object very likely then registers one or
           more callback methods with the server.

           See collectd-java(5) for details.

           When the first such option is found, the virtual machine (JVM) is created. This means that all JVMArg
           options must appear before (i. e. above) all LoadPlugin options!

       Plugin Name
           The entire block is passed to the Java plugin as an org.collectd.api.OConfigItem object.

           For this to work, the plugin has to register a configuration callback first, see "config callback" in
           collectd-java(5). This means, that the Plugin block must appear after the appropriate LoadPlugin
           block. Also note, that Name depends on the (Java) plugin registering the callback and is completely
           independent from the JavaClass argument passed to LoadPlugin.

   Plugin "load"
       The Load plugin collects the system load. These numbers give a rough overview over the utilization of a
       machine. The system load is defined as the number of runnable tasks in the run-queue and is provided by
       many operating systems as a one, five or fifteen minute average.

       The following configuration options are available:

       ReportRelative false|true
           When enabled, system load divided by number of available CPU cores is reported for intervals 1 min, 5
           min and 15 min. Defaults to false.

   Plugin "logfile"
       LogLevel debug|info|notice|warning|err
           Sets the log-level. If, for example, set to notice, then all events with severity notice, warning, or
           err will be written to the logfile.

           Please note that debug is only available if collectd has been compiled with debugging support.

       File File
           Sets the file to write log messages to. The special strings stdout and stderr can be used to write to
           the standard output and standard error channels, respectively. This, of course, only makes much sense
           when collectd is running in foreground- or non-daemon-mode.

       Timestamp true|false
           Prefix all lines printed by the current time. Defaults to true.

       PrintSeverity true|false
           When enabled, all lines are prefixed by the severity of the log message, for example "warning".
           Defaults to false.

       Note: There is no need to notify the daemon after moving or removing the log file (e. g. when rotating
       the logs). The plugin reopens the file for each line it writes.

   Plugin "log_logstash"
       The log logstash plugin behaves like the logfile plugin but formats messages as JSON events for logstash
       to parse and input.

       LogLevel debug|info|notice|warning|err
           Sets the log-level. If, for example, set to notice, then all events with severity notice, warning, or
           err will be written to the logfile.

           Please note that debug is only available if collectd has been compiled with debugging support.

       File File
           Sets the file to write log messages to. The special strings stdout and stderr can be used to write to
           the standard output and standard error channels, respectively. This, of course, only makes much sense
           when collectd is running in foreground- or non-daemon-mode.

       Note: There is no need to notify the daemon after moving or removing the log file (e. g. when rotating
       the logs). The plugin reopens the file for each line it writes.

   Plugin "lpar"
       The LPAR plugin reads CPU statistics of Logical Partitions, a virtualization technique for IBM POWER
       processors. It takes into account CPU time stolen from or donated to a partition, in addition to the
       usual user, system, I/O statistics.

       The following configuration options are available:

       CpuPoolStats false|true
           When enabled, statistics about the processor pool are read, too. The partition needs to have pool
           authority in order to be able to acquire this information.  Defaults to false.

       ReportBySerial false|true
           If enabled, the serial of the physical machine the partition is currently running on is reported as
           hostname and the logical hostname of the machine is reported in the plugin instance. Otherwise, the
           logical hostname will be used (just like other plugins) and the plugin instance will be empty.
           Defaults to false.

   Plugin "lua"
       This plugin embeds a Lua interpreter into collectd and provides an interface to collectd's plugin system.
       See collectd-lua(5) for its documentation.

   Plugin "mbmon"
       The "mbmon plugin" uses mbmon to retrieve temperature, voltage, etc.

       Be default collectd connects to localhost (127.0.0.1), port 411/tcp. The Host and Port options can be
       used to change these values, see below.  "mbmon" has to be running to work correctly. If "mbmon" is not
       running timeouts may appear which may interfere with other statistics..

       "mbmon" must be run with the -r option ("print TAG and Value format"); Debian's /etc/init.d/mbmon script
       already does this, other people will need to ensure that this is the case.

       Host Hostname
           Hostname to connect to. Defaults to 127.0.0.1.

       Port Port
           TCP-Port to connect to. Defaults to 411.

   Plugin "md"
       The "md plugin" collects information from Linux Software-RAID devices (md).

       All reported values are of the type "md_disks". Reported type instances are active, failed (present but
       not operational), spare (hot stand-by) and missing (physically absent) disks.

       Device Device
           Select md devices based on device name. The device name is the basename of the device, i.e. the name
           of the block device without the leading "/dev/".  See IgnoreSelected for more details.

           See /"IGNORELISTS" for details.

       IgnoreSelected true|false
           Invert device selection: If set to true, all md devices except those listed using Device are
           collected. If false (the default), only those listed are collected. If no configuration is given, the
           md plugin will collect data from all md devices.

   Plugin "memcachec"
       The "memcachec plugin" connects to a memcached server, queries one or more given pages and parses the
       returned data according to user specification.  The matches used are the same as the matches used in the
       "curl" and "tail" plugins.

       In order to talk to the memcached server, this plugin uses the libmemcached library. Please note that
       there is another library with a very similar name, libmemcache (notice the missing `d'), which is not
       applicable.

       Synopsis of the configuration:

        <Plugin "memcachec">
          <Page "plugin_instance">
            Server "localhost"
            Key "page_key"
            <Match>
              Regex "(\\d+) bytes sent"
              DSType CounterAdd
              Type "ipt_octets"
              Instance "type_instance"
            </Match>
          </Page>
        </Plugin>

       The configuration options are:

       <Page Name>
           Each Page block defines one page to be queried from the memcached server.  The block requires one
           string argument which is used as plugin instance.

       Server Address
           Sets the server address to connect to when querying the page. Must be inside a Page block.

       Key Key
           When connected to the memcached server, asks for the page Key.

       <Match>
           Match blocks define which strings to look for and how matches substrings are interpreted. For a
           description of match blocks, please see "Plugin tail".

   Plugin "memcached"
       The memcached plugin connects to a memcached server and queries statistics about cache utilization,
       memory and bandwidth used.  <http://memcached.org/>

        <Plugin "memcached">
          <Instance "name">
            #Host "memcache.example.com"
            Address "127.0.0.1"
            Port 11211
          </Instance>
        </Plugin>

       The plugin configuration consists of one or more Instance blocks which specify one memcached connection
       each. Within the Instance blocks, the following options are allowed:

       Host Hostname
           Sets the host field of dispatched values. Defaults to the global hostname setting.  For backwards
           compatibility, values are also dispatched with the global hostname when Host is set to 127.0.0.1 or
           localhost and Address is not set.

       Address Address
           Hostname or IP to connect to. For backwards compatibility, defaults to the value of Host or 127.0.0.1
           if Host is unset.

       Port Port
           TCP port to connect to. Defaults to 11211.

       Socket Path
           Connect to memcached using the UNIX domain socket at Path. If this setting is given, the Address and
           Port settings are ignored.

   Plugin "mic"
       The mic plugin gathers CPU statistics, memory usage and temperatures from Intel's Many Integrated Core
       (MIC) systems.

       Synopsis:

        <Plugin mic>
          ShowCPU true
          ShowCPUCores true
          ShowMemory true

          ShowTemperatures true
          Temperature vddg
          Temperature vddq
          IgnoreSelectedTemperature true

          ShowPower true
          Power total0
          Power total1
          IgnoreSelectedPower true
        </Plugin>

       The following options are valid inside the Plugin mic block:

       ShowCPU true|false
           If enabled (the default) a sum of the CPU usage across all cores is reported.

       ShowCPUCores true|false
           If enabled (the default) per-core CPU usage is reported.

       ShowMemory true|false
           If enabled (the default) the physical memory usage of the MIC system is reported.

       ShowTemperatures true|false
           If enabled (the default) various temperatures of the MIC system are reported.

       Temperature Name
           This option controls which temperatures are being reported. Whether matching temperatures are being
           ignored or only matching temperatures are reported depends on the IgnoreSelectedTemperature setting
           below. By default all temperatures are reported.

       IgnoreSelectedTemperature false|true
           Controls the behavior of the Temperature setting above. If set to false (the default) only
           temperatures matching a Temperature option are reported or, if no Temperature option is specified,
           all temperatures are reported. If set to true, matching temperatures are ignored and all other
           temperatures are reported.

           Known temperature names are:

           die Die of the CPU

           devmem
               Device Memory

           fin Fan In

           fout
               Fan Out

           vccp
               Voltage ccp

           vddg
               Voltage ddg

           vddq
               Voltage ddq

       ShowPower true|false
           If enabled (the default) various temperatures of the MIC system are reported.

       Power Name
           This option controls which power readings are being reported. Whether matching power readings are
           being ignored or only matching power readings are reported depends on the IgnoreSelectedPower setting
           below. By default all power readings are reported.

       IgnoreSelectedPower false|true
           Controls the behavior of the Power setting above. If set to false (the default) only power readings
           matching a Power option are reported or, if no Power option is specified, all power readings are
           reported. If set to true, matching power readings are ignored and all other power readings are
           reported.

           Known power names are:

           total0
               Total power utilization averaged over Time Window 0 (uWatts).

           total1
               Total power utilization averaged over Time Window 0 (uWatts).

           inst
               Instantaneous power (uWatts).

           imax
               Max instantaneous power (uWatts).

           pcie
               PCI-E connector power (uWatts).

           c2x3
               2x3 connector power (uWatts).

           c2x4
               2x4 connector power (uWatts).

           vccp
               Core rail (uVolts).

           vddg
               Uncore rail (uVolts).

           vddq
               Memory subsystem rail (uVolts).

   Plugin "memory"
       The memory plugin provides the following configuration options:

       ValuesAbsolute true|false
           Enables or disables reporting of physical memory usage in absolute numbers, i.e. bytes. Defaults to
           true.

       ValuesPercentage false|true
           Enables or disables reporting of physical memory usage in percentages, e.g.  percent of physical
           memory used. Defaults to false.

           This is useful for deploying collectd in a heterogeneous environment in which the sizes of physical
           memory vary.

   Plugin "modbus"
       The modbus plugin connects to a Modbus "slave" via Modbus/TCP or Modbus/RTU and reads register values. It
       supports reading single registers (unsigned 16 bit values), large integer values (unsigned 32 bit values)
       and floating point values (two registers interpreted as IEEE floats in big endian notation).

       Synopsis:

        <Data "voltage-input-1">
          RegisterBase 0
          RegisterType float
          RegisterCmd ReadHolding
          Type voltage
          Instance "input-1"
        </Data>

        <Data "voltage-input-2">
          RegisterBase 2
          RegisterType float
          RegisterCmd ReadHolding
          Type voltage
          Instance "input-2"
        </Data>

        <Data "supply-temperature-1">
          RegisterBase 0
          RegisterType Int16
          RegisterCmd ReadHolding
          Type temperature
          Instance "temp-1"
        </Data>

        <Host "modbus.example.com">
          Address "192.168.0.42"
          Port    "502"
          Interval 60

          <Slave 1>
            Instance "power-supply"
            Collect  "voltage-input-1"
            Collect  "voltage-input-2"
          </Slave>
        </Host>

        <Host "localhost">
          Device "/dev/ttyUSB0"
          Baudrate 38400
          Interval 20

          <Slave 1>
            Instance "temperature"
            Collect  "supply-temperature-1"
          </Slave>
        </Host>

       <Data Name> blocks
           Data blocks define a mapping between register numbers and the "types" used by collectd.

           Within <Data /> blocks, the following options are allowed:

           RegisterBase Number
               Configures the base register to read from the device. If the option RegisterType has been set to
               Uint32 or Float, this and the next register will be read (the register number is increased by
               one).

           RegisterType Int16|Int32|Uint16|Uint32|Float
               Specifies what kind of data is returned by the device. If the type is Int32, Uint32 or Float, two
               16 bit registers will be read and the data is combined into one value. Defaults to Uint16.

           RegisterCmd ReadHolding|ReadInput
               Specifies register type to be collected from device. Works only with libmodbus 2.9.2 or higher.
               Defaults to ReadHolding.

           Type Type
               Specifies the "type" (data set) to use when dispatching the value to collectd. Currently, only
               data sets with exactly one data source are supported.

           Instance Instance
               Sets the type instance to use when dispatching the value to collectd. If unset, an empty string
               (no type instance) is used.

       <Host Name> blocks
           Host blocks are used to specify to which hosts to connect and what data to read from their "slaves".
           The string argument Name is used as hostname when dispatching the values to collectd.

           Within <Host /> blocks, the following options are allowed:

           Address Hostname
               For Modbus/TCP, specifies the node name (the actual network address) used to connect to the host.
               This may be an IP address or a hostname. Please note that the used libmodbus library only
               supports IPv4 at the moment.

           Port Service
               for Modbus/TCP, specifies the port used to connect to the host. The port can either be given as a
               number or as a service name. Please note that the Service argument must be a string, even if
               ports are given in their numerical form. Defaults to "502".

           Device Devicenode
               For Modbus/RTU, specifies the path to the serial device being used.

           Baudrate Baudrate
               For Modbus/RTU, specifies the baud rate of the serial device.  Note, connections currently
               support only 8/N/1.

           Interval Interval
               Sets the interval (in seconds) in which the values will be collected from this host. By default
               the global Interval setting will be used.

           <Slave ID>
               Over each connection, multiple Modbus devices may be reached. The slave ID is used to specify
               which device should be addressed. For each device you want to query, one Slave block must be
               given.

               Within <Slave /> blocks, the following options are allowed:

               Instance Instance
                   Specify the plugin instance to use when dispatching the values to collectd.  By default
                   "slave_ID" is used.

               Collect DataName
                   Specifies which data to retrieve from the device. DataName must be the same string as the
                   Name argument passed to a Data block. You can specify this option multiple times to collect
                   more than one value from a slave. At least one Collect option is mandatory.

   Plugin "mqtt"
       The MQTT plugin can send metrics to MQTT (Publish blocks) and receive values from MQTT (Subscribe
       blocks).

       Synopsis:

        <Plugin mqtt>
          <Publish "name">
            Host "mqtt.example.com"
            Prefix "collectd"
          </Publish>
          <Subscribe "name">
            Host "mqtt.example.com"
            Topic "collectd/#"
          </Subscribe>
        </Plugin>

       The plugin's configuration is in Publish and/or Subscribe blocks, configuring the sending and receiving
       direction respectively. The plugin will register a write callback named "mqtt/name" where name is the
       string argument given to the Publish block. Both types of blocks share many but not all of the following
       options. If an option is valid in only one of the blocks, it will be mentioned explicitly.

       Options:

       Host Hostname
           Hostname of the MQTT broker to connect to.

       Port Service
           Port number or service name of the MQTT broker to connect to.

       User UserName
           Username used when authenticating to the MQTT broker.

       Password Password
           Password used when authenticating to the MQTT broker.

       ClientId ClientId
           MQTT client ID to use. Defaults to the hostname used by collectd.

       QoS [0-2]
           Sets the Quality of Service, with the values 0, 1 and 2 meaning:

           0   At most once

           1   At least once

           2   Exactly once

           In Publish blocks, this option determines the QoS flag set on outgoing messages and defaults to 0. In
           Subscribe blocks, determines the maximum QoS setting the client is going to accept and defaults to 2.
           If the QoS flag on a message is larger than the maximum accepted QoS of a subscriber, the message's
           QoS will be downgraded.

       Prefix Prefix (Publish only)
           This plugin will use one topic per value list which will looks like a path.  Prefix is used as the
           first path element and defaults to collectd.

           An example topic name would be:

            collectd/cpu-0/cpu-user

       Retain false|true (Publish only)
           Controls whether the MQTT broker will retain (keep a copy of) the last message sent to each topic and
           deliver it to new subscribers. Defaults to false.

       StoreRates true|false (Publish only)
           Controls whether "DERIVE" and "COUNTER" metrics are converted to a rate before sending. Defaults to
           true.

       CleanSession true|false (Subscribe only)
           Controls whether the MQTT "cleans" the session up after the subscriber disconnects or if it maintains
           the subscriber's subscriptions and all messages that arrive while the subscriber is disconnected.
           Defaults to true.

       Topic TopicName (Subscribe only)
           Configures the topic(s) to subscribe to. You can use the single level "+" and multi level "#"
           wildcards. Defaults to collectd/#, i.e. all topics beneath the collectd branch.

       CACert file
           Path to the PEM-encoded CA certificate file. Setting this option enables TLS communication with the
           MQTT broker, and as such, Port should be the TLS-enabled port of the MQTT broker.  A valid TLS
           configuration requires CACert, CertificateFile and CertificateKeyFile.

       CertificateFile file
           Path to the PEM-encoded certificate file to use as client certificate when connecting to the MQTT
           broker.  A valid TLS configuration requires CACert, CertificateFile and CertificateKeyFile.

       CertificateKeyFile file
           Path to the unencrypted PEM-encoded key file corresponding to CertificateFile.  A valid TLS
           configuration requires CACert, CertificateFile and CertificateKeyFile.

       TLSProtocol protocol
           If configured, this specifies the string protocol version (e.g. "tlsv1", "tlsv1.2") to use for the
           TLS connection to the broker. If not set a default version is used which depends on the version of
           OpenSSL the Mosquitto library was linked against.

       CipherSuite ciphersuite
           A string describing the ciphers available for use. See ciphers(1) and the "openssl ciphers" utility
           for more information. If unset, the default ciphers will be used.

   Plugin "mysql"
       The "mysql plugin" requires mysqlclient to be installed. It connects to one or more databases when
       started and keeps the connection up as long as possible. When the connection is interrupted for whatever
       reason it will try to re-connect. The plugin will complain loudly in case anything goes wrong.

       This plugin issues the MySQL "SHOW STATUS" / "SHOW GLOBAL STATUS" command and collects information about
       MySQL network traffic, executed statements, requests, the query cache and threads by evaluating the
       "Bytes_{received,sent}", "Com_*", "Handler_*", "Qcache_*" and "Threads_*" return values. Please refer to
       the MySQL reference manual, 5.1.6. Server Status Variables for an explanation of these values.

       Optionally, master and slave statistics may be collected in a MySQL replication setup. In that case,
       information about the synchronization state of the nodes are collected by evaluating the "Position"
       return value of the "SHOW MASTER STATUS" command and the "Seconds_Behind_Master", "Read_Master_Log_Pos"
       and "Exec_Master_Log_Pos" return values of the "SHOW SLAVE STATUS" command. See the MySQL reference
       manual, 12.5.5.21 SHOW MASTER STATUS Syntax and 12.5.5.31 SHOW SLAVE STATUS Syntax for details.

       Synopsis:

         <Plugin mysql>
           <Database foo>
             Host "hostname"
             User "username"
             Password "password"
             Port "3306"
             MasterStats true
             ConnectTimeout 10
             SSLKey "/path/to/key.pem"
             SSLCert "/path/to/cert.pem"
             SSLCA "/path/to/ca.pem"
             SSLCAPath "/path/to/cas/"
             SSLCipher "DHE-RSA-AES256-SHA"
           </Database>

           <Database bar>
             Alias "squeeze"
             Host "localhost"
             Socket "/var/run/mysql/mysqld.sock"
             SlaveStats true
             SlaveNotifications true
           </Database>

          <Database galera>
             Alias "galera"
             Host "localhost"
             Socket "/var/run/mysql/mysqld.sock"
             WsrepStats true
          </Database>
         </Plugin>

       A Database block defines one connection to a MySQL database. It accepts a single argument which specifies
       the name of the database. None of the other options are required. MySQL will use default values as
       documented in the "mysql_real_connect()" and "mysql_ssl_set()" sections in the MySQL reference manual.

       Alias Alias
           Alias to use as sender instead of hostname when reporting. This may be useful when having cryptic
           hostnames.

       Host Hostname
           Hostname of the database server. Defaults to localhost.

       User Username
           Username to use when connecting to the database. The user does not have to be granted any privileges
           (which is synonym to granting the "USAGE" privilege), unless you want to collectd replication
           statistics (see MasterStats and SlaveStats below). In this case, the user needs the "REPLICATION
           CLIENT" (or "SUPER") privileges. Else, any existing MySQL user will do.

       Password Password
           Password needed to log into the database.

       Database Database
           Select this database. Defaults to no database which is a perfectly reasonable option for what this
           plugin does.

       Port Port
           TCP-port to connect to. The port must be specified in its numeric form, but it must be passed as a
           string nonetheless. For example:

             Port "3306"

           If Host is set to localhost (the default), this setting has no effect.  See the documentation for the
           "mysql_real_connect" function for details.

       Socket Socket
           Specifies the path to the UNIX domain socket of the MySQL server. This option only has any effect, if
           Host is set to localhost (the default).  Otherwise, use the Port option above. See the documentation
           for the "mysql_real_connect" function for details.

       InnodbStats true|false
           If enabled, metrics about the InnoDB storage engine are collected.  Disabled by default.

       MasterStats true|false
       SlaveStats true|false
           Enable the collection of master / slave statistics in a replication setup. In order to be able to get
           access to these statistics, the user needs special privileges. See the User documentation above.
           Defaults to false.

       SlaveNotifications true|false
           If enabled, the plugin sends a notification if the replication slave I/O and / or SQL threads are not
           running. Defaults to false.

       WsrepStats true|false
            Enable the collection of wsrep plugin statistics, used in Master-Master
            replication setups like in MySQL Galera/Percona XtraDB Cluster.
            User needs only privileges to execute 'SHOW GLOBAL STATUS'

       ConnectTimeout Seconds
           Sets the connect timeout for the MySQL client.

       SSLKey Path
           If provided, the X509 key in PEM format.

       SSLCert Path
           If provided, the X509 cert in PEM format.

       SSLCA Path
           If provided, the CA file in PEM format (check OpenSSL docs).

       SSLCAPath Path
           If provided, the CA directory (check OpenSSL docs).

       SSLCipher String
           If provided, the SSL cipher to use.

   Plugin "netapp"
       The netapp plugin can collect various performance and capacity information from a NetApp filer using the
       NetApp API.

       Please note that NetApp has a wide line of products and a lot of different software versions for each of
       these products. This plugin was developed for a NetApp FAS3040 running OnTap 7.2.3P8 and tested on
       FAS2050 7.3.1.1L1, FAS3140 7.2.5.1 and FAS3020 7.2.4P9. It should work for most combinations of model and
       software version but it is very hard to test this.  If you have used this plugin with other models and/or
       software version, feel free to send us a mail to tell us about the results, even if it's just a short "It
       works".

       To collect these data collectd will log in to the NetApp via HTTP(S) and HTTP basic authentication.

       Do not use a regular user for this! Create a special collectd user with just the minimum of capabilities
       needed. The user only needs the "login-http-admin" capability as well as a few more depending on which
       data will be collected.  Required capabilities are documented below.

       Synopsis

        <Plugin "netapp">
          <Host "netapp1.example.com">
           Protocol      "https"
           Address       "10.0.0.1"
           Port          443
           User          "username"
           Password      "aef4Aebe"
           Interval      30

           <WAFL>
             Interval 30
             GetNameCache   true
             GetDirCache    true
             GetBufferCache true
             GetInodeCache  true
           </WAFL>

           <Disks>
             Interval 30
             GetBusy true
           </Disks>

           <VolumePerf>
             Interval 30
             GetIO      "volume0"
             IgnoreSelectedIO      false
             GetOps     "volume0"
             IgnoreSelectedOps     false
             GetLatency "volume0"
             IgnoreSelectedLatency false
           </VolumePerf>

           <VolumeUsage>
             Interval 30
             GetCapacity "vol0"
             GetCapacity "vol1"
             IgnoreSelectedCapacity false
             GetSnapshot "vol1"
             GetSnapshot "vol3"
             IgnoreSelectedSnapshot false
           </VolumeUsage>

           <Quota>
             Interval 60
           </Quota>

           <Snapvault>
             Interval 30
           </Snapvault>

           <System>
             Interval 30
             GetCPULoad     true
             GetInterfaces  true
             GetDiskOps     true
             GetDiskIO      true
           </System>

           <VFiler vfilerA>
             Interval 60

             SnapVault true
             # ...
           </VFiler>
          </Host>
        </Plugin>

       The netapp plugin accepts the following configuration options:

       Host Name
           A host block defines one NetApp filer. It will appear in collectd with the name you specify here
           which does not have to be its real name nor its hostname (see the Address option below).

       VFiler Name
           A VFiler block may only be used inside a host block. It accepts all the same options as the Host
           block (except for cascaded VFiler blocks) and will execute all NetApp API commands in the context of
           the specified VFiler(R). It will appear in collectd with the name you specify here which does not
           have to be its real name. The VFiler name may be specified using the VFilerName option. If this is
           not specified, it will default to the name you specify here.

           The VFiler block inherits all connection related settings from the surrounding Host block (which
           appear before the VFiler block) but they may be overwritten inside the VFiler block.

           This feature is useful, for example, when using a VFiler as SnapVault target (supported since OnTap
           8.1). In that case, the SnapVault statistics are not available in the host filer (vfiler0) but only
           in the respective VFiler context.

       Protocol httpd|http
           The protocol collectd will use to query this host.

           Optional

           Type: string

           Default: https

           Valid options: http, https

       Address Address
           The hostname or IP address of the host.

           Optional

           Type: string

           Default: The "host" block's name.

       Port Port
           The TCP port to connect to on the host.

           Optional

           Type: integer

           Default: 80 for protocol "http", 443 for protocol "https"

       User User
       Password Password
           The username and password to use to login to the NetApp.

           Mandatory

           Type: string

       VFilerName Name
           The name of the VFiler in which context to execute API commands. If not specified, the name provided
           to the VFiler block will be used instead.

           Optional

           Type: string

           Default: name of the VFiler block

           Note: This option may only be used inside VFiler blocks.

       Interval Interval
           TODO

       The following options decide what kind of data will be collected. You can either use them as a block and
       fine tune various parameters inside this block, use them as a single statement to just accept all default
       values, or omit it to not collect any data.

       The following options are valid inside all blocks:

       Interval Seconds
           Collect the respective statistics every Seconds seconds. Defaults to the host specific setting.

       The System block

       This will collect various performance data about the whole system.

       Note: To get this data the collectd user needs the "api-perf-object-get-instances" capability.

       Interval Seconds
           Collect disk statistics every Seconds seconds.

       GetCPULoad true|false
           If you set this option to true the current CPU usage will be read. This will be the average usage
           between all CPUs in your NetApp without any information about individual CPUs.

           Note: These are the same values that the NetApp CLI command "sysstat" returns in the "CPU" field.

           Optional

           Type: boolean

           Default: true

           Result: Two value lists of type "cpu", and type instances "idle" and "system".

       GetInterfaces true|false
           If you set this option to true the current traffic of the network interfaces will be read. This will
           be the total traffic over all interfaces of your NetApp without any information about individual
           interfaces.

           Note: This is the same values that the NetApp CLI command "sysstat" returns in the "Net kB/s" field.

           Or is it?

           Optional

           Type: boolean

           Default: true

           Result: One value list of type "if_octects".

       GetDiskIO true|false
           If you set this option to true the current IO throughput will be read. This will be the total IO of
           your NetApp without any information about individual disks, volumes or aggregates.

           Note: This is the same values that the NetApp CLI command "sysstat" returns in the "Disk kB/s" field.

           Optional

           Type: boolean

           Default: true

           Result: One value list of type "disk_octets".

       GetDiskOps true|false
           If you set this option to true the current number of HTTP, NFS, CIFS, FCP, iSCSI, etc. operations
           will be read. This will be the total number of operations on your NetApp without any information
           about individual volumes or aggregates.

           Note: These are the same values that the NetApp CLI command "sysstat" returns in the "NFS", "CIFS",
           "HTTP", "FCP" and "iSCSI" fields.

           Optional

           Type: boolean

           Default: true

           Result: A variable number of value lists of type "disk_ops_complex". Each type of operation will
           result in one value list with the name of the operation as type instance.

       The WAFL block

       This will collect various performance data about the WAFL file system. At the moment this just means
       cache performance.

       Note: To get this data the collectd user needs the "api-perf-object-get-instances" capability.

       Note: The interface to get these values is classified as "Diagnostics" by NetApp. This means that it is
       not guaranteed to be stable even between minor releases.

       Interval Seconds
           Collect disk statistics every Seconds seconds.

       GetNameCache true|false
           Optional

           Type: boolean

           Default: true

           Result: One value list of type "cache_ratio" and type instance "name_cache_hit".

       GetDirCache true|false
           Optional

           Type: boolean

           Default: true

           Result: One value list of type "cache_ratio" and type instance "find_dir_hit".

       GetInodeCache true|false
           Optional

           Type: boolean

           Default: true

           Result: One value list of type "cache_ratio" and type instance "inode_cache_hit".

       GetBufferCache true|false
           Note: This is the same value that the NetApp CLI command "sysstat" returns in the "Cache hit" field.

           Optional

           Type: boolean

           Default: true

           Result: One value list of type "cache_ratio" and type instance "buf_hash_hit".

       The Disks block

       This will collect performance data about the individual disks in the NetApp.

       Note: To get this data the collectd user needs the "api-perf-object-get-instances" capability.

       Interval Seconds
           Collect disk statistics every Seconds seconds.

       GetBusy true|false
           If you set this option to true the busy time of all disks will be calculated and the value of the
           busiest disk in the system will be written.

           Note: This is the same values that the NetApp CLI command "sysstat" returns in the "Disk util" field.
           Probably.

           Optional

           Type: boolean

           Default: true

           Result: One value list of type "percent" and type instance "disk_busy".

       The VolumePerf block

       This will collect various performance data about the individual volumes.

       You can select which data to collect about which volume using the following options. They follow the
       standard ignorelist semantic.

       Note: To get this data the collectd user needs the api-perf-object-get-instances capability.

       Interval Seconds
           Collect volume performance data every Seconds seconds.

       GetIO Volume
       GetOps Volume
       GetLatency Volume
           Select the given volume for IO, operations or latency statistics collection.  The argument is the
           name of the volume without the "/vol/" prefix.

           Since the standard ignorelist functionality is used here, you can use a string starting and ending
           with a slash to specify regular expression matching: To match the volumes "vol0", "vol2" and "vol7",
           you can use this regular expression:

             GetIO "/^vol[027]$/"

           If no regular expression is specified, an exact match is required. Both, regular and exact matching
           are case sensitive.

           If no volume was specified at all for either of the three options, that data will be collected for
           all available volumes.

           See /"IGNORELISTS" for details.

       IgnoreSelectedIO true|false
       IgnoreSelectedOps true|false
       IgnoreSelectedLatency true|false
           When set to true, the volumes selected for IO, operations or latency statistics collection will be
           ignored and the data will be collected for all other volumes.

           When set to false, data will only be collected for the specified volumes and all other volumes will
           be ignored.

           If no volumes have been specified with the above Get* options, all volumes will be collected
           regardless of the IgnoreSelected* option.

           Defaults to false

       The VolumeUsage block

       This will collect capacity data about the individual volumes.

       Note: To get this data the collectd user needs the api-volume-list-info capability.

       Interval Seconds
           Collect volume usage statistics every Seconds seconds.

       GetCapacity VolumeName
           The current capacity of the volume will be collected. This will result in two to four value lists,
           depending on the configuration of the volume. All data sources are of type "df_complex" with the name
           of the volume as plugin_instance.

           There will be type_instances "used" and "free" for the number of used and available bytes on the
           volume.  If the volume has some space reserved for snapshots, a type_instance "snap_reserved" will be
           available.  If the volume has SIS enabled, a type_instance "sis_saved" will be available. This is the
           number of bytes saved by the SIS feature.

           Note: The current NetApp API has a bug that results in this value being reported as a 32 bit number.
           This plugin tries to guess the correct number which works most of the time.  If you see strange
           values here, bug NetApp support to fix this.

           Repeat this option to specify multiple volumes.

       IgnoreSelectedCapacity true|false
           Specify whether to collect only the volumes selected by the GetCapacity option or to ignore those
           volumes. IgnoreSelectedCapacity defaults to false. However, if no GetCapacity option is specified at
           all, all capacities will be selected anyway.

       GetSnapshot VolumeName
           Select volumes from which to collect snapshot information.

           Usually, the space used for snapshots is included in the space reported as "used". If snapshot
           information is collected as well, the space used for snapshots is subtracted from the used space.

           To make things even more interesting, it is possible to reserve space to be used for snapshots. If
           the space required for snapshots is less than that reserved space, there is "reserved free" and
           "reserved used" space in addition to "free" and "used". If the space required for snapshots exceeds
           the reserved space, that part allocated in the normal space is subtracted from the "used" space
           again.

           Repeat this option to specify multiple volumes.

       IgnoreSelectedSnapshot
           Specify whether to collect only the volumes selected by the GetSnapshot option or to ignore those
           volumes. IgnoreSelectedSnapshot defaults to false. However, if no GetSnapshot option is specified at
           all, all capacities will be selected anyway.

       The Quota block

       This will collect (tree) quota statistics (used disk space and number of used files). This mechanism is
       useful to get usage information for single qtrees.  In case the quotas are not used for any other
       purpose, an entry similar to the following in "/etc/quotas" would be sufficient:

         /vol/volA/some_qtree tree - - - - -

       After adding the entry, issue "quota on -w volA" on the NetApp filer.

       Interval Seconds
           Collect SnapVault(R) statistics every Seconds seconds.

       The SnapVault block

       This will collect statistics about the time and traffic of SnapVault(R) transfers.

       Interval Seconds
           Collect SnapVault(R) statistics every Seconds seconds.

   Plugin "netlink"
       The "netlink" plugin uses a netlink socket to query the Linux kernel about statistics of various
       interface and routing aspects.

       Interface Interface
       VerboseInterface Interface
           Instruct the plugin to collect interface statistics. This is basically the same as the statistics
           provided by the "interface" plugin (see above) but potentially much more detailed.

           When configuring with Interface only the basic statistics will be collected, namely octets, packets,
           and errors. These statistics are collected by the "interface" plugin, too, so using both at the same
           time is no benefit.

           When configured with VerboseInterface all counters except the basic ones, so that no data needs to be
           collected twice if you use the "interface" plugin.  This includes dropped packets, received multicast
           packets, collisions and a whole zoo of differentiated RX and TX errors. You can try the following
           command to get an idea of what awaits you:

             ip -s -s link list

           If Interface is All, all interfaces will be selected.

       QDisc Interface [QDisc]
       Class Interface [Class]
       Filter Interface [Filter]
           Collect the octets and packets that pass a certain qdisc, class or filter.

           QDiscs and classes are identified by their type and handle (or classid).  Filters don't necessarily
           have a handle, therefore the parent's handle is used.  The notation used in collectd differs from
           that used in tc(1) in that it doesn't skip the major or minor number if it's zero and doesn't print
           special ids by their name. So, for example, a qdisc may be identified by "pfifo_fast-1:0" even though
           the minor number of all qdiscs is zero and thus not displayed by tc(1).

           If QDisc, Class, or Filter is given without the second argument, i. .e. without an identifier, all
           qdiscs, classes, or filters that are associated with that interface will be collected.

           Since a filter itself doesn't necessarily have a handle, the parent's handle is used. This may lead
           to problems when more than one filter is attached to a qdisc or class. This isn't nice, but we don't
           know how this could be done any better. If you have a idea, please don't hesitate to tell us.

           As with the Interface option you can specify All as the interface, meaning all interfaces.

           Here are some examples to help you understand the above text more easily:

             <Plugin netlink>
               VerboseInterface "All"
               QDisc "eth0" "pfifo_fast-1:0"
               QDisc "ppp0"
               Class "ppp0" "htb-1:10"
               Filter "ppp0" "u32-1:0"
             </Plugin>

           See /"IGNORELISTS" for details.

       IgnoreSelected
           The behavior is the same as with all other similar plugins: If nothing is selected at all, everything
           is collected. If some things are selected using the options described above, only these statistics
           are collected. If you set IgnoreSelected to true, this behavior is inverted, i. e. the specified
           statistics will not be collected.

   Plugin "network"
       The Network plugin sends data to a remote instance of collectd, receives data from a remote instance, or
       both at the same time. Data which has been received from the network is usually not transmitted again,
       but this can be activated, see the Forward option below.

       The default IPv6 multicast group is "ff18::efc0:4a42". The default IPv4 multicast group is 239.192.74.66.
       The default UDP port is 25826.

       Both, Server and Listen can be used as single option or as block. When used as block, given options are
       valid for this socket only. The following example will export the metrics twice: Once to an "internal"
       server (without encryption and signing) and one to an external server (with cryptographic signature):

        <Plugin "network">
          # Export to an internal server
          # (demonstrates usage without additional options)
          Server "collectd.internal.tld"

          # Export to an external server
          # (demonstrates usage with signature options)
          <Server "collectd.external.tld">
            SecurityLevel "sign"
            Username "myhostname"
            Password "ohl0eQue"
          </Server>
        </Plugin>

       <Server Host [Port]>
           The Server statement/block sets the server to send datagrams to. The statement may occur multiple
           times to send each datagram to multiple destinations.

           The argument Host may be a hostname, an IPv4 address or an IPv6 address. The optional second argument
           specifies a port number or a service name. If not given, the default, 25826, is used.

           The following options are recognized within Server blocks:

           SecurityLevel Encrypt|Sign|None
               Set the security you require for network communication. When the security level has been set to
               Encrypt, data sent over the network will be encrypted using AES-256. The integrity of encrypted
               packets is ensured using SHA-1. When set to Sign, transmitted data is signed using the
               HMAC-SHA-256 message authentication code. When set to None, data is sent without any security.

               This feature is only available if the network plugin was linked with libgcrypt.

           Username Username
               Sets the username to transmit. This is used by the server to lookup the password. See AuthFile
               below. All security levels except None require this setting.

               This feature is only available if the network plugin was linked with libgcrypt.

           Password Password
               Sets a password (shared secret) for this socket. All security levels except None require this
               setting.

               This feature is only available if the network plugin was linked with libgcrypt.

           Interface Interface name
               Set the outgoing interface for IP packets. This applies at least to IPv6 packets and if possible
               to IPv4. If this option is not applicable, undefined or a non-existent interface name is
               specified, the default behavior is to let the kernel choose the appropriate interface. Be warned
               that the manual selection of an interface for unicast traffic is only necessary in rare cases.

           ResolveInterval Seconds
               Sets the interval at which to re-resolve the DNS for the Host. This is useful to force a regular
               DNS lookup to support a high availability setup. If not specified, re-resolves are never
               attempted.

       <Listen Host [Port]>
           The Listen statement sets the interfaces to bind to. When multiple statements are found the daemon
           will bind to multiple interfaces.

           The argument Host may be a hostname, an IPv4 address or an IPv6 address. If the argument is a
           multicast address the daemon will join that multicast group.  The optional second argument specifies
           a port number or a service name. If not given, the default, 25826, is used.

           The following options are recognized within "<Listen>" blocks:

           SecurityLevel Encrypt|Sign|None
               Set the security you require for network communication. When the security level has been set to
               Encrypt, only encrypted data will be accepted. The integrity of encrypted packets is ensured
               using SHA-1. When set to Sign, only signed and encrypted data is accepted. When set to None, all
               data will be accepted. If an AuthFile option was given (see below), encrypted data is decrypted
               if possible.

               This feature is only available if the network plugin was linked with libgcrypt.

           AuthFile Filename
               Sets a file in which usernames are mapped to passwords. These passwords are used to verify
               signatures and to decrypt encrypted network packets. If SecurityLevel is set to None, this is
               optional. If given, signed data is verified and encrypted packets are decrypted. Otherwise,
               signed data is accepted without checking the signature and encrypted data cannot be decrypted.
               For the other security levels this option is mandatory.

               The file format is very simple: Each line consists of a username followed by a colon and any
               number of spaces followed by the password. To demonstrate, an example file could look like this:

                 user0: foo
                 user1: bar

               Each time a packet is received, the modification time of the file is checked using stat(2). If
               the file has been changed, the contents is re-read. While the file is being read, it is locked
               using fcntl(2).

           Interface Interface name
               Set the incoming interface for IP packets explicitly. This applies at least to IPv6 packets and
               if possible to IPv4. If this option is not applicable, undefined or a non-existent interface name
               is specified, the default behavior is, to let the kernel choose the appropriate interface. Thus
               incoming traffic gets only accepted, if it arrives on the given interface.

       TimeToLive 1-255
           Set the time-to-live of sent packets. This applies to all, unicast and multicast, and IPv4 and IPv6
           packets. The default is to not change this value.  That means that multicast packets will be sent
           with a TTL of 1 (one) on most operating systems.

       MaxPacketSize 1024-65535
           Set the maximum size for datagrams received over the network. Packets larger than this will be
           truncated. Defaults to 1452 bytes, which is the maximum payload size that can be transmitted in one
           Ethernet frame using IPv6 / UDP.

           On the server side, this limit should be set to the largest value used on any client. Likewise, the
           value on the client must not be larger than the value on the server, or data will be lost.

           Compatibility: Versions prior to version 4.8 used a fixed sized buffer of 1024 bytes. Versions 4.8,
           4.9 and 4.10 used a default value of 1024 bytes to avoid problems when sending data to an older
           server.

       Forward true|false
           If set to true, write packets that were received via the network plugin to the sending sockets. This
           should only be activated when the Listen- and Server-statements differ. Otherwise packets may be send
           multiple times to the same multicast group. While this results in more network traffic than necessary
           it's not a huge problem since the plugin has a duplicate detection, so the values will not loop.

       ReportStats true|false
           The network plugin cannot only receive and send statistics, it can also create statistics about
           itself. Collectd data included the number of received and sent octets and packets, the length of the
           receive queue and the number of values handled. When set to true, the Network plugin will make these
           statistics available. Defaults to false.

   Plugin "nginx"
       This plugin collects the number of connections and requests handled by the "nginx daemon" (speak:
       engine X), a HTTP and mail server/proxy. It queries the page provided by the
       "ngx_http_stub_status_module" module, which isn't compiled by default. Please refer to
       <http://wiki.codemongers.com/NginxStubStatusModule> for more information on how to compile and configure
       nginx and this module.

       The following options are accepted by the "nginx plugin":

       URL http://host/nginx_status
           Sets the URL of the "ngx_http_stub_status_module" output.

       User Username
           Optional user name needed for authentication.

       Password Password
           Optional password needed for authentication.

       VerifyPeer true|false
           Enable or disable peer SSL certificate verification. See <http://curl.haxx.se/docs/sslcerts.html> for
           details. Enabled by default.

       VerifyHost true|false
           Enable or disable peer host name verification. If enabled, the plugin checks if the "Common Name" or
           a "Subject Alternate Name" field of the SSL certificate matches the host name provided by the URL
           option. If this identity check fails, the connection is aborted. Obviously, only works when
           connecting to a SSL enabled server. Enabled by default.

       CACert File
           File that holds one or more SSL certificates. If you want to use HTTPS you will possibly need this
           option. What CA certificates come bundled with "libcurl" and are checked by default depends on the
           distribution you use.

       Timeout Milliseconds
           The Timeout option sets the overall timeout for HTTP requests to URL, in milliseconds. By default,
           the configured Interval is used to set the timeout.

   Plugin "notify_desktop"
       This plugin sends a desktop notification to a notification daemon, as defined in the Desktop Notification
       Specification. To actually display the notifications, notification-daemon is required and collectd has to
       be able to access the X server (i. e., the "DISPLAY" and "XAUTHORITY" environment variables have to be
       set correctly) and the D-Bus message bus.

       The Desktop Notification Specification can be found at
       <http://www.galago-project.org/specs/notification/>.

       OkayTimeout timeout
       WarningTimeout timeout
       FailureTimeout timeout
           Set the timeout, in milliseconds, after which to expire the notification for "OKAY", "WARNING" and
           "FAILURE" severities respectively. If zero has been specified, the displayed notification will not be
           closed at all - the user has to do so herself. These options default to 5000. If a negative number
           has been specified, the default is used as well.

   Plugin "notify_email"
       The notify_email plugin uses the ESMTP library to send notifications to a configured email address.

       libESMTP is available from <http://www.stafford.uklinux.net/libesmtp/>.

       Available configuration options:

       From Address
           Email address from which the emails should appear to come from.

           Default: "root@localhost"

       Recipient Address
           Configures the email address(es) to which the notifications should be mailed.  May be repeated to
           send notifications to multiple addresses.

           At least one Recipient must be present for the plugin to work correctly.

       SMTPServer Hostname
           Hostname of the SMTP server to connect to.

           Default: "localhost"

       SMTPPort Port
           TCP port to connect to.

           Default: 25

       SMTPUser Username
           Username for ASMTP authentication. Optional.

       SMTPPassword Password
           Password for ASMTP authentication. Optional.

       Subject Subject
           Subject-template to use when sending emails. There must be exactly two string-placeholders in the
           subject, given in the standard printf(3) syntax, i. e. %s. The first will be replaced with the
           severity, the second with the hostname.

           Default: "Collectd notify: %s@%s"

   Plugin "notify_nagios"
       The notify_nagios plugin writes notifications to Nagios' command file as a passive service check result.

       Available configuration options:

       CommandFile Path
           Sets the command file to write to. Defaults to /usr/local/nagios/var/rw/nagios.cmd.

   Plugin "ntpd"
       The "ntpd" plugin collects per-peer ntp data such as time offset and time dispersion.

       For talking to ntpd, it mimics what the ntpdc control program does on the wire - using mode 7 specific
       requests. This mode is deprecated with newer ntpd releases (4.2.7p230 and later). For the "ntpd" plugin
       to work correctly with them, the ntp daemon must be explicitly configured to enable mode 7 (which is
       disabled by default). Refer to the ntp.conf(5) manual page for details.

       Available configuration options for the "ntpd" plugin:

       Host Hostname
           Hostname of the host running ntpd. Defaults to localhost.

       Port Port
           UDP-Port to connect to. Defaults to 123.

       ReverseLookups true|false
           Sets whether or not to perform reverse lookups on peers. Since the name or IP-address may be used in
           a filename it is recommended to disable reverse lookups. The default is to do reverse lookups to
           preserve backwards compatibility, though.

       IncludeUnitID true|false
           When a peer is a refclock, include the unit ID in the type instance.  Defaults to false for backward
           compatibility.

           If two refclock peers use the same driver and this is false, the plugin will try to write
           simultaneous measurements from both to the same type instance.  This will result in error messages in
           the log and only one set of measurements making it through.

   Plugin "nut"
       UPS upsname@hostname[:port]
           Add a UPS to collect data from. The format is identical to the one accepted by upsc(8).

   Plugin "olsrd"
       The olsrd plugin connects to the TCP port opened by the txtinfo plugin of the Optimized Link State
       Routing daemon and reads information about the current state of the meshed network.

       The following configuration options are understood:

       Host Host
           Connect to Host. Defaults to "localhost".

       Port Port
           Specifies the port to connect to. This must be a string, even if you give the port as a number rather
           than a service name. Defaults to "2006".

       CollectLinks No|Summary|Detail
           Specifies what information to collect about links, i. e. direct connections of the daemon queried. If
           set to No, no information is collected. If set to Summary, the number of links and the average of all
           link quality (LQ) and neighbor link quality (NLQ) values is calculated.  If set to Detail LQ and NLQ
           are collected per link.

           Defaults to Detail.

       CollectRoutes No|Summary|Detail
           Specifies what information to collect about routes of the daemon queried. If set to No, no
           information is collected. If set to Summary, the number of routes and the average metric and ETX is
           calculated. If set to Detail metric and ETX are collected per route.

           Defaults to Summary.

       CollectTopology No|Summary|Detail
           Specifies what information to collect about the global topology. If set to No, no information is
           collected. If set to Summary, the number of links in the entire topology and the average link quality
           (LQ) is calculated.  If set to Detail LQ and NLQ are collected for each link in the entire topology.

           Defaults to Summary.

   Plugin "onewire"
       EXPERIMENTAL! See notes below.

       The "onewire" plugin uses the owcapi library from the owfs project <http://owfs.org/> to read sensors
       connected via the onewire bus.

       It can be used in two possible modes - standard or advanced.

       In the standard mode only temperature sensors (sensors with the family code 10, 22 and 28 - e.g. DS1820,
       DS18S20, DS1920) can be read. If you have other sensors you would like to have included, please send a
       sort request to the mailing list. You can select sensors to be read or to be ignored depending on the
       option IgnoreSelected). When no list is provided the whole bus is walked and all sensors are read.

       Hubs (the DS2409 chips) are working, but read the note, why this plugin is experimental, below.

       In the advanced mode you can configure any sensor to be read (only numerical value) using full OWFS path
       (e.g. "/uncached/10.F10FCA000800/temperature").  In this mode you have to list all the sensors. Neither
       default bus walk nor IgnoreSelected are used here. Address and type (file) is extracted from the path
       automatically and should produce compatible structure with the "standard" mode (basically the path is
       expected as for example "/uncached/10.F10FCA000800/temperature" where it would extract address part
       "F10FCA000800" and the rest after the slash is considered the type - here "temperature").  There are two
       advantages to this mode - you can access virtually any sensor (not just temperature), select whether to
       use cached or directly read values and it is slighlty faster. The downside is more complex configuration.

       The two modes are distinguished automatically by the format of the address.  It is not possible to mix
       the two modes. Once a full path is detected in any Sensor then the whole addressing (all sensors) is
       considered to be this way (and as standard addresses will fail parsing they will be ignored).

       Device Device
           Sets the device to read the values from. This can either be a "real" hardware device, such as a
           serial port or an USB port, or the address of the owserver(1) socket, usually localhost:4304.

           Though the documentation claims to automatically recognize the given address format, with
           version 2.7p4 we had to specify the type explicitly. So with that version, the following
           configuration worked for us:

             <Plugin onewire>
               Device "-s localhost:4304"
             </Plugin>

           This directive is required and does not have a default value.

       Sensor Sensor
           In the standard mode selects sensors to collect or to ignore (depending on IgnoreSelected, see
           below). Sensors are specified without the family byte at the beginning, so you have to use for
           example "F10FCA000800", and not include the leading 10. family byte and point.  When no Sensor is
           configured the whole Onewire bus is walked and all supported sensors (see above) are read.

           In the advanced mode the Sensor specifies full OWFS path - e.g.
           "/uncached/10.F10FCA000800/temperature" (or when cached values are OK
           "/10.F10FCA000800/temperature"). IgnoreSelected is not used.

           As there can be multiple devices on the bus you can list multiple sensor (use multiple Sensor
           elements).

           See /"IGNORELISTS" for details.

       IgnoreSelected true|false
           If no configuration is given, the onewire plugin will collect data from all sensors found. This may
           not be practical, especially if sensors are added and removed regularly. Sometimes, however, it's
           easier/preferred to collect only specific sensors or all sensors except a few specified ones. This
           option enables you to do that: By setting IgnoreSelected to true the effect of Sensor is inverted:
           All selected interfaces are ignored and all other interfaces are collected.

           Used only in the standard mode - see above.

       Interval Seconds
           Sets the interval in which all sensors should be read. If not specified, the global Interval setting
           is used.

       EXPERIMENTAL! The "onewire" plugin is experimental, because it doesn't yet work with big setups. It works
       with one sensor being attached to one controller, but as soon as you throw in a couple more senors and
       maybe a hub or two, reading all values will take more than ten seconds (the default interval). We will
       probably add some separate thread for reading the sensors and some cache or something like that, but it's
       not done yet. We will try to maintain backwards compatibility in the future, but we can't promise. So in
       short: If it works for you: Great! But keep in mind that the config might change, though this is
       unlikely. Oh, and if you want to help improving this plugin, just send a short notice to the mailing
       list. Thanks :)

   Plugin "openldap"
       To use the "openldap" plugin you first need to configure the OpenLDAP server correctly. The backend
       database "monitor" needs to be loaded and working. See slapd-monitor(5) for the details.

       The configuration of the "openldap" plugin consists of one or more Instance blocks. Each block requires
       one string argument as the instance name. For example:

        <Plugin "openldap">
          <Instance "foo">
            URL "ldap://localhost/"
          </Instance>
          <Instance "bar">
            URL "ldaps://localhost/"
          </Instance>
        </Plugin>

       The instance name will be used as the plugin instance. To emulate the old (version 4) behavior, you can
       use an empty string (""). In order for the plugin to work correctly, each instance name must be unique.
       This is not enforced by the plugin and it is your responsibility to ensure it is.

       The following options are accepted within each Instance block:

       URL ldap://host/binddn
           Sets the URL to use to connect to the OpenLDAP server. This option is mandatory.

       BindDN BindDN
           Name in the form of an LDAP distinguished name intended to be used for authentication. Defaults to
           empty string to establish an anonymous authorization.

       Password Password
           Password for simple bind authentication. If this option is not set, unauthenticated bind operation is
           used.

       StartTLS true|false
           Defines whether TLS must be used when connecting to the OpenLDAP server.  Disabled by default.

       VerifyHost true|false
           Enables or disables peer host name verification. If enabled, the plugin checks if the "Common Name"
           or a "Subject Alternate Name" field of the SSL certificate matches the host name provided by the URL
           option. If this identity check fails, the connection is aborted. Enabled by default.

       CACert File
           File that holds one or more SSL certificates. If you want to use TLS/SSL you may possibly need this
           option. What CA certificates are checked by default depends on the distribution you use and can be
           changed with the usual ldap client configuration mechanisms. See ldap.conf(5) for the details.

       Timeout Seconds
           Sets the timeout value for ldap operations, in seconds. By default, the configured Interval is used
           to set the timeout. Use -1 to disable (infinite timeout).

       Version Version
           An integer which sets the LDAP protocol version number to use when connecting to the OpenLDAP server.
           Defaults to 3 for using LDAPv3.

   Plugin "openvpn"
       The OpenVPN plugin reads a status file maintained by OpenVPN and gathers traffic statistics about
       connected clients.

       To set up OpenVPN to write to the status file periodically, use the --status option of OpenVPN. Since
       OpenVPN can write two different formats, you need to set the required format, too. This is done by
       setting --status-version to 2.

       So, in a nutshell you need:

         openvpn $OTHER_OPTIONS \
           --status "/var/run/openvpn-status" 10 \
           --status-version 2

       Available options:

       StatusFile File
           Specifies the location of the status file.

       ImprovedNamingSchema true|false
           When enabled, the filename of the status file will be used as plugin instance and the client's
           "common name" will be used as type instance. This is required when reading multiple status files.
           Enabling this option is recommended, but to maintain backwards compatibility this option is disabled
           by default.

       CollectCompression true|false
           Sets whether or not statistics about the compression used by OpenVPN should be collected. This
           information is only available in single mode. Enabled by default.

       CollectIndividualUsers true|false
           Sets whether or not traffic information is collected for each connected client individually. If set
           to false, currently no traffic data is collected at all because aggregating this data in a save
           manner is tricky. Defaults to true.

       CollectUserCount true|false
           When enabled, the number of currently connected clients or users is collected.  This is especially
           interesting when CollectIndividualUsers is disabled, but can be configured independently from that
           option. Defaults to false.

   Plugin "oracle"
       The "oracle" plugin uses the OracleX Call Interface (OCI) to connect to an OracleX Database and lets you
       execute SQL statements there. It is very similar to the "dbi" plugin, because it was written around the
       same time. See the "dbi" plugin's documentation above for details.

         <Plugin oracle>
           <Query "out_of_stock">
             Statement "SELECT category, COUNT(*) AS value FROM products WHERE in_stock = 0 GROUP BY category"
             <Result>
               Type "gauge"
               # InstancePrefix "foo"
               InstancesFrom "category"
               ValuesFrom "value"
             </Result>
           </Query>
           <Database "product_information">
             ConnectID "db01"
             Username "oracle"
             Password "secret"
             Query "out_of_stock"
           </Database>
         </Plugin>

       Query blocks

       The Query blocks are handled identically to the Query blocks of the "dbi" plugin. Please see its
       documentation above for details on how to specify queries.

       Database blocks

       Database blocks define a connection to a database and which queries should be sent to that database. Each
       database needs a "name" as string argument in the starting tag of the block. This name will be used as
       "PluginInstance" in the values submitted to the daemon. Other than that, that name is not used.

       ConnectID ID
           Defines the "database alias" or "service name" to connect to. Usually, these names are defined in the
           file named "$ORACLE_HOME/network/admin/tnsnames.ora".

       Host Host
           Hostname to use when dispatching values for this database. Defaults to using the global hostname of
           the collectd instance.

       Username Username
           Username used for authentication.

       Password Password
           Password used for authentication.

       Query QueryName
           Associates the query named QueryName with this database connection. The query needs to be defined
           before this statement, i. e. all query blocks you want to refer to must be placed above the database
           block you want to refer to them from.

   Plugin "perl"
       This plugin embeds a Perl-interpreter into collectd and provides an interface to collectd's plugin
       system. See collectd-perl(5) for its documentation.

   Plugin "pinba"
       The Pinba plugin receives profiling information from Pinba, an extension for the PHP interpreter. At the
       end of executing a script, i.e. after a PHP-based webpage has been delivered, the extension will send a
       UDP packet containing timing information, peak memory usage and so on. The plugin will wait for such
       packets, parse them and account the provided information, which is then dispatched to the daemon once per
       interval.

       Synopsis:

        <Plugin pinba>
          Address "::0"
          Port "30002"
          # Overall statistics for the website.
          <View "www-total">
            Server "www.example.com"
          </View>
          # Statistics for www-a only
          <View "www-a">
            Host "www-a.example.com"
            Server "www.example.com"
          </View>
          # Statistics for www-b only
          <View "www-b">
            Host "www-b.example.com"
            Server "www.example.com"
          </View>
        </Plugin>

       The plugin provides the following configuration options:

       Address Node
           Configures the address used to open a listening socket. By default, plugin will bind to the any
           address "::0".

       Port Service
           Configures the port (service) to bind to. By default the default Pinba port "30002" will be used. The
           option accepts service names in addition to port numbers and thus requires a string argument.

       <View Name> block
           The packets sent by the Pinba extension include the hostname of the server, the server name (the name
           of the virtual host) and the script that was executed.  Using View blocks it is possible to separate
           the data into multiple groups to get more meaningful statistics. Each packet is added to all matching
           groups, so that a packet may be accounted for more than once.

           Host Host
               Matches the hostname of the system the webserver / script is running on. This will contain the
               result of the gethostname(2) system call. If not configured, all hostnames will be accepted.

           Server Server
               Matches the name of the virtual host, i.e. the contents of the $_SERVER["SERVER_NAME"] variable
               when within PHP. If not configured, all server names will be accepted.

           Script Script
               Matches the name of the script name, i.e. the contents of the $_SERVER["SCRIPT_NAME"] variable
               when within PHP. If not configured, all script names will be accepted.

   Plugin "ping"
       The Ping plugin starts a new thread which sends ICMP "ping" packets to the configured hosts periodically
       and measures the network latency. Whenever the "read" function of the plugin is called, it submits the
       average latency, the standard deviation and the drop rate for each host.

       Available configuration options:

       Host IP-address
           Host to ping periodically. This option may be repeated several times to ping multiple hosts.

       Interval Seconds
           Sets the interval in which to send ICMP echo packets to the configured hosts.  This is not the
           interval in which metrics are read from the plugin but the interval in which the hosts are "pinged".
           Therefore, the setting here should be smaller than or equal to the global Interval setting.
           Fractional times, such as "1.24" are allowed.

           Default: 1.0

       Timeout Seconds
           Time to wait for a response from the host to which an ICMP packet had been sent. If a reply was not
           received after Seconds seconds, the host is assumed to be down or the packet to be dropped. This
           setting must be smaller than the Interval setting above for the plugin to work correctly. Fractional
           arguments are accepted.

           Default: 0.9

       TTL 0-255
           Sets the Time-To-Live of generated ICMP packets.

       Size size
           Sets the size of the data payload in ICMP packet to specified size (it will be filled with regular
           ASCII pattern). If not set, default 56 byte long string is used so that the packet size of an ICMPv4
           packet is exactly 64 bytes, similar to the behaviour of normal ping(1) command.

       SourceAddress host
           Sets the source address to use. host may either be a numerical network address or a network hostname.

       Device name
           Sets the outgoing network device to be used. name has to specify an interface name (e. g. "eth0").
           This might not be supported by all operating systems.

       MaxMissed Packets
           Trigger a DNS resolve after the host has not replied to Packets packets. This enables the use of
           dynamic DNS services (like dyndns.org) with the ping plugin.

           Default: -1 (disabled)

   Plugin "postgresql"
       The "postgresql" plugin queries statistics from PostgreSQL databases. It keeps a persistent connection to
       all configured databases and tries to reconnect if the connection has been interrupted. A database is
       configured by specifying a Database block as described below. The default statistics are collected from
       PostgreSQL's statistics collector which thus has to be enabled for this plugin to work correctly. This
       should usually be the case by default. See the section "The Statistics Collector" of the PostgreSQL
       Documentation for details.

       By specifying custom database queries using a Query block as described below, you may collect any data
       that is available from some PostgreSQL database. This way, you are able to access statistics of external
       daemons which are available in a PostgreSQL database or use future or special statistics provided by
       PostgreSQL without the need to upgrade your collectd installation.

       Starting with version 5.2, the "postgresql" plugin supports writing data to PostgreSQL databases as well.
       This has been implemented in a generic way. You need to specify an SQL statement which will then be
       executed by collectd in order to write the data (see below for details). The benefit of that approach is
       that there is no fixed database layout. Rather, the layout may be optimized for the current setup.

       The PostgreSQL Documentation manual can be found at <http://www.postgresql.org/docs/manuals/>.

         <Plugin postgresql>
           <Query magic>
             Statement "SELECT magic FROM wizard WHERE host = $1;"
             Param hostname
             <Result>
               Type gauge
               InstancePrefix "magic"
               ValuesFrom magic
             </Result>
           </Query>

           <Query rt36_tickets>
             Statement "SELECT COUNT(type) AS count, type \
                               FROM (SELECT CASE \
                                            WHEN resolved = 'epoch' THEN 'open' \
                                            ELSE 'resolved' END AS type \
                                            FROM tickets) type \
                               GROUP BY type;"
             <Result>
               Type counter
               InstancePrefix "rt36_tickets"
               InstancesFrom "type"
               ValuesFrom "count"
             </Result>
           </Query>

           <Writer sqlstore>
             Statement "SELECT collectd_insert($1, $2, $3, $4, $5, $6, $7, $8, $9);"
             StoreRates true
           </Writer>

           <Database foo>
             Host "hostname"
             Port "5432"
             User "username"
             Password "secret"
             SSLMode "prefer"
             KRBSrvName "kerberos_service_name"
             Query magic
           </Database>

           <Database bar>
             Interval 300
             Service "service_name"
             Query backend # predefined
             Query rt36_tickets
           </Database>

           <Database qux>
             # ...
             Writer sqlstore
             CommitInterval 10
           </Database>
         </Plugin>

       The Query block defines one database query which may later be used by a database definition. It accepts a
       single mandatory argument which specifies the name of the query. The names of all queries have to be
       unique (see the MinVersion and MaxVersion options below for an exception to this rule).

       In each Query block, there is one or more Result blocks. Multiple Result blocks may be used to extract
       multiple values from a single query.

       The following configuration options are available to define the query:

       Statement sql query statement
           Specify the sql query statement which the plugin should execute. The string may contain the tokens
           $1, $2, etc. which are used to reference the first, second, etc. parameter. The value of the
           parameters is specified by the Param configuration option - see below for details. To include a
           literal $ character followed by a number, surround it with single quotes (').

           Any SQL command which may return data (such as "SELECT" or "SHOW") is allowed. Note, however, that
           only a single command may be used. Semicolons are allowed as long as a single non-empty command has
           been specified only.

           The returned lines will be handled separately one after another.

       Param hostname|database|instance|username|interval
           Specify the parameters which should be passed to the SQL query. The parameters are referred to in the
           SQL query as $1, $2, etc. in the same order as they appear in the configuration file. The value of
           the parameter is determined depending on the value of the Param option as follows:

           hostname
               The configured hostname of the database connection. If a UNIX domain socket is used, the
               parameter expands to "localhost".

           database
               The name of the database of the current connection.

           instance
               The name of the database plugin instance. See the Instance option of the database specification
               below for details.

           username
               The username used to connect to the database.

           interval
               The interval with which this database is queried (as specified by the database specific or global
               Interval options).

           Please note that parameters are only supported by PostgreSQL's protocol version 3 and above which was
           introduced in version 7.4 of PostgreSQL.

       PluginInstanceFrom column
           Specify how to create the "PluginInstance" for reporting this query results.  Only one column is
           supported. You may concatenate fields and string values in the query statement to get the required
           results.

       MinVersion version
       MaxVersion version
           Specify the minimum or maximum version of PostgreSQL that this query should be used with. Some
           statistics might only be available with certain versions of PostgreSQL. This allows you to specify
           multiple queries with the same name but which apply to different versions, thus allowing you to use
           the same configuration in a heterogeneous environment.

           The version has to be specified as the concatenation of the major, minor and patch-level versions,
           each represented as two-decimal-digit numbers. For example, version 8.2.3 will become 80203.

       The Result block defines how to handle the values returned from the query.  It defines which column holds
       which value and how to dispatch that value to the daemon.

       Type type
           The type name to be used when dispatching the values. The type describes how to handle the data and
           where to store it. See types.db(5) for more details on types and their configuration. The number and
           type of values (as selected by the ValuesFrom option) has to match the type of the given name.

           This option is mandatory.

       InstancePrefix prefix
       InstancesFrom column0 [column1 ...]
           Specify how to create the "TypeInstance" for each data set (i. e. line).  InstancePrefix defines a
           static prefix that will be prepended to all type instances. InstancesFrom defines the column names
           whose values will be used to create the type instance. Multiple values will be joined together using
           the hyphen ("-") as separation character.

           The plugin itself does not check whether or not all built instances are different. It is your
           responsibility to assure that each is unique.

           Both options are optional. If none is specified, the type instance will be empty.

       ValuesFrom column0 [column1 ...]
           Names the columns whose content is used as the actual data for the data sets that are dispatched to
           the daemon. How many such columns you need is determined by the Type setting as explained above. If
           you specify too many or not enough columns, the plugin will complain about that and no data will be
           submitted to the daemon.

           The actual data type, as seen by PostgreSQL, is not that important as long as it represents numbers.
           The plugin will automatically cast the values to the right type if it know how to do that. For that,
           it uses the strtoll(3) and strtod(3) functions, so anything supported by those functions is supported
           by the plugin as well.

           This option is required inside a Result block and may be specified multiple times. If multiple
           ValuesFrom options are specified, the columns are read in the given order.

       The following predefined queries are available (the definitions can be found in the
       postgresql_default.conf file which, by default, is available at "prefix/share/collectd/"):

       backends
           This query collects the number of backends, i. e. the number of connected clients.

       transactions
           This query collects the numbers of committed and rolled-back transactions of the user tables.

       queries
           This query collects the numbers of various table modifications (i. e.  insertions, updates,
           deletions) of the user tables.

       query_plans
           This query collects the numbers of various table scans and returned tuples of the user tables.

       table_states
           This query collects the numbers of live and dead rows in the user tables.

       disk_io
           This query collects disk block access counts for user tables.

       disk_usage
           This query collects the on-disk size of the database in bytes.

       In addition, the following detailed queries are available by default. Please note that each of those
       queries collects information by table, thus, potentially producing a lot of data. For details see the
       description of the non-by_table queries above.

       queries_by_table
       query_plans_by_table
       table_states_by_table
       disk_io_by_table

       The Writer block defines a PostgreSQL writer backend. It accepts a single mandatory argument specifying
       the name of the writer. This will then be used in the Database specification in order to activate the
       writer instance. The names of all writers have to be unique. The following options may be specified:

       Statement sql statement
           This mandatory option specifies the SQL statement that will be executed for each submitted value. A
           single SQL statement is allowed only. Anything after the first semicolon will be ignored.

           Nine parameters will be passed to the statement and should be specified as tokens $1, $2, through $9
           in the statement string. The following values are made available through those parameters:

           $1  The timestamp of the queried value as an RFC 3339-formatted local time.

           $2  The hostname of the queried value.

           $3  The plugin name of the queried value.

           $4  The plugin instance of the queried value. This value may be NULL if there is no plugin instance.

           $5  The type of the queried value (cf. types.db(5)).

           $6  The type instance of the queried value. This value may be NULL if there is no type instance.

           $7  An array of names for the submitted values (i. e., the name of the data sources of the submitted
               value-list).

           $8  An array of types for the submitted values (i. e., the type of the data sources of the submitted
               value-list; "counter", "gauge", ...). Note, that if StoreRates is enabled (which is the default,
               see below), all types will be "gauge".

           $9  An array of the submitted values. The dimensions of the value name and value arrays match.

           In general, it is advisable to create and call a custom function in the PostgreSQL database for this
           purpose. Any procedural language supported by PostgreSQL will do (see chapter "Server Programming" in
           the PostgreSQL manual for details).

       StoreRates false|true
           If set to true (the default), convert counter values to rates. If set to false counter values are
           stored as is, i. e. as an increasing integer number.

       The Database block defines one PostgreSQL database for which to collect statistics. It accepts a single
       mandatory argument which specifies the database name. None of the other options are required. PostgreSQL
       will use default values as documented in the section "CONNECTING TO A DATABASE" in the psql(1) manpage.
       However, be aware that those defaults may be influenced by the user collectd is run as and special
       environment variables. See the manpage for details.

       Interval seconds
           Specify the interval with which the database should be queried. The default is to use the global
           Interval setting.

       CommitInterval seconds
           This option may be used for database connections which have "writers" assigned (see above). If
           specified, it causes a writer to put several updates into a single transaction. This transaction will
           last for the specified amount of time. By default, each update will be executed in a separate
           transaction. Each transaction generates a fair amount of overhead which can, thus, be reduced by
           activating this option. The draw-back is, that data covering the specified amount of time will be
           lost, for example, if a single statement within the transaction fails or if the database server
           crashes.

       Instance name
           Specify the plugin instance name that should be used instead of the database name (which is the
           default, if this option has not been specified). This allows one to query multiple databases of the
           same name on the same host (e.g.  when running multiple database server versions in parallel).  The
           plugin instance name can also be set from the query result using the PluginInstanceFrom option in
           Query block.

       Host hostname
           Specify the hostname or IP of the PostgreSQL server to connect to. If the value begins with a slash,
           it is interpreted as the directory name in which to look for the UNIX domain socket.

           This option is also used to determine the hostname that is associated with a collected data set. If
           it has been omitted or either begins with with a slash or equals localhost it will be replaced with
           the global hostname definition of collectd. Any other value will be passed literally to collectd when
           dispatching values. Also see the global Hostname and FQDNLookup options.

       Port port
           Specify the TCP port or the local UNIX domain socket file extension of the server.

       User username
           Specify the username to be used when connecting to the server.

       Password password
           Specify the password to be used when connecting to the server.

       ExpireDelay delay
           Skip expired values in query output.

       SSLMode disable|allow|prefer|require
           Specify whether to use an SSL connection when contacting the server. The following modes are
           supported:

           disable
               Do not use SSL at all.

           allow
               First, try to connect without using SSL. If that fails, try using SSL.

           prefer (default)
               First, try to connect using SSL. If that fails, try without using SSL.

           require
               Use SSL only.

       Instance name
           Specify the plugin instance name that should be used instead of the database name (which is the
           default, if this option has not been specified). This allows one to query multiple databases of the
           same name on the same host (e.g.  when running multiple database server versions in parallel).

       KRBSrvName kerberos_service_name
           Specify the Kerberos service name to use when authenticating with Kerberos 5 or GSSAPI. See the
           sections "Kerberos authentication" and "GSSAPI" of the PostgreSQL Documentation for details.

       Service service_name
           Specify the PostgreSQL service name to use for additional parameters. That service has to be defined
           in pg_service.conf and holds additional connection parameters. See the section "The Connection
           Service File" in the PostgreSQL Documentation for details.

       Query query
           Specifies a query which should be executed in the context of the database connection. This may be any
           of the predefined or user-defined queries. If no such option is given, it defaults to "backends",
           "transactions", "queries", "query_plans", "table_states", "disk_io" and "disk_usage" (unless a Writer
           has been specified). Else, the specified queries are used only.

       Writer writer
           Assigns the specified writer backend to the database connection. This causes all collected data to be
           send to the database using the settings defined in the writer configuration (see the section "FILTER
           CONFIGURATION" below for details on how to selectively send data to certain plugins).

           Each writer will register a flush callback which may be used when having long transactions enabled
           (see the CommitInterval option above). When issuing the FLUSH command (see collectd-unixsock(5) for
           details) the current transaction will be committed right away. Two different kinds of flush callbacks
           are available with the "postgresql" plugin:

           postgresql
               Flush all writer backends.

           postgresql-database
               Flush all writers of the specified database only.

   Plugin "powerdns"
       The "powerdns" plugin queries statistics from an authoritative PowerDNS nameserver and/or a PowerDNS
       recursor. Since both offer a wide variety of values, many of which are probably meaningless to most
       users, but may be useful for some. So you may chose which values to collect, but if you don't, some
       reasonable defaults will be collected.

         <Plugin "powerdns">
           <Server "server_name">
             Collect "latency"
             Collect "udp-answers" "udp-queries"
             Socket "/var/run/pdns.controlsocket"
           </Server>
           <Recursor "recursor_name">
             Collect "questions"
             Collect "cache-hits" "cache-misses"
             Socket "/var/run/pdns_recursor.controlsocket"
           </Recursor>
           LocalSocket "/opt/collectd/var/run/collectd-powerdns"
         </Plugin>

       Server and Recursor block
           The Server block defines one authoritative server to query, the Recursor does the same for an
           recursing server. The possible options in both blocks are the same, though. The argument defines a
           name for the server / recursor and is required.

           Collect Field
               Using the Collect statement you can select which values to collect. Here, you specify the name of
               the values as used by the PowerDNS servers, e. g.  "dlg-only-drops", "answers10-100".

               The method of getting the values differs for Server and Recursor blocks: When querying the server
               a "SHOW *" command is issued in any case, because that's the only way of getting multiple values
               out of the server at once.  collectd then picks out the values you have selected. When querying
               the recursor, a command is generated to query exactly these values. So if you specify invalid
               fields when querying the recursor, a syntax error may be returned by the daemon and collectd may
               not collect any values at all.

               If no Collect statement is given, the following Server values will be collected:

               latency
               packetcache-hit
               packetcache-miss
               packetcache-size
               query-cache-hit
               query-cache-miss
               recursing-answers
               recursing-questions
               tcp-answers
               tcp-queries
               udp-answers
               udp-queries

               The following Recursor values will be collected by default:

               noerror-answers
               nxdomain-answers
               servfail-answers
               sys-msec
               user-msec
               qa-latency
               cache-entries
               cache-hits
               cache-misses
               questions

               Please note that up to that point collectd doesn't know what values are available on the server
               and values that are added do not need a change of the mechanism so far. However, the values must
               be mapped to collectd's naming scheme, which is done using a lookup table that lists all known
               values. If values are added in the future and collectd does not know about them, you will get an
               error much like this:

                 powerdns plugin: submit: Not found in lookup table: foobar = 42

               In this case please file a bug report with the collectd team.

           Socket Path
               Configures the path to the UNIX domain socket to be used when connecting to the daemon. By
               default "${localstatedir}/run/pdns.controlsocket" will be used for an authoritative server and
               "${localstatedir}/run/pdns_recursor.controlsocket" will be used for the recursor.

       LocalSocket Path
           Querying the recursor is done using UDP. When using UDP over UNIX domain sockets, the client socket
           needs a name in the file system, too. You can set this local name to Path using the LocalSocket
           option. The default is "prefix/var/run/collectd-powerdns".

   Plugin "processes"
       Process Name
           Select more detailed statistics of processes matching this name. The statistics collected for these
           selected processes are size of the resident segment size (RSS), user- and system-time used, number of
           processes and number of threads, io data (where available) and minor and major pagefaults.

           Some platforms have a limit on the length of process names. Name must stay below this limit.

       ProcessMatch name regex
           Similar to the Process option this allows one to select more detailed statistics of processes
           matching the specified regex (see regex(7) for details). The statistics of all matching processes are
           summed up and dispatched to the daemon using the specified name as an identifier. This allows one to
           "group" several processes together. name must not contain slashes.

       CollectContextSwitch Boolean
           Collect context switch of the process.

   Plugin "protocols"
       Collects a lot of information about various network protocols, such as IP, TCP, UDP, etc.

       Available configuration options:

       Value Selector
           Selects whether or not to select a specific value. The string being matched is of the form
           "Protocol:ValueName", where Protocol will be used as the plugin instance and ValueName will be used
           as type instance. An example of the string being used would be "Tcp:RetransSegs".

           You can use regular expressions to match a large number of values with just one configuration option.
           To select all "extended" TCP values, you could use the following statement:

             Value "/^TcpExt:/"

           Whether only matched values are selected or all matched values are ignored depends on the
           IgnoreSelected. By default, only matched values are selected.  If no value is configured at all, all
           values will be selected.

           See /"IGNORELISTS" for details.

       IgnoreSelected true|false
           If set to true, inverts the selection made by Value, i. e. all matching values will be ignored.

   Plugin "python"
       This plugin embeds a Python-interpreter into collectd and provides an interface to collectd's plugin
       system. See collectd-python(5) for its documentation.

   Plugin "routeros"
       The "routeros" plugin connects to a device running RouterOS, the Linux-based operating system for routers
       by MikroTik. The plugin uses librouteros to connect and reads information about the interfaces and
       wireless connections of the device. The configuration supports querying multiple routers:

         <Plugin "routeros">
           <Router>
             Host "router0.example.com"
             User "collectd"
             Password "secr3t"
             CollectInterface true
             CollectCPULoad true
             CollectMemory true
           </Router>
           <Router>
             Host "router1.example.com"
             User "collectd"
             Password "5ecret"
             CollectInterface true
             CollectRegistrationTable true
             CollectDF true
             CollectDisk true
           </Router>
         </Plugin>

       As you can see above, the configuration of the routeros plugin consists of one or more <Router> blocks.
       Within each block, the following options are understood:

       Host Host
           Hostname or IP-address of the router to connect to.

       Port Port
           Port name or port number used when connecting. If left unspecified, the default will be chosen by
           librouteros, currently "8728". This option expects a string argument, even when a numeric port number
           is given.

       User User
           Use the user name User to authenticate. Defaults to "admin".

       Password Password
           Set the password used to authenticate.

       CollectInterface true|false
           When set to true, interface statistics will be collected for all interfaces present on the device.
           Defaults to false.

       CollectRegistrationTable true|false
           When set to true, information about wireless LAN connections will be collected. Defaults to false.

       CollectCPULoad true|false
           When set to true, information about the CPU usage will be collected. The number is a dimensionless
           value where zero indicates no CPU usage at all.  Defaults to false.

       CollectMemory true|false
           When enabled, the amount of used and free memory will be collected. How used memory is calculated is
           unknown, for example whether or not caches are counted as used space.  Defaults to false.

       CollectDF true|false
           When enabled, the amount of used and free disk space will be collected.  Defaults to false.

       CollectDisk true|false
           When enabled, the number of sectors written and bad blocks will be collected.  Defaults to false.

   Plugin "redis"
       The Redis plugin connects to one or more Redis servers and gathers information about each server's state.
       For each server there is a Node block which configures the connection parameters for this node.

         <Plugin redis>
           <Node "example">
               Host "localhost"
               Port "6379"
               Timeout 2000
               <Query "LLEN myqueue">
                 Type "queue_length"
                 Instance "myqueue"
               <Query>
           </Node>
         </Plugin>

       The information shown in the synopsis above is the default configuration which is used by the plugin if
       no configuration is present.

       Node Nodename
           The Node block identifies a new Redis node, that is a new Redis instance running in an specified host
           and port. The name for node is a canonical identifier which is used as plugin instance. It is limited
           to 64 characters in length.

       Host Hostname
           The Host option is the hostname or IP-address where the Redis instance is running on.

       Port Port
           The Port option is the TCP port on which the Redis instance accepts connections. Either a service
           name of a port number may be given. Please note that numerical port numbers must be given as a
           string, too.

       Password Password
           Use Password to authenticate when connecting to Redis.

       Timeout Milliseconds
           The Timeout option set the socket timeout for node response. Since the Redis read function is
           blocking, you should keep this value as low as possible. Keep in mind that the sum of all Timeout
           values for all Nodes should be lower than Interval defined globally.

       Query Querystring
           The Query block identifies a query to execute against the redis server.  There may be an arbitrary
           number of queries to execute.

       Type Collectd type
           Within a query definition, a valid collectd type to use as when submitting the result of the query.
           When not supplied, will default to gauge.

       Instance Type instance
           Within a query definition, an optional type instance to use when submitting the result of the query.
           When not supplied will default to the escaped command, up to 64 chars.

   Plugin "rrdcached"
       The "rrdcached" plugin uses the RRDtool accelerator daemon, rrdcached(1), to store values to RRD files in
       an efficient manner. The combination of the "rrdcached" plugin and the "rrdcached" daemon is very similar
       to the way the "rrdtool" plugin works (see below). The added abstraction layer provides a number of
       benefits, though: Because the cache is not within "collectd" anymore, it does not need to be flushed when
       "collectd" is to be restarted. This results in much shorter (if any) gaps in graphs, especially under
       heavy load. Also, the "rrdtool" command line utility is aware of the daemon so that it can flush values
       to disk automatically when needed. This allows one to integrate automated flushing of values into
       graphing solutions much more easily.

       There are disadvantages, though: The daemon may reside on a different host, so it may not be possible for
       "collectd" to create the appropriate RRD files anymore. And even if "rrdcached" runs on the same host, it
       may run in a different base directory, so relative paths may do weird stuff if you're not careful.

       So the recommended configuration is to let "collectd" and "rrdcached" run on the same host, communicating
       via a UNIX domain socket. The DataDir setting should be set to an absolute path, so that a changed base
       directory does not result in RRD files being created / expected in the wrong place.

       DaemonAddress Address
           Address of the daemon as understood by the "rrdc_connect" function of the RRD library. See
           rrdcached(1) for details. Example:

             <Plugin "rrdcached">
               DaemonAddress "unix:/var/run/rrdcached.sock"
             </Plugin>

       DataDir Directory
           Set the base directory in which the RRD files reside. If this is a relative path, it is relative to
           the working base directory of the "rrdcached" daemon!  Use of an absolute path is recommended.

       CreateFiles true|false
           Enables or disables the creation of RRD files. If the daemon is not running locally, or DataDir is
           set to a relative path, this will not work as expected. Default is true.

       CreateFilesAsync false|true
           When enabled, new RRD files are enabled asynchronously, using a separate thread that runs in the
           background. This prevents writes to block, which is a problem especially when many hundreds of files
           need to be created at once. However, since the purpose of creating the files asynchronously is not to
           block until the file is available, values before the file is available will be discarded.  When
           disabled (the default) files are created synchronously, blocking for a short while, while the file is
           being written.

       StepSize Seconds
           Force the stepsize of newly created RRD-files. Ideally (and per default) this setting is unset and
           the stepsize is set to the interval in which the data is collected. Do not use this option unless you
           absolutely have to for some reason. Setting this option may cause problems with the "snmp plugin",
           the "exec plugin" or when the daemon is set up to receive data from other hosts.

       HeartBeat Seconds
           Force the heartbeat of newly created RRD-files. This setting should be unset in which case the
           heartbeat is set to twice the StepSize which should equal the interval in which data is collected. Do
           not set this option unless you have a very good reason to do so.

       RRARows NumRows
           The "rrdtool plugin" calculates the number of PDPs per CDP based on the StepSize, this setting and a
           timespan. This plugin creates RRD-files with three times five RRAs, i. e. five RRAs with the CFs MIN,
           AVERAGE, and MAX. The five RRAs are optimized for graphs covering one hour, one day, one week, one
           month, and one year.

           So for each timespan, it calculates how many PDPs need to be consolidated into one CDP by
           calculating:
             number of PDPs = timespan / (stepsize * rrarows)

           Bottom line is, set this no smaller than the width of you graphs in pixels. The default is 1200.

       RRATimespan Seconds
           Adds an RRA-timespan, given in seconds. Use this option multiple times to have more then one RRA. If
           this option is never used, the built-in default of (3600, 86400, 604800, 2678400, 31622400) is used.

           For more information on how RRA-sizes are calculated see RRARows above.

       XFF Factor
           Set the "XFiles Factor". The default is 0.1. If unsure, don't set this option.  Factor must be in the
           range "[0.0-1.0)", i.e. between zero (inclusive) and one (exclusive).

       CollectStatistics false|true
           When set to true, various statistics about the rrdcached daemon will be collected, with "rrdcached"
           as the plugin name. Defaults to false.

           Statistics are read via rrdcacheds socket using the STATS command.  See rrdcached(1) for details.

   Plugin "rrdtool"
       You can use the settings StepSize, HeartBeat, RRARows, and XFF to fine-tune your RRD-files. Please read
       rrdcreate(1) if you encounter problems using these settings. If you don't want to dive into the depths of
       RRDtool, you can safely ignore these settings.

       DataDir Directory
           Set the directory to store RRD files under. By default RRD files are generated beneath the daemon's
           working directory, i.e. the BaseDir.

       CreateFilesAsync false|true
           When enabled, new RRD files are enabled asynchronously, using a separate thread that runs in the
           background. This prevents writes to block, which is a problem especially when many hundreds of files
           need to be created at once. However, since the purpose of creating the files asynchronously is not to
           block until the file is available, values before the file is available will be discarded.  When
           disabled (the default) files are created synchronously, blocking for a short while, while the file is
           being written.

       StepSize Seconds
           Force the stepsize of newly created RRD-files. Ideally (and per default) this setting is unset and
           the stepsize is set to the interval in which the data is collected. Do not use this option unless you
           absolutely have to for some reason. Setting this option may cause problems with the "snmp plugin",
           the "exec plugin" or when the daemon is set up to receive data from other hosts.

       HeartBeat Seconds
           Force the heartbeat of newly created RRD-files. This setting should be unset in which case the
           heartbeat is set to twice the StepSize which should equal the interval in which data is collected. Do
           not set this option unless you have a very good reason to do so.

       RRARows NumRows
           The "rrdtool plugin" calculates the number of PDPs per CDP based on the StepSize, this setting and a
           timespan. This plugin creates RRD-files with three times five RRAs, i.e. five RRAs with the CFs MIN,
           AVERAGE, and MAX. The five RRAs are optimized for graphs covering one hour, one day, one week, one
           month, and one year.

           So for each timespan, it calculates how many PDPs need to be consolidated into one CDP by
           calculating:
             number of PDPs = timespan / (stepsize * rrarows)

           Bottom line is, set this no smaller than the width of you graphs in pixels. The default is 1200.

       RRATimespan Seconds
           Adds an RRA-timespan, given in seconds. Use this option multiple times to have more then one RRA. If
           this option is never used, the built-in default of (3600, 86400, 604800, 2678400, 31622400) is used.

           For more information on how RRA-sizes are calculated see RRARows above.

       XFF Factor
           Set the "XFiles Factor". The default is 0.1. If unsure, don't set this option.  Factor must be in the
           range "[0.0-1.0)", i.e. between zero (inclusive) and one (exclusive).

       CacheFlush Seconds
           When the "rrdtool" plugin uses a cache (by setting CacheTimeout, see below) it writes all values for
           a certain RRD-file if the oldest value is older than (or equal to) the number of seconds specified.
           If some RRD-file is not updated anymore for some reason (the computer was shut down, the network is
           broken, etc.) some values may still be in the cache. If CacheFlush is set, then the entire cache is
           searched for entries older than CacheTimeout seconds and written to disk every Seconds seconds. Since
           this is kind of expensive and does nothing under normal circumstances, this value should not be too
           small.  900 seconds might be a good value, though setting this to 7200 seconds doesn't normally do
           much harm either.

       CacheTimeout Seconds
           If this option is set to a value greater than zero, the "rrdtool plugin" will save values in a cache,
           as described above. Writing multiple values at once reduces IO-operations and thus lessens the load
           produced by updating the files.  The trade off is that the graphs kind of "drag behind" and that more
           memory is used.

       WritesPerSecond Updates
           When collecting many statistics with collectd and the "rrdtool" plugin, you will run serious
           performance problems. The CacheFlush setting and the internal update queue assert that collectd
           continues to work just fine even under heavy load, but the system may become very unresponsive and
           slow. This is a problem especially if you create graphs from the RRD files on the same machine, for
           example using the "graph.cgi" script included in the "contrib/collection3/" directory.

           This setting is designed for very large setups. Setting this option to a value between 25 and 80
           updates per second, depending on your hardware, will leave the server responsive enough to draw
           graphs even while all the cached values are written to disk. Flushed values, i. e. values that are
           forced to disk by the FLUSH command, are not effected by this limit. They are still written as fast
           as possible, so that web frontends have up to date data when generating graphs.

           For example: If you have 100,000 RRD files and set WritesPerSecond to 30 updates per second, writing
           all values to disk will take approximately 56 minutes. Together with the flushing ability that's
           integrated into "collection3" you'll end up with a responsive and fast system, up to date graphs and
           basically a "backup" of your values every hour.

       RandomTimeout Seconds
           When set, the actual timeout for each value is chosen randomly between CacheTimeout-RandomTimeout and
           CacheTimeout+RandomTimeout. The intention is to avoid high load situations that appear when many
           values timeout at the same time. This is especially a problem shortly after the daemon starts,
           because all values were added to the internal cache at roughly the same time.

   Plugin "sensors"
       The Sensors plugin uses lm_sensors to retrieve sensor-values. This means that all the needed modules have
       to be loaded and lm_sensors has to be configured (most likely by editing /etc/sensors.conf. Read
       sensors.conf(5) for details.

       The lm_sensors homepage can be found at <http://secure.netroedge.com/~lm78/>.

       SensorConfigFile File
           Read the lm_sensors configuration from File. When unset (recommended), the library's default will be
           used.

       Sensor chip-bus-address/type-feature
           Selects the name of the sensor which you want to collect or ignore, depending on the IgnoreSelected
           below. For example, the option "Sensor it8712-isa-0290/voltage-in1" will cause collectd to gather
           data for the voltage sensor in1 of the it8712 on the isa bus at the address 0290.

           See /"IGNORELISTS" for details.

       IgnoreSelected true|false
           If no configuration if given, the sensors-plugin will collect data from all sensors. This may not be
           practical, especially for uninteresting sensors.  Thus, you can use the Sensor-option to pick the
           sensors you're interested in. Sometimes, however, it's easier/preferred to collect all sensors except
           a few ones. This option enables you to do that: By setting IgnoreSelected to true the effect of
           Sensor is inverted: All selected sensors are ignored and all other sensors are collected.

       UseLabels true|false
           Configures how sensor readings are reported. When set to true, sensor readings are reported using
           their descriptive label (e.g. "VCore"). When set to false (the default) the sensor name is used
           ("in0").

   Plugin "sigrok"
       The sigrok plugin uses libsigrok to retrieve measurements from any device supported by the sigrok
       <http://sigrok.org/> project.

       Synopsis

        <Plugin sigrok>
          LogLevel 3
          <Device "AC Voltage">
             Driver "fluke-dmm"
             MinimumInterval 10
             Conn "/dev/ttyUSB2"
          </Device>
          <Device "Sound Level">
             Driver "cem-dt-885x"
             Conn "/dev/ttyUSB1"
          </Device>
        </Plugin>

       LogLevel 0-5
           The sigrok logging level to pass on to the collectd log, as a number between 0 and 5 (inclusive).
           These levels correspond to "None", "Errors", "Warnings", "Informational", "Debug "and "Spew",
           respectively.  The default is 2 ("Warnings"). The sigrok log messages, regardless of their level, are
           always submitted to collectd at its INFO log level.

       <Device Name>
           A sigrok-supported device, uniquely identified by this section's options. The Name is passed to
           collectd as the plugin instance.

       Driver DriverName
           The sigrok driver to use for this device.

       Conn ConnectionSpec
           If the device cannot be auto-discovered, or more than one might be discovered by the driver,
           ConnectionSpec specifies the connection string to the device.  It can be of the form of a device path
           (e.g. "/dev/ttyUSB2"), or, in case of a non-serial USB-connected device, the USB VendorID.ProductID
           separated by a period (e.g. 0403.6001). A USB device can also be specified as Bus.Address
           (e.g. 1.41).

       SerialComm SerialSpec
           For serial devices with non-standard port settings, this option can be used to specify them in a form
           understood by sigrok, e.g. "9600/8n1".  This should not be necessary; drivers know how to communicate
           with devices they support.

       MinimumInterval Seconds
           Specifies the minimum time between measurement dispatches to collectd, in seconds. Since some sigrok
           supported devices can acquire measurements many times per second, it may be necessary to throttle
           these. For example, the RRD plugin cannot process writes more than once per second.

           The default MinimumInterval is 0, meaning measurements received from the device are always dispatched
           to collectd. When throttled, unused measurements are discarded.

   Plugin "smart"
       The "smart" plugin collects SMART information from physical disks. Values collectd include temperature,
       power cycle count, poweron time and bad sectors. Also, all SMART attributes are collected along with the
       normalized current value, the worst value, the threshold and a human readable value.

       Using the following two options you can ignore some disks or configure the collection only of specific
       disks.

       Disk Name
           Select the disk Name. Whether it is collected or ignored depends on the IgnoreSelected setting, see
           below. As with other plugins that use the daemon's ignorelist functionality, a string that starts and
           ends with a slash is interpreted as a regular expression. Examples:

             Disk "sdd"
             Disk "/hda[34]/"

           See /"IGNORELISTS" for details.

       IgnoreSelected true|false
           Sets whether selected disks, i. e. the ones matches by any of the Disk statements, are ignored or if
           all other disks are ignored. The behavior (hopefully) is intuitive: If no Disk option is configured,
           all disks are collected. If at least one Disk option is given and no IgnoreSelected or set to false,
           only matching disks will be collected. If IgnoreSelected is set to true, all disks are collected
           except the ones matched.

       IgnoreSleepMode true|false
           Normally, the "smart" plugin will ignore disks that are reported to be asleep.  This option disables
           the sleep mode check and allows the plugin to collect data from these disks anyway. This is useful in
           cases where libatasmart mistakenly reports disks as asleep because it has not been updated to
           incorporate support for newer idle states in the ATA spec.

       UseSerial true|false
           A disk's kernel name (e.g., sda) can change from one boot to the next. If this option is enabled, the
           "smart" plugin will use the disk's serial number (e.g., HGST_HUH728080ALE600_2EJ8VH8X) instead of the
           kernel name as the key for storing data. This ensures that the data for a given disk will be kept
           together even if the kernel name changes.

   Plugin "snmp"
       Since the configuration of the "snmp plugin" is a little more complicated than other plugins, its
       documentation has been moved to an own manpage, collectd-snmp(5). Please see there for details.

   Plugin "statsd"
       The statsd plugin listens to a UDP socket, reads "events" in the statsd protocol and dispatches rates or
       other aggregates of these numbers periodically.

       The plugin implements the Counter, Timer, Gauge and Set types which are dispatched as the collectd types
       "derive", "latency", "gauge" and "objects" respectively.

       The following configuration options are valid:

       Host Host
           Bind to the hostname / address Host. By default, the plugin will bind to the "any" address, i.e.
           accept packets sent to any of the hosts addresses.

       Port Port
           UDP port to listen to. This can be either a service name or a port number.  Defaults to 8125.

       DeleteCounters false|true
       DeleteTimers false|true
       DeleteGauges false|true
       DeleteSets false|true
           These options control what happens if metrics are not updated in an interval.  If set to False, the
           default, metrics are dispatched unchanged, i.e. the rate of counters and size of sets will be zero,
           timers report "NaN" and gauges are unchanged. If set to True, the such metrics are not dispatched and
           removed from the internal cache.

       CounterSum false|true
           When enabled, creates a "count" metric which reports the change since the last read. This option
           primarily exists for compatibility with the statsd implementation by Etsy.

       TimerPercentile Percent
           Calculate and dispatch the configured percentile, i.e. compute the latency, so that Percent of all
           reported timers are smaller than or equal to the computed latency. This is useful for cutting off the
           long tail latency, as it's often done in Service Level Agreements (SLAs).

           Different percentiles can be calculated by setting this option several times.  If none are specified,
           no percentiles are calculated / dispatched.

       TimerLower false|true
       TimerUpper false|true
       TimerSum false|true
       TimerCount false|true
           Calculate and dispatch various values out of Timer metrics received during an interval. If set to
           False, the default, these values aren't calculated / dispatched.

   Plugin "swap"
       The Swap plugin collects information about used and available swap space. On Linux and Solaris, the
       following options are available:

       ReportByDevice false|true
           Configures how to report physical swap devices. If set to false (the default), the summary over all
           swap devices is reported only, i.e. the globally used and available space over all devices. If true
           is configured, the used and available space of each device will be reported separately.

           This option is only available if the Swap plugin can read "/proc/swaps" (under Linux) or use the
           swapctl(2) mechanism (under Solaris).

       ReportBytes false|true
           When enabled, the swap I/O is reported in bytes. When disabled, the default, swap I/O is reported in
           pages. This option is available under Linux only.

       ValuesAbsolute true|false
           Enables or disables reporting of absolute swap metrics, i.e. number of bytes available and used.
           Defaults to true.

       ValuesPercentage false|true
           Enables or disables reporting of relative swap metrics, i.e. percent available and free. Defaults to
           false.

           This is useful for deploying collectd in a heterogeneous environment, where swap sizes differ and you
           want to specify generic thresholds or similar.

   Plugin "syslog"
       LogLevel debug|info|notice|warning|err
           Sets the log-level. If, for example, set to notice, then all events with severity notice, warning, or
           err will be submitted to the syslog-daemon.

           Please note that debug is only available if collectd has been compiled with debugging support.

       NotifyLevel OKAY|WARNING|FAILURE
           Controls which notifications should be sent to syslog. The default behaviour is not to send any. Less
           severe notifications always imply logging more severe notifications: Setting this to OKAY means all
           notifications will be sent to syslog, setting this to WARNING will send WARNING and FAILURE
           notifications but will dismiss OKAY notifications. Setting this option to FAILURE will only send
           failures to syslog.

   Plugin "table"
       The "table plugin" provides generic means to parse tabular data and dispatch user specified values.
       Values are selected based on column numbers. For example, this plugin may be used to get values from the
       Linux proc(5) filesystem or CSV (comma separated values) files.

         <Plugin table>
           <Table "/proc/slabinfo">
             Instance "slabinfo"
             Separator " "
             <Result>
               Type gauge
               InstancePrefix "active_objs"
               InstancesFrom 0
               ValuesFrom 1
             </Result>
             <Result>
               Type gauge
               InstancePrefix "objperslab"
               InstancesFrom 0
               ValuesFrom 4
             </Result>
           </Table>
         </Plugin>

       The configuration consists of one or more Table blocks, each of which configures one file to parse.
       Within each Table block, there are one or more Result blocks, which configure which data to select and
       how to interpret it.

       The following options are available inside a Table block:

       Instance instance
           If specified, instance is used as the plugin instance. So, in the above example, the plugin name
           "table-slabinfo" would be used. If omitted, the filename of the table is used instead, with all
           special characters replaced with an underscore ("_").

       Separator string
           Any character of string is interpreted as a delimiter between the different columns of the table. A
           sequence of two or more contiguous delimiters in the table is considered to be a single delimiter,
           i. e. there cannot be any empty columns. The plugin uses the strtok_r(3) function to parse the lines
           of a table - see its documentation for more details. This option is mandatory.

           A horizontal tab, newline and carriage return may be specified by "\\t", "\\n" and "\\r"
           respectively. Please note that the double backslashes are required because of collectd's config
           parsing.

       The following options are available inside a Result block:

       Type type
           Sets the type used to dispatch the values to the daemon. Detailed information about types and their
           configuration can be found in types.db(5). This option is mandatory.

       InstancePrefix prefix
           If specified, prepend prefix to the type instance. If omitted, only the InstancesFrom option is
           considered for the type instance.

       InstancesFrom column0 [column1 ...]
           If specified, the content of the given columns (identified by the column number starting at zero)
           will be used to create the type instance for each row. Multiple values (and the instance prefix) will
           be joined together with dashes (-) as separation character. If omitted, only the InstancePrefix
           option is considered for the type instance.

           The plugin itself does not check whether or not all built instances are different. ItXs your
           responsibility to assure that each is unique. This is especially true, if you do not specify
           InstancesFrom: You have to make sure that the table only contains one row.

           If neither InstancePrefix nor InstancesFrom is given, the type instance will be empty.

       ValuesFrom column0 [column1 ...]
           Specifies the columns (identified by the column numbers starting at zero) whose content is used as
           the actual data for the data sets that are dispatched to the daemon. How many such columns you need
           is determined by the Type setting above. If you specify too many or not enough columns, the plugin
           will complain about that and no data will be submitted to the daemon. The plugin uses strtoll(3) and
           strtod(3) to parse counter and gauge values respectively, so anything supported by those functions is
           supported by the plugin as well. This option is mandatory.

   Plugin "tail"
       The "tail plugin" follows logfiles, just like tail(1) does, parses each line and dispatches found values.
       What is matched can be configured by the user using (extended) regular expressions, as described in
       regex(7).

         <Plugin "tail">
           <File "/var/log/exim4/mainlog">
             Instance "exim"
             Interval 60
             <Match>
               Regex "S=([1-9][0-9]*)"
               DSType "CounterAdd"
               Type "ipt_bytes"
               Instance "total"
             </Match>
             <Match>
               Regex "\\<R=local_user\\>"
               ExcludeRegex "\\<R=local_user\\>.*mail_spool defer"
               DSType "CounterInc"
               Type "counter"
               Instance "local_user"
             </Match>
             <Match>
               Regex "l=([0-9]*\\.[0-9]*)"
               <DSType "Distribution">
                 Percentile 99
                 Bucket 0 100
               </DSType>
               Type "latency"
               Instance "foo"
             </Match>
           </File>
         </Plugin>

       The config consists of one or more File blocks, each of which configures one logfile to parse. Within
       each File block, there are one or more Match blocks, which configure a regular expression to search for.

       The Instance option in the File block may be used to set the plugin instance. So in the above example the
       plugin name "tail-foo" would be used.  This plugin instance is for all Match blocks that follow it, until
       the next Instance option. This way you can extract several plugin instances from one logfile, handy when
       parsing syslog and the like.

       The Interval option allows you to define the length of time between reads. If this is not set, the
       default Interval will be used.

       Each Match block has the following options to describe how the match should be performed:

       Regex regex
           Sets the regular expression to use for matching against a line. The first subexpression has to match
           something that can be turned into a number by strtoll(3) or strtod(3), depending on the value of
           "CounterAdd", see below. Because extended regular expressions are used, you do not need to use
           backslashes for subexpressions! If in doubt, please consult regex(7). Due to collectd's config
           parsing you need to escape backslashes, though. So if you want to match literal parentheses you need
           to do the following:

             Regex "SPAM \\(Score: (-?[0-9]+\\.[0-9]+)\\)"

       ExcludeRegex regex
           Sets an optional regular expression to use for excluding lines from the match.  An example which
           excludes all connections from localhost from the match:

             ExcludeRegex "127\\.0\\.0\\.1"

       DSType Type
           Sets how the values are cumulated. Type is one of:

           GaugeAverage
               Calculate the average.

           GaugeMin
               Use the smallest number only.

           GaugeMax
               Use the greatest number only.

           GaugeLast
               Use the last number found.

           GaugePersist
               Use the last number found. The number is not reset at the end of an interval.  It is continously
               reported until another number is matched. This is intended for cases in which only state changes
               are reported, for example a thermometer that only reports the temperature when it changes.

           CounterSet
           DeriveSet
           AbsoluteSet
               The matched number is a counter. Simply sets the internal counter to this value. Variants exist
               for "COUNTER", "DERIVE", and "ABSOLUTE" data sources.

           GaugeAdd
           CounterAdd
           DeriveAdd
               Add the matched value to the internal counter. In case of DeriveAdd, the matched number may be
               negative, which will effectively subtract from the internal counter.

           GaugeInc
           CounterInc
           DeriveInc
               Increase the internal counter by one. These DSType are the only ones that do not use the matched
               subexpression, but simply count the number of matched lines. Thus, you may use a regular
               expression without submatch in this case.

           Distribution
               Type to do calculations based on the distribution of values, primarily calculating percentiles.
               This is primarily geared towards latency, but can be used for other metrics as well. The range of
               values tracked with this setting must be in the range (0X2^34) and can be fractional. Please note
               that neither zero nor 2^34 are inclusive bounds, i.e. zero cannot be handled by a distribution.

               This option must be used together with the Percentile and/or Bucket options.

               Synopsis:

                 <DSType "Distribution">
                   Percentile 99
                   Bucket 0 100
                 </DSType>

               Percentile Percent
                   Calculate and dispatch the configured percentile, i.e. compute the value, so that Percent of
                   all matched values are smaller than or equal to the computed latency.

                   Metrics are reported with the type Type (the value of the above option) and the type instance
                   "[<Instance>-]<Percent>".

                   This option may be repeated to calculate more than one percentile.

               Bucket lower_bound upper_bound
                   Export the number of values (a "DERIVE") falling within the given range. Both, lower_bound
                   and upper_bound may be a fractional number, such as 0.5.  Each Bucket option specifies an
                   interval "(lower_bound, upper_bound]", i.e. the range excludes the lower bound and includes
                   the upper bound. lower_bound and upper_bound may be zero, meaning no lower/upper bound.

                   To export the entire (0Xinf) range without overlap, use the upper bound of the previous range
                   as the lower bound of the following range. In other words, use the following schema:

                     Bucket   0   1
                     Bucket   1   2
                     Bucket   2   5
                     Bucket   5  10
                     Bucket  10  20
                     Bucket  20  50
                     Bucket  50   0

                   Metrics are reported with the type "bucket" and the type instance
                   "<Type>[-<Instance>]-<lower_bound>_<upper_bound>".

                   This option may be repeated to calculate more than one rate.

           The Gauge* and Distribution types interpret the submatch as a floating point number, using strtod(3).
           The Counter* and AbsoluteSet types interpret the submatch as an unsigned integer using strtoull(3).
           The Derive* types interpret the submatch as a signed integer using strtoll(3). CounterInc and
           DeriveInc do not use the submatch at all and it may be omitted in this case.

       Type Type
           Sets the type used to dispatch this value. Detailed information about types and their configuration
           can be found in types.db(5).

       Instance TypeInstance
           This optional setting sets the type instance to use.

   Plugin "tail_csv"
       The tail_csv plugin reads files in the CSV format, e.g. the statistics file written by Snort.

       Synopsis:

        <Plugin "tail_csv">
          <Metric "snort-dropped">
              Type "percent"
              Instance "dropped"
              Index 1
          </Metric>
          <File "/var/log/snort/snort.stats">
              Instance "snort-eth0"
              Interval 600
              Collect "snort-dropped"
          </File>
        </Plugin>

       The configuration consists of one or more Metric blocks that define an index into the line of the CSV
       file and how this value is mapped to collectd's internal representation. These are followed by one or
       more Instance blocks which configure which file to read, in which interval and which metrics to extract.

       <Metric Name>
           The Metric block configures a new metric to be extracted from the statistics file and how it is
           mapped on collectd's data model. The string Name is only used inside the Instance blocks to refer to
           this block, so you can use one Metric block for multiple CSV files.

           Type Type
               Configures which Type to use when dispatching this metric. Types are defined in the types.db(5)
               file, see the appropriate manual page for more information on specifying types. Only types with a
               single data source are supported by the tail_csv plugin. The information whether the value is an
               absolute value (i.e. a "GAUGE") or a rate (i.e. a "DERIVE") is taken from the Type's definition.

           Instance TypeInstance
               If set, TypeInstance is used to populate the type instance field of the created value lists.
               Otherwise, no type instance is used.

           ValueFrom Index
               Configure to read the value from the field with the zero-based index Index.  If the value is
               parsed as signed integer, unsigned integer or double depends on the Type setting, see above.

       <File Path>
           Each File block represents one CSV file to read. There must be at least one File block but there can
           be multiple if you have multiple CSV files.

           Instance PluginInstance
               Sets the plugin instance used when dispatching the values.

           Collect Metric
               Specifies which Metric to collect. This option must be specified at least once, and you can use
               this option multiple times to specify more than one metric to be extracted from this statistic
               file.

           Interval Seconds
               Configures the interval in which to read values from this instance / file.  Defaults to the
               plugin's default interval.

           TimeFrom Index
               Rather than using the local time when dispatching a value, read the timestamp from the field with
               the zero-based index Index. The value is interpreted as seconds since epoch. The value is parsed
               as a double and may be factional.

   Plugin "teamspeak2"
       The "teamspeak2 plugin" connects to the query port of a teamspeak2 server and polls interesting global
       and virtual server data. The plugin can query only one physical server but unlimited virtual servers. You
       can use the following options to configure it:

       Host hostname/ip
           The hostname or ip which identifies the physical server.  Default: 127.0.0.1

       Port port
           The query port of the physical server. This needs to be a string.  Default: "51234"

       Server port
           This option has to be added once for every virtual server the plugin should query. If you want to
           query the virtual server on port 8767 this is what the option would look like:

             Server "8767"

           This option, although numeric, needs to be a string, i. e. you must use quotes around it! If no such
           statement is given only global information will be collected.

   Plugin "ted"
       The TED plugin connects to a device of "The Energy Detective", a device to measure power consumption.
       These devices are usually connected to a serial (RS232) or USB port. The plugin opens a configured device
       and tries to read the current energy readings. For more information on TED, visit
       <http://www.theenergydetective.com/>.

       Available configuration options:

       Device Path
           Path to the device on which TED is connected. collectd will need read and write permissions on that
           file.

           Default: /dev/ttyUSB0

       Retries Num
           Apparently reading from TED is not that reliable. You can therefore configure a number of retries
           here. You only configure the retries here, to if you specify zero, one reading will be performed (but
           no retries if that fails); if you specify three, a maximum of four readings are performed. Negative
           values are illegal.

           Default: 0

   Plugin "tcpconns"
       The "tcpconns plugin" counts the number of currently established TCP connections based on the local port
       and/or the remote port. Since there may be a lot of connections the default if to count all connections
       with a local port, for which a listening socket is opened. You can use the following options to fine-tune
       the ports you are interested in:

       ListeningPorts true|false
           If this option is set to true, statistics for all local ports for which a listening socket exists are
           collected. The default depends on LocalPort and RemotePort (see below): If no port at all is
           specifically selected, the default is to collect listening ports. If specific ports (no matter if
           local or remote ports) are selected, this option defaults to false, i. e. only the selected ports
           will be collected unless this option is set to true specifically.

       LocalPort Port
           Count the connections to a specific local port. This can be used to see how many connections are
           handled by a specific daemon, e. g. the mailserver.  You have to specify the port in numeric form, so
           for the mailserver example you'd need to set 25.

       RemotePort Port
           Count the connections to a specific remote port. This is useful to see how much a remote service is
           used. This is most useful if you want to know how many connections a local service has opened to
           remote services, e. g. how many connections a mail server or news server has to other mail or news
           servers, or how many connections a web proxy holds to web servers. You have to give the port in
           numeric form.

       AllPortsSummary true|false
           If this option is set to true a summary of statistics from all connections are collected. This option
           defaults to false.

   Plugin "thermal"
       ForceUseProcfs true|false
           By default, the Thermal plugin tries to read the statistics from the Linux "sysfs" interface. If that
           is not available, the plugin falls back to the "procfs" interface. By setting this option to true,
           you can force the plugin to use the latter. This option defaults to false.

       Device Device
           Selects the name of the thermal device that you want to collect or ignore, depending on the value of
           the IgnoreSelected option. This option may be used multiple times to specify a list of devices.

           See /"IGNORELISTS" for details.

       IgnoreSelected true|false
           Invert the selection: If set to true, all devices except the ones that match the device names
           specified by the Device option are collected. By default only selected devices are collected if a
           selection is made. If no selection is configured at all, all devices are selected.

   Plugin "threshold"
       The Threshold plugin checks values collected or received by collectd against a configurable threshold and
       issues notifications if values are out of bounds.

       Documentation for this plugin is available in the collectd-threshold(5) manual page.

   Plugin "tokyotyrant"
       The TokyoTyrant plugin connects to a TokyoTyrant server and collects a couple metrics: number of records,
       and database size on disk.

       Host Hostname/IP
           The hostname or IP which identifies the server.  Default: 127.0.0.1

       Port Service/Port
           The query port of the server. This needs to be a string, even if the port is given in its numeric
           form.  Default: 1978

   Plugin "turbostat"
       The Turbostat plugin reads CPU frequency and C-state residency on modern Intel processors by using Model
       Specific Registers.

       CoreCstates Bitmask(Integer)
           Bit mask of the list of core C-states supported by the processor.  This option should only be used if
           the automated detection fails.  Default value extracted from the CPU model and family.

           Currently supported C-states (by this plugin): 3, 6, 7

           Example:

             All states (3, 6 and 7):
             (1<<3) + (1<<6) + (1<<7) = 392

       PackageCstates Bitmask(Integer)
           Bit mask of the list of packages C-states supported by the processor. This option should only be used
           if the automated detection fails. Default value extracted from the CPU model and family.

           Currently supported C-states (by this plugin): 2, 3, 6, 7, 8, 9, 10

           Example:

             States 2, 3, 6 and 7:
             (1<<2) + (1<<3) + (1<<6) + (1<<7) = 396

       SystemManagementInterrupt true|false
           Boolean enabling the collection of the I/O System-Management Interrupt counter.  This option should
           only be used if the automated detection fails or if you want to disable this feature.

       DigitalTemperatureSensor true|false
           Boolean enabling the collection of the temperature of each core. This option should only be used if
           the automated detection fails or if you want to disable this feature.

       TCCActivationTemp Temperature
           Thermal Control Circuit Activation Temperature of the installed CPU. This temperature is used when
           collecting the temperature of cores or packages. This option should only be used if the automated
           detection fails. Default value extracted from MSR_IA32_TEMPERATURE_TARGET.

       RunningAveragePowerLimit Bitmask(Integer)
           Bit mask of the list of elements to be thermally monitored. This option should only be used if the
           automated detection fails or if you want to disable some collections. The different bits of this bit
           mask accepted by this plugin are:

           0 ('1'): Package
           1 ('2'): DRAM
           2 ('4'): Cores
           3 ('8'): Embedded graphic device
       LogicalCoreNames true|false
           Boolean enabling the use of logical core numbering for per core statistics.  When enabled, "cpu<n>"
           is used as plugin instance, where n is a sequential number assigned by the kernel. Otherwise,
           "core<n>" is used where n is the n-th core of the socket, causing name conflicts when there is more
           than one socket.

   Plugin "unixsock"
       SocketFile Path
           Sets the socket-file which is to be created.

       SocketGroup Group
           If running as root change the group of the UNIX-socket after it has been created. Defaults to
           collectd.

       SocketPerms Permissions
           Change the file permissions of the UNIX-socket after it has been created. The permissions must be
           given as a numeric, octal value as you would pass to chmod(1). Defaults to 0770.

       DeleteSocket false|true
           If set to true, delete the socket file before calling bind(2), if a file with the given name already
           exists. If collectd crashes a socket file may be left over, preventing the daemon from opening a new
           socket when restarted.  Since this is potentially dangerous, this defaults to false.

   Plugin "uuid"
       This plugin, if loaded, causes the Hostname to be taken from the machine's UUID. The UUID is a
       universally unique designation for the machine, usually taken from the machine's BIOS. This is most
       useful if the machine is running in a virtual environment such as Xen, in which case the UUID is
       preserved across shutdowns and migration.

       The following methods are used to find the machine's UUID, in order:

       •   Check /etc/uuid (or UUIDFile).

       •   Check for UUID from HAL (<http://www.freedesktop.org/wiki/Software/hal>) if present.

       •   Check for UUID from "dmidecode" / SMBIOS.

       •   Check for UUID from Xen hypervisor.

       If no UUID can be found then the hostname is not modified.

       UUIDFile Path
           Take the UUID from the given file (default /etc/uuid).

   Plugin "varnish"
       The varnish plugin collects information about Varnish, an HTTP accelerator.  It collects a subset of the
       values displayed by varnishstat(1), and organizes them in categories which can be enabled or disabled.
       Currently only metrics shown in varnishstat(1)'s MAIN section are collected. The exact meaning of each
       metric can be found in varnish-counters(7).

       Synopsis:

        <Plugin "varnish">
          <Instance "example">
            CollectBackend     true
            CollectBan         false
            CollectCache       true
            CollectConnections true
            CollectDirectorDNS false
            CollectESI         false
            CollectFetch       false
            CollectHCB         false
            CollectObjects     false
            CollectPurge       false
            CollectSession     false
            CollectSHM         true
            CollectSMA         false
            CollectSMS         false
            CollectSM          false
            CollectStruct      false
            CollectTotals      false
            CollectUptime      false
            CollectVCL         false
            CollectVSM         false
            CollectWorkers     false
          </Instance>
        </Plugin>

       The configuration consists of one or more <Instance Name> blocks. Name is the parameter passed to
       "varnishd -n". If left empty, it will collectd statistics from the default "varnishd" instance (this
       should work fine in most cases).

       Inside each <Instance> blocks, the following options are recognized:

       CollectBackend true|false
           Back-end connection statistics, such as successful, reused, and closed connections. True by default.

       CollectBan true|false
           Statistics about ban operations, such as number of bans added, retired, and number of objects tested
           against ban operations. Only available with Varnish 3.x and above. False by default.

       CollectCache true|false
           Cache hits and misses. True by default.

       CollectConnections true|false
           Number of client connections received, accepted and dropped. True by default.

       CollectDirectorDNS true|false
           DNS director lookup cache statistics. Only available with Varnish 3.x. False by default.

       CollectESI true|false
           Edge Side Includes (ESI) parse statistics. False by default.

       CollectFetch true|false
           Statistics about fetches (HTTP requests sent to the backend). False by default.

       CollectHCB true|false
           Inserts and look-ups in the crit bit tree based hash. Look-ups are divided into locked and unlocked
           look-ups. False by default.

       CollectObjects true|false
           Statistics on cached objects: number of objects expired, nuked (prematurely expired), saved, moved,
           etc. False by default.

       CollectPurge true|false
           Statistics about purge operations, such as number of purges added, retired, and number of objects
           tested against purge operations. Only available with Varnish 2.x. False by default.

       CollectSession true|false
           Client session statistics. Number of past and current sessions, session herd and linger counters,
           etc. False by default. Note that if using Varnish 4.x, some metrics found in the Connections and
           Threads sections with previous versions of Varnish have been moved here.

       CollectSHM true|false
           Statistics about the shared memory log, a memory region to store log messages which is flushed to
           disk when full. True by default.

       CollectSMA true|false
           malloc or umem (umem_alloc(3MALLOC) based) storage statistics. The umem storage component is Solaris
           specific. Only available with Varnish 2.x. False by default.

       CollectSMS true|false
           synth (synthetic content) storage statistics. This storage component is used internally only. False
           by default.

       CollectSM true|false
           file (memory mapped file) storage statistics. Only available with Varnish 2.x.  False by default.

       CollectStruct true|false
           Current varnish internal state statistics. Number of current sessions, objects in cache store, open
           connections to backends (with Varnish 2.x), etc. False by default.

       CollectTotals true|false
           Collects overview counters, such as the number of sessions created, the number of requests and bytes
           transferred. False by default.

       CollectUptime true|false
           Varnish uptime. Only available with Varnish 3.x and above. False by default.

       CollectVCL true|false
           Number of total (available + discarded) VCL (config files). False by default.

       CollectVSM true|false
           Collect statistics about Varnish's shared memory usage (used by the logging and statistics
           subsystems). Only available with Varnish 4.x. False by default.

       CollectWorkers true|false
           Collect statistics about worker threads. False by default.

   Plugin "virt"
       This plugin allows CPU, disk and network load to be collected for virtualized guests on the machine. This
       means that these metrics can be collected for guest systems without installing any software on them -
       collectd only runs on the host system. The statistics are collected through libvirt
       (<http://libvirt.org/>).

       Only Connection is required.

       Connection uri
           Connect to the hypervisor given by uri. For example if using Xen use:

            Connection "xen:///"

           Details which URIs allowed are given at <http://libvirt.org/uri.html>.

       RefreshInterval seconds
           Refresh the list of domains and devices every seconds. The default is 60 seconds. Setting this to be
           the same or smaller than the Interval will cause the list of domains and devices to be refreshed on
           every iteration.

           Refreshing the devices in particular is quite a costly operation, so if your virtualization setup is
           static you might consider increasing this. If this option is set to 0, refreshing is disabled
           completely.

       Domain name
       BlockDevice name:dev
       InterfaceDevice name:dev
       IgnoreSelected true|false
           Select which domains and devices are collected.

           If IgnoreSelected is not given or false then only the listed domains and disk/network devices are
           collected.

           If IgnoreSelected is true then the test is reversed and the listed domains and disk/network devices
           are ignored, while the rest are collected.

           The domain name and device names may use a regular expression, if the name is surrounded by /.../ and
           collectd was compiled with support for regexps.

           The default is to collect statistics for all domains and all their devices.

           Example:

            BlockDevice "/:hdb/"
            IgnoreSelected "true"

           Ignore all hdb devices on any domain, but other block devices (eg. hda) will be collected.

       BlockDeviceFormat target|source
           If BlockDeviceFormat is set to target, the default, then the device name seen by the guest will be
           used for reporting metrics.  This corresponds to the "<target>" node in the XML definition of the
           domain.

           If BlockDeviceFormat is set to source, then metrics will be reported using the path of the source,
           e.g. an image file.  This corresponds to the "<source>" node in the XML definition of the domain.

           Example:

           If the domain XML have the following device defined:

             <disk type='block' device='disk'>
               <driver name='qemu' type='raw' cache='none' io='native' discard='unmap'/>
               <source dev='/var/lib/libvirt/images/image1.qcow2'/>
               <target dev='sda' bus='scsi'/>
               <boot order='2'/>
               <address type='drive' controller='0' bus='0' target='0' unit='0'/>
             </disk>

           Setting "BlockDeviceFormat target" will cause the type instance to be set to "sda".  Setting
           "BlockDeviceFormat source" will cause the type instance to be set to
           "var_lib_libvirt_images_image1.qcow2".

       BlockDeviceFormatBasename false|true
           The BlockDeviceFormatBasename controls whether the full path or the basename(1) of the source is
           being used as the type instance when BlockDeviceFormat is set to source. Defaults to false.

           Example:

           Assume the device path (source tag) is "/var/lib/libvirt/images/image1.qcow2".  Setting
           "BlockDeviceFormatBasename false" will cause the type instance to be set to
           "var_lib_libvirt_images_image1.qcow2".  Setting "BlockDeviceFormatBasename true" will cause the type
           instance to be set to "image1.qcow2".

       HostnameFormat name|uuid|hostname|...
           When the virt plugin logs data, it sets the hostname of the collected data according to this setting.
           The default is to use the guest name as provided by the hypervisor, which is equal to setting name.

           uuid means use the guest's UUID. This is useful if you want to track the same guest across
           migrations.

           hostname means to use the global Hostname setting, which is probably not useful on its own because
           all guests will appear to have the same name.

           You can also specify combinations of these fields. For example name uuid means to concatenate the
           guest name and UUID (with a literal colon character between, thus "foo:1234-1234-1234-1234").

           At the moment of writing (collectd-5.5), hostname string is limited to 62 characters. In case when
           combination of fields exceeds 62 characters, hostname will be truncated without a warning.

       InterfaceFormat name|address
           When the virt plugin logs interface data, it sets the name of the collected data according to this
           setting. The default is to use the path as provided by the hypervisor (the "dev" property of the
           target node), which is equal to setting name.

           address means use the interface's mac address. This is useful since the interface path might change
           between reboots of a guest or across migrations.

       PluginInstanceFormat name|uuid|none
           When the virt plugin logs data, it sets the plugin_instance of the collected data according to this
           setting. The default is to not set the plugin_instance.

           name means use the guest's name as provided by the hypervisor.  uuid means use the guest's UUID.

           You can also specify combinations of the name and uuid fields.  For example name uuid means to
           concatenate the guest name and UUID (with a literal colon character between, thus
           "foo:1234-1234-1234-1234").

   Plugin "vmem"
       The "vmem" plugin collects information about the usage of virtual memory.  Since the statistics provided
       by the Linux kernel are very detailed, they are collected very detailed. However, to get all the details,
       you have to switch them on manually. Most people just want an overview over, such as the number of pages
       read from swap space.

       Verbose true|false
           Enables verbose collection of information. This will start collecting page "actions", e. g. page
           allocations, (de)activations, steals and so on.  Part of these statistics are collected on a "per
           zone" basis.

   Plugin "vserver"
       This plugin doesn't have any options. VServer support is only available for Linux. It cannot yet be found
       in a vanilla kernel, though. To make use of this plugin you need a kernel that has VServer support built
       in, i. e. you need to apply the patches and compile your own kernel, which will then provide the
       /proc/virtual filesystem that is required by this plugin.

       The VServer homepage can be found at <http://linux-vserver.org/>.

       Note: The traffic collected by this plugin accounts for the amount of traffic passing a socket which
       might be a lot less than the actual on-wire traffic (e. g. due to headers and retransmission). If you
       want to collect on-wire traffic you could, for example, use the logging facilities of iptables to feed
       data for the guest IPs into the iptables plugin.

   Plugin "write_graphite"
       The "write_graphite" plugin writes data to Graphite, an open-source metrics storage and graphing project.
       The plugin connects to Carbon, the data layer of Graphite, via TCP or UDP and sends data via the "line
       based" protocol (per default using port 2003). The data will be sent in blocks of at most 1428 bytes to
       minimize the number of network packets.

       Synopsis:

        <Plugin write_graphite>
          <Node "example">
            Host "localhost"
            Port "2003"
            Protocol "tcp"
            LogSendErrors true
            Prefix "collectd"
          </Node>
        </Plugin>

       The configuration consists of one or more <Node Name> blocks. Inside the Node blocks, the following
       options are recognized:

       Host Address
           Hostname or address to connect to. Defaults to "localhost".

       Port Service
           Service name or port number to connect to. Defaults to 2003.

       Protocol String
           Protocol to use when connecting to Graphite. Defaults to "tcp".

       ReconnectInterval Seconds
           When set to non-zero, forces the connection to the Graphite backend to be closed and re-opend
           periodically. This behavior is desirable in environments where the connection to the Graphite backend
           is done through load balancers, for example. When set to zero, the default, the connetion is kept
           open for as long as possible.

       LogSendErrors false|true
           If set to true (the default), logs errors when sending data to Graphite.  If set to false, it will
           not log the errors. This is especially useful when using Protocol UDP since many times we want to use
           the "fire-and-forget" approach and logging errors fills syslog with unneeded messages.

       Prefix String
           When set, String is added in front of the host name. Dots and whitespace are not escaped in this
           string (see EscapeCharacter below).

       Postfix String
           When set, String is appended to the host name. Dots and whitespace are not escaped in this string
           (see EscapeCharacter below).

       EscapeCharacter Char
           Carbon uses the dot (".") as escape character and doesn't allow whitespace in the identifier. The
           EscapeCharacter option determines which character dots, whitespace and control characters are
           replaced with. Defaults to underscore ("_").

       StoreRates false|true
           If set to true (the default), convert counter values to rates. If set to false counter values are
           stored as is, i. e. as an increasing integer number.

       SeparateInstances false|true
           If set to true, the plugin instance and type instance will be in their own path component, for
           example "host.cpu.0.cpu.idle". If set to false (the default), the plugin and plugin instance (and
           likewise the type and type instance) are put into one component, for example "host.cpu-0.cpu-idle".

       AlwaysAppendDS false|true
           If set to true, append the name of the Data Source (DS) to the "metric" identifier. If set to false
           (the default), this is only done when there is more than one DS.

       PreserveSeparator false|true
           If set to false (the default) the "." (dot) character is replaced with EscapeCharacter. Otherwise, if
           set to true, the "." (dot) character is preserved, i.e. passed through.

       DropDuplicateFields false|true
           If set to true, detect and remove duplicate components in Graphite metric names. For example, the
           metric name  "host.load.load.shortterm" will be shortened to "host.load.shortterm".

   Plugin "write_log"
       The "write_log" plugin writes metrics as INFO log messages.

       This plugin supports two output formats: Graphite and JSON.

       Synopsis:

        <Plugin write_log>
          Format Graphite
        </Plugin>

       Format Format
           The output format to use. Can be one of "Graphite" or "JSON".

   Plugin "write_tsdb"
       The "write_tsdb" plugin writes data to OpenTSDB, a scalable open-source time series database. The plugin
       connects to a TSD, a masterless, no shared state daemon that ingests metrics and stores them in HBase.
       The plugin uses TCP over the "line based" protocol with a default port 4242. The data will be sent in
       blocks of at most 1428 bytes to minimize the number of network packets.

       Synopsis:

        <Plugin write_tsdb>
          <Node "example">
            Host "tsd-1.my.domain"
            Port "4242"
            HostTags "status=production"
          </Node>
        </Plugin>

       The configuration consists of one or more <Node Name> blocks. Inside the Node blocks, the following
       options are recognized:

       Host Address
           Hostname or address to connect to. Defaults to "localhost".

       Port Service
           Service name or port number to connect to. Defaults to 4242.

       HostTags String
           When set, HostTags is added to the end of the metric. It is intended to be used for name=value pairs
           that the TSD will tag the metric with. Dots and whitespace are not escaped in this string.

       StoreRates false|true
           If set to true, convert counter values to rates. If set to false (the default) counter values are
           stored as is, as an increasing integer number.

       AlwaysAppendDS false|true
           If set the true, append the name of the Data Source (DS) to the "metric" identifier. If set to false
           (the default), this is only done when there is more than one DS.

   Plugin "write_mongodb"
       The write_mongodb plugin will send values to MongoDB, a schema-less NoSQL database.

       Synopsis:

        <Plugin "write_mongodb">
          <Node "default">
            Host "localhost"
            Port "27017"
            Timeout 1000
            StoreRates true
          </Node>
        </Plugin>

       The plugin can send values to multiple instances of MongoDB by specifying one Node block for each
       instance. Within the Node blocks, the following options are available:

       Host Address
           Hostname or address to connect to. Defaults to "localhost".

       Port Service
           Service name or port number to connect to. Defaults to 27017.

       Timeout Milliseconds
           Set the timeout for each operation on MongoDB to Timeout milliseconds.  Setting this option to zero
           means no timeout, which is the default.

       StoreRates false|true
           If set to true (the default), convert counter values to rates. If set to false counter values are
           stored as is, i.e. as an increasing integer number.

       Database Database
       User User
       Password Password
           Sets the information used when authenticating to a MongoDB database. The fields are optional (in
           which case no authentication is attempted), but if you want to use authentication all three fields
           must be set.

   Plugin "write_prometheus"
       The write_prometheus plugin implements a tiny webserver that can be scraped using Prometheus.

       Options:

       Port Port
           Port the embedded webserver should listen on. Defaults to 9103.

       StalenessDelta Seconds
           Time in seconds after which Prometheus considers a metric "stale" if it hasn't seen any update for
           it. This value must match the setting in Prometheus.  It defaults to 300 seconds (5 minutes), same as
           Prometheus.

           Background:

           Prometheus has a global setting, "StalenessDelta", which controls after which time a metric without
           updates is considered "stale". This setting effectively puts an upper limit on the interval in which
           metrics are reported.

           When the write_prometheus plugin encounters a metric with an interval exceeding this limit, it will
           inform you, the user, and provide the metric to Prometheus without a timestamp. That causes
           Prometheus to consider the metric "fresh" each time it is scraped, with the time of the scrape being
           considered the time of the update. The result is that there appear more datapoints in Prometheus than
           were actually created, but at least the metric doesn't disappear periodically.

   Plugin "write_http"
       This output plugin submits values to an HTTP server using POST requests and encoding metrics with JSON or
       using the "PUTVAL" command described in collectd-unixsock(5).

       Synopsis:

        <Plugin "write_http">
          <Node "example">
            URL "http://example.com/post-collectd"
            User "collectd"
            Password "weCh3ik0"
            Format JSON
          </Node>
        </Plugin>

       The plugin can send values to multiple HTTP servers by specifying one <Node Name> block for each server.
       Within each Node block, the following options are available:

       URL URL
           URL to which the values are submitted to. Mandatory.

       User Username
           Optional user name needed for authentication.

       Password Password
           Optional password needed for authentication.

       VerifyPeer true|false
           Enable or disable peer SSL certificate verification. See <http://curl.haxx.se/docs/sslcerts.html> for
           details. Enabled by default.

       VerifyHost true|false
           Enable or disable peer host name verification. If enabled, the plugin checks if the "Common Name" or
           a "Subject Alternate Name" field of the SSL certificate matches the host name provided by the URL
           option. If this identity check fails, the connection is aborted. Obviously, only works when
           connecting to a SSL enabled server. Enabled by default.

       CACert File
           File that holds one or more SSL certificates. If you want to use HTTPS you will possibly need this
           option. What CA certificates come bundled with "libcurl" and are checked by default depends on the
           distribution you use.

       CAPath Directory
           Directory holding one or more CA certificate files. You can use this if for some reason all the
           needed CA certificates aren't in the same file and can't be pointed to using the CACert option.
           Requires "libcurl" to be built against OpenSSL.

       ClientKey File
           File that holds the private key in PEM format to be used for certificate-based authentication.

       ClientCert File
           File that holds the SSL certificate to be used for certificate-based authentication.

       ClientKeyPass Password
           Password required to load the private key in ClientKey.

       Header Header
           A HTTP header to add to the request.  Multiple headers are added if this option is specified more
           than once.  Example:

             Header "X-Custom-Header: custom_value"

       SSLVersion SSLv2|SSLv3|TLSv1|TLSv1_0|TLSv1_1|TLSv1_2
           Define which SSL protocol version must be used. By default "libcurl" will attempt to figure out the
           remote SSL protocol version. See curl_easy_setopt(3) for more details.

       Format Command|JSON|KAIROSDB
           Format of the output to generate. If set to Command, will create output that is understood by the
           Exec and UnixSock plugins. When set to JSON, will create output in the JavaScript Object Notation
           (JSON). When set to KAIROSDB , will create output in the KairosDB format.

           Defaults to Command.

       Metrics true|false
           Controls whether metrics are POSTed to this location. Defaults to true.

       Notifications false|true
           Controls whether notifications are POSTed to this location. Defaults to false.

       StoreRates true|false
           If set to true, convert counter values to rates. If set to false (the default) counter values are
           stored as is, i.e. as an increasing integer number.

       BufferSize Bytes
           Sets the send buffer size to Bytes. By increasing this buffer, less HTTP requests will be generated,
           but more metrics will be batched / metrics are cached for longer before being sent, introducing
           additional delay until they are available on the server side. Bytes must be at least 1024 and cannot
           exceed the size of an "int", i.e. 2 GByte.  Defaults to 4096.

       LowSpeedLimit Bytes per Second
           Sets the minimal transfer rate in Bytes per Second below which the connection with the HTTP server
           will be considered too slow and aborted. All the data submitted over this connection will probably be
           lost. Defaults to 0, which means no minimum transfer rate is enforced.

       Timeout Timeout
           Sets the maximum time in milliseconds given for HTTP POST operations to complete. When this limit is
           reached, the POST operation will be aborted, and all the data in the current send buffer will
           probably be lost. Defaults to 0, which means the connection never times out.

       LogHttpError false|true
           Enables printing of HTTP error code to log. Turned off by default.

           The "write_http" plugin regularly submits the collected values to the HTTP server. How frequently
           this happens depends on how much data you are collecting and the size of BufferSize. The optimal
           value to set Timeout to is slightly below this interval, which you can estimate by monitoring the
           network traffic between collectd and the HTTP server.

   Plugin "write_kafka"
       The write_kafka plugin will send values to a Kafka topic, a distributed queue.  Synopsis:

        <Plugin "write_kafka">
          Property "metadata.broker.list" "broker1:9092,broker2:9092"
          <Topic "collectd">
            Format JSON
          </Topic>
        </Plugin>

       The following options are understood by the write_kafka plugin:

       <Topic Name>
           The plugin's configuration consists of one or more Topic blocks. Each block is given a unique Name
           and specifies one kafka producer.  Inside the Topic block, the following per-topic options are
           understood:

           Property String String
               Configure the named property for the current topic. Properties are forwarded to the kafka
               producer library librdkafka.

           Key String
               Use the specified string as a partitioning key for the topic. Kafka breaks topic into partitions
               and guarantees that for a given topology, the same consumer will be used for a specific key. The
               special (case insensitive) string Random can be used to specify that an arbitrary partition
               should be used.

           Format Command|JSON|Graphite
               Selects the format in which messages are sent to the broker. If set to Command (the default),
               values are sent as "PUTVAL" commands which are identical to the syntax used by the Exec and
               UnixSock plugins.

               If set to JSON, the values are encoded in the JavaScript Object Notation, an easy and straight
               forward exchange format.

               If set to Graphite, values are encoded in the Graphite format, which is "<metric> <value>
               <timestamp>\n".

           StoreRates true|false
               Determines whether or not "COUNTER", "DERIVE" and "ABSOLUTE" data sources are converted to a rate
               (i.e. a "GAUGE" value). If set to false (the default), no conversion is performed. Otherwise the
               conversion is performed using the internal value cache.

               Please note that currently this option is only used if the Format option has been set to JSON.

           GraphitePrefix (Format=Graphite only)
               A prefix can be added in the metric name when outputting in the Graphite format. It's added
               before the Host name.  Metric name will be "<prefix><host><postfix><plugin><type><name>"

           GraphitePostfix (Format=Graphite only)
               A postfix can be added in the metric name when outputting in the Graphite format. It's added
               after the Host name.  Metric name will be "<prefix><host><postfix><plugin><type><name>"

           GraphiteEscapeChar (Format=Graphite only)
               Specify a character to replace dots (.) in the host part of the metric name.  In Graphite metric
               name, dots are used as separators between different metric parts (host, plugin, type).  Default
               is "_" (Underscore).

           GraphiteSeparateInstances false|true
               If set to true, the plugin instance and type instance will be in their own path component, for
               example "host.cpu.0.cpu.idle". If set to false (the default), the plugin and plugin instance (and
               likewise the type and type instance) are put into one component, for example
               "host.cpu-0.cpu-idle".

           GraphiteAlwaysAppendDS true|false
               If set to true, append the name of the Data Source (DS) to the "metric" identifier. If set to
               false (the default), this is only done when there is more than one DS.

           GraphitePreserveSeparator false|true
               If set to false (the default) the "." (dot) character is replaced with GraphiteEscapeChar.
               Otherwise, if set to true, the "." (dot) character is preserved, i.e. passed through.

           StoreRates true|false
               If set to true (the default), convert counter values to rates. If set to false counter values are
               stored as is, i.e. as an increasing integer number.

               This will be reflected in the "ds_type" tag: If StoreRates is enabled, converted values will have
               "rate" appended to the data source type, e.g.  "ds_type:derive:rate".

       Property String String
           Configure the kafka producer through properties, you almost always will want to set
           metadata.broker.list to your Kafka broker list.

   Plugin "write_redis"
       The write_redis plugin submits values to Redis, a data structure server.

       Synopsis:

         <Plugin "write_redis">
           <Node "example">
               Host "localhost"
               Port "6379"
               Timeout 1000
               Prefix "collectd/"
               Database 1
               MaxSetSize -1
               StoreRates true
           </Node>
         </Plugin>

       Values are submitted to Sorted Sets, using the metric name as the key, and the timestamp as the score.
       Retrieving a date range can then be done using the "ZRANGEBYSCORE" Redis command. Additionally, all the
       identifiers of these Sorted Sets are kept in a Set called "collectd/values" (or "${prefix}/values" if the
       Prefix option was specified) and can be retrieved using the "SMEMBERS" Redis command. You can specify the
       database to use with the Database parameter (default is 0). See <http://redis.io/commands#sorted_set> and
       <http://redis.io/commands#set> for details.

       The information shown in the synopsis above is the default configuration which is used by the plugin if
       no configuration is present.

       The plugin can send values to multiple instances of Redis by specifying one Node block for each instance.
       Within the Node blocks, the following options are available:

       Node Nodename
           The Node block identifies a new Redis node, that is a new Redis instance running on a specified host
           and port. The node name is a canonical identifier which is used as plugin instance. It is limited to
           51 characters in length.

       Host Hostname
           The Host option is the hostname or IP-address where the Redis instance is running on.

       Port Port
           The Port option is the TCP port on which the Redis instance accepts connections. Either a service
           name of a port number may be given. Please note that numerical port numbers must be given as a
           string, too.

       Timeout Milliseconds
           The Timeout option sets the socket connection timeout, in milliseconds.

       Prefix Prefix
           Prefix used when constructing the name of the Sorted Sets and the Set containing all metrics.
           Defaults to "collectd/", so metrics will have names like "collectd/cpu-0/cpu-user". When setting this
           to something different, it is recommended but not required to include a trailing slash in Prefix.

       Database Index
           This index selects the redis database to use for writing operations. Defaults to 0.

       MaxSetSize Items
           The MaxSetSize option limits the number of items that the Sorted Sets can hold. Negative values for
           Items sets no limit, which is the default behavior.

       StoreRates true|false
           If set to true (the default), convert counter values to rates. If set to false counter values are
           stored as is, i.e. as an increasing integer number.

   Plugin "write_riemann"
       The write_riemann plugin will send values to Riemann, a powerful stream aggregation and monitoring
       system. The plugin sends Protobuf encoded data to Riemann using UDP packets.

       Synopsis:

        <Plugin "write_riemann">
          <Node "example">
            Host "localhost"
            Port "5555"
            Protocol UDP
            StoreRates true
            AlwaysAppendDS false
            TTLFactor 2.0
          </Node>
          Tag "foobar"
          Attribute "foo" "bar"
        </Plugin>

       The following options are understood by the write_riemann plugin:

       <Node Name>
           The plugin's configuration consists of one or more Node blocks. Each block is given a unique Name and
           specifies one connection to an instance of Riemann. Indise the Node block, the following per-
           connection options are understood:

           Host Address
               Hostname or address to connect to. Defaults to "localhost".

           Port Service
               Service name or port number to connect to. Defaults to 5555.

           Protocol UDP|TCP|TLS
               Specify the protocol to use when communicating with Riemann. Defaults to TCP.

           TLSCertFile Path
               When using the TLS protocol, path to a PEM certificate to present to remote host.

           TLSCAFile Path
               When using the TLS protocol, path to a PEM CA certificate to use to validate the remote hosts's
               identity.

           TLSKeyFile Path
               When using the TLS protocol, path to a PEM private key associated with the certificate defined by
               TLSCertFile.

           Batch true|false
               If set to true and Protocol is set to TCP, events will be batched in memory and flushed at
               regular intervals or when BatchMaxSize is exceeded.

               Notifications are not batched and sent as soon as possible.

               When enabled, it can occur that events get processed by the Riemann server close to or after
               their expiration time. Tune the TTLFactor and BatchMaxSize settings according to the amount of
               values collected, if this is an issue.

               Defaults to true

           BatchMaxSize size
               Maximum payload size for a riemann packet. Defaults to 8192

           BatchFlushTimeout seconds
               Maximum amount of seconds to wait in between to batch flushes.  No timeout by default.

           StoreRates true|false
               If set to true (the default), convert counter values to rates. If set to false counter values are
               stored as is, i.e. as an increasing integer number.

               This will be reflected in the "ds_type" tag: If StoreRates is enabled, converted values will have
               "rate" appended to the data source type, e.g.  "ds_type:derive:rate".

           AlwaysAppendDS false|true
               If set to true, append the name of the Data Source (DS) to the "service", i.e. the field that,
               together with the "host" field, uniquely identifies a metric in Riemann. If set to false (the
               default), this is only done when there is more than one DS.

           TTLFactor Factor
               Riemann events have a Time to Live (TTL) which specifies how long each event is considered
               active. collectd populates this field based on the metrics interval setting. This setting
               controls the factor with which the interval is multiplied to set the TTL. The default value is
               2.0. Unless you know exactly what you're doing, you should only increase this setting from its
               default value.

           Notifications false|true
               If set to true, create riemann events for notifications. This is true by default. When processing
               thresholds from write_riemann, it might prove useful to avoid getting notification events.

           CheckThresholds false|true
               If set to true, attach state to events based on thresholds defined in the Threshold plugin.
               Defaults to false.

           EventServicePrefix String
               Add the given string as a prefix to the event service name.  If EventServicePrefix not set or set
               to an empty string (""), no prefix will be used.

       Tag String
           Add the given string as an additional tag to the metric being sent to Riemann.

       Attribute String String
           Consider the two given strings to be the key and value of an additional attribute for each metric
           being sent out to Riemann.

   Plugin "write_sensu"
       The write_sensu plugin will send values to Sensu, a powerful stream aggregation and monitoring system.
       The plugin sends JSON encoded data to a local Sensu client using a TCP socket.

       At the moment, the write_sensu plugin does not send over a collectd_host parameter so it is not possible
       to use one collectd instance as a gateway for others. Each collectd host must pair with one Sensu client.

       Synopsis:

        <Plugin "write_sensu">
          <Node "example">
            Host "localhost"
            Port "3030"
            StoreRates true
            AlwaysAppendDS false
            MetricHandler "influx"
            MetricHandler "default"
            NotificationHandler "flapjack"
            NotificationHandler "howling_monkey"
            Notifications true
          </Node>
          Tag "foobar"
          Attribute "foo" "bar"
        </Plugin>

       The following options are understood by the write_sensu plugin:

       <Node Name>
           The plugin's configuration consists of one or more Node blocks. Each block is given a unique Name and
           specifies one connection to an instance of Sensu. Inside the Node block, the following per-connection
           options are understood:

           Host Address
               Hostname or address to connect to. Defaults to "localhost".

           Port Service
               Service name or port number to connect to. Defaults to 3030.

           StoreRates true|false
               If set to true (the default), convert counter values to rates. If set to false counter values are
               stored as is, i.e. as an increasing integer number.

               This will be reflected in the "collectd_data_source_type" tag: If StoreRates is enabled,
               converted values will have "rate" appended to the data source type, e.g.
               "collectd_data_source_type:derive:rate".

           AlwaysAppendDS false|true
               If set the true, append the name of the Data Source (DS) to the "service", i.e. the field that,
               together with the "host" field, uniquely identifies a metric in Sensu. If set to false (the
               default), this is only done when there is more than one DS.

           Notifications false|true
               If set to true, create Sensu events for notifications. This is false by default. At least one of
               Notifications or Metrics should be enabled.

           Metrics false|true
               If set to true, create Sensu events for metrics. This is false by default. At least one of
               Notifications or Metrics should be enabled.

           Separator String
               Sets the separator for Sensu metrics name or checks. Defaults to "/".

           MetricHandler String
               Add a handler that will be set when metrics are sent to Sensu. You can add several of them, one
               per line. Defaults to no handler.

           NotificationHandler String
               Add a handler that will be set when notifications are sent to Sensu. You can add several of them,
               one per line. Defaults to no handler.

           EventServicePrefix String
               Add the given string as a prefix to the event service name.  If EventServicePrefix not set or set
               to an empty string (""), no prefix will be used.

       Tag String
           Add the given string as an additional tag to the metric being sent to Sensu.

       Attribute String String
           Consider the two given strings to be the key and value of an additional attribute for each metric
           being sent out to Sensu.

   Plugin "xencpu"
       This plugin collects metrics of hardware CPU load for machine running Xen hypervisor. Load is calculated
       from 'idle time' value, provided by Xen.  Result is reported using the "percent" type, for each CPU
       (core).

       This plugin doesn't have any options (yet).

   Plugin "zookeeper"
       The zookeeper plugin will collect statistics from a Zookeeper server using the mntr command.  It requires
       Zookeeper 3.4.0+ and access to the client port.

       Synopsis:

        <Plugin "zookeeper">
          Host "127.0.0.1"
          Port "2181"
        </Plugin>

       Host Address
           Hostname or address to connect to. Defaults to "localhost".

       Port Service
           Service name or port number to connect to. Defaults to 2181.

THRESHOLD CONFIGURATION

       Starting with version 4.3.0 collectd has support for monitoring. By that we mean that the values are not
       only stored or sent somewhere, but that they are judged and, if a problem is recognized, acted upon. The
       only action collectd takes itself is to generate and dispatch a "notification". Plugins can register to
       receive notifications and perform appropriate further actions.

       Since systems and what you expect them to do differ a lot, you can configure thresholds for your values
       freely. This gives you a lot of flexibility but also a lot of responsibility.

       Every time a value is out of range a notification is dispatched. This means that the idle percentage of
       your CPU needs to be less then the configured threshold only once for a notification to be generated.
       There's no such thing as a moving average or similar - at least not now.

       Also, all values that match a threshold are considered to be relevant or "interesting". As a consequence
       collectd will issue a notification if they are not received for Timeout iterations. The Timeout
       configuration option is explained in section "GLOBAL OPTIONS". If, for example, Timeout is set to "2"
       (the default) and some hosts sends it's CPU statistics to the server every 60 seconds, a notification
       will be dispatched after about 120 seconds. It may take a little longer because the timeout is checked
       only once each Interval on the server.

       When a value comes within range again or is received after it was missing, an "OKAY-notification" is
       dispatched.

       Here is a configuration example to get you started. Read below for more information.

        <Plugin threshold>
          <Type "foo">
            WarningMin    0.00
            WarningMax 1000.00
            FailureMin    0.00
            FailureMax 1200.00
            Invert false
            Instance "bar"
          </Type>

          <Plugin "interface">
            Instance "eth0"
            <Type "if_octets">
              FailureMax 10000000
              DataSource "rx"
            </Type>
          </Plugin>

          <Host "hostname">
            <Type "cpu">
              Instance "idle"
              FailureMin 10
            </Type>

            <Plugin "memory">
              <Type "memory">
                Instance "cached"
                WarningMin 100000000
              </Type>
            </Plugin>
          </Host>
        </Plugin>

       There are basically two types of configuration statements: The "Host", "Plugin", and "Type" blocks select
       the value for which a threshold should be configured. The "Plugin" and "Type" blocks may be specified
       further using the "Instance" option. You can combine the block by nesting the blocks, though they must be
       nested in the above order, i. e. "Host" may contain either "Plugin" and "Type" blocks, "Plugin" may only
       contain "Type" blocks and "Type" may not contain other blocks. If multiple blocks apply to the same value
       the most specific block is used.

       The other statements specify the threshold to configure. They must be included in a "Type" block.
       Currently the following statements are recognized:

       FailureMax Value
       WarningMax Value
           Sets the upper bound of acceptable values. If unset defaults to positive infinity. If a value is
           greater than FailureMax a FAILURE notification will be created. If the value is greater than
           WarningMax but less than (or equal to) FailureMax a WARNING notification will be created.

       FailureMin Value
       WarningMin Value
           Sets the lower bound of acceptable values. If unset defaults to negative infinity. If a value is less
           than FailureMin a FAILURE notification will be created. If the value is less than WarningMin but
           greater than (or equal to) FailureMin a WARNING notification will be created.

       DataSource DSName
           Some data sets have more than one "data source". Interesting examples are the "if_octets" data set,
           which has received ("rx") and sent ("tx") bytes and the "disk_ops" data set, which holds "read" and
           "write" operations. The system load data set, "load", even has three data sources: "shortterm",
           "midterm", and "longterm".

           Normally, all data sources are checked against a configured threshold. If this is undesirable, or if
           you want to specify different limits for each data source, you can use the DataSource option to have
           a threshold apply only to one data source.

       Invert true|false
           If set to true the range of acceptable values is inverted, i. e.  values between FailureMin and
           FailureMax (WarningMin and WarningMax) are not okay. Defaults to false.

       Persist true|false
           Sets how often notifications are generated. If set to true one notification will be generated for
           each value that is out of the acceptable range. If set to false (the default) then a notification is
           only generated if a value is out of range but the previous value was okay.

           This applies to missing values, too: If set to true a notification about a missing value is generated
           once every Interval seconds. If set to false only one such notification is generated until the value
           appears again.

       Percentage true|false
           If set to true, the minimum and maximum values given are interpreted as percentage value, relative to
           the other data sources. This is helpful for example for the "df" type, where you may want to issue a
           warning when less than 5 % of the total space is available. Defaults to false.

       Hits Number
           Delay creating the notification until the threshold has been passed Number times. When a notification
           has been generated, or when a subsequent value is inside the threshold, the counter is reset. If, for
           example, a value is collected once every 10 seconds and Hits is set to 3, a notification will be
           dispatched at most once every 30 seconds.

           This is useful when short bursts are not a problem. If, for example, 100% CPU usage for up to a
           minute is normal (and data is collected every 10 seconds), you could set Hits to 6 to account for
           this.

       Hysteresis Number
           When set to non-zero, a hysteresis value is applied when checking minimum and maximum bounds. This is
           useful for values that increase slowly and fluctuate a bit while doing so. When these values come
           close to the threshold, they may "flap", i.e. switch between failure / warning case and okay case
           repeatedly.

           If, for example, the threshold is configures as

             WarningMax 100.0
             Hysteresis 1.0

           then a Warning notification is created when the value exceeds 101 and the corresponding Okay
           notification is only created once the value falls below 99, thus avoiding the "flapping".

FILTER CONFIGURATION

       Starting with collectd 4.6 there is a powerful filtering infrastructure implemented in the daemon. The
       concept has mostly been copied from ip_tables, the packet filter infrastructure for Linux. We'll use a
       similar terminology, so that users that are familiar with iptables feel right at home.

   Terminology
       The following are the terms used in the remainder of the filter configuration documentation. For an
       ASCII-art schema of the mechanism, see "General structure" below.

       Match
           A match is a criteria to select specific values. Examples are, of course, the name of the value or
           it's current value.

           Matches are implemented in plugins which you have to load prior to using the match. The name of such
           plugins starts with the "match_" prefix.

       Target
           A target is some action that is to be performed with data. Such actions could, for example, be to
           change part of the value's identifier or to ignore the value completely.

           Some of these targets are built into the daemon, see "Built-in targets" below. Other targets are
           implemented in plugins which you have to load prior to using the target. The name of such plugins
           starts with the "target_" prefix.

       Rule
           The combination of any number of matches and at least one target is called a rule. The target actions
           will be performed for all values for which all matches apply. If the rule does not have any matches
           associated with it, the target action will be performed for all values.

       Chain
           A chain is a list of rules and possibly default targets. The rules are tried in order and if one
           matches, the associated target will be called. If a value is handled by a rule, it depends on the
           target whether or not any subsequent rules are considered or if traversal of the chain is aborted,
           see "Flow control" below. After all rules have been checked, the default targets will be executed.

   General structure
       The following shows the resulting structure:

        +---------+
        ! Chain   !
        +---------+
             !
             V
        +---------+  +---------+  +---------+  +---------+
        ! Rule    !->! Match   !->! Match   !->! Target  !
        +---------+  +---------+  +---------+  +---------+
             !
             V
        +---------+  +---------+  +---------+
        ! Rule    !->! Target  !->! Target  !
        +---------+  +---------+  +---------+
             !
             V
             :
             :
             !
             V
        +---------+  +---------+  +---------+
        ! Rule    !->! Match   !->! Target  !
        +---------+  +---------+  +---------+
             !
             V
        +---------+
        ! Default !
        ! Target  !
        +---------+

   Flow control
       There are four ways to control which way a value takes through the filter mechanism:

       jump
           The built-in jump target can be used to "call" another chain, i. e.  process the value with another
           chain. When the called chain finishes, usually the next target or rule after the jump is executed.

       stop
           The stop condition, signaled for example by the built-in target stop, causes all processing of the
           value to be stopped immediately.

       return
           Causes processing in the current chain to be aborted, but processing of the value generally will
           continue. This means that if the chain was called via Jump, the next target or rule after the jump
           will be executed. If the chain was not called by another chain, control will be returned to the
           daemon and it may pass the value to another chain.

       continue
           Most targets will signal the continue condition, meaning that processing should continue normally.
           There is no special built-in target for this condition.

   Synopsis
       The configuration reflects this structure directly:

        PostCacheChain "PostCache"
        <Chain "PostCache">
          <Rule "ignore_mysql_show">
            <Match "regex">
              Plugin "^mysql$"
              Type "^mysql_command$"
              TypeInstance "^show_"
            </Match>
            <Target "stop">
            </Target>
          </Rule>
          <Target "write">
            Plugin "rrdtool"
          </Target>
        </Chain>

       The above configuration example will ignore all values where the plugin field is "mysql", the type is
       "mysql_command" and the type instance begins with "show_". All other values will be sent to the "rrdtool"
       write plugin via the default target of the chain. Since this chain is run after the value has been added
       to the cache, the MySQL "show_*" command statistics will be available via the "unixsock" plugin.

   List of configuration options
       PreCacheChain ChainName
       PostCacheChain ChainName
           Configure the name of the "pre-cache chain" and the "post-cache chain". The argument is the name of a
           chain that should be executed before and/or after the values have been added to the cache.

           To understand the implications, it's important you know what is going on inside collectd. The
           following diagram shows how values are passed from the read-plugins to the write-plugins:

              +---------------+
              !  Read-Plugin  !
              +-------+-------+
                      !
            + - - - - V - - - - +
            : +---------------+ :
            : !   Pre-Cache   ! :
            : !     Chain     ! :
            : +-------+-------+ :
            :         !         :
            :         V         :
            : +-------+-------+ :  +---------------+
            : !     Cache     !--->!  Value Cache  !
            : !     insert    ! :  +---+---+-------+
            : +-------+-------+ :      !   !
            :         !   ,------------'   !
            :         V   V     :          V
            : +-------+---+---+ :  +-------+-------+
            : !  Post-Cache   +--->! Write-Plugins !
            : !     Chain     ! :  +---------------+
            : +---------------+ :
            :                   :
            :  dispatch values  :
            + - - - - - - - - - +

           After the values are passed from the "read" plugins to the dispatch functions, the pre-cache chain is
           run first. The values are added to the internal cache afterwards. The post-cache chain is run after
           the values have been added to the cache. So why is it such a huge deal if chains are run before or
           after the values have been added to this cache?

           Targets that change the identifier of a value list should be executed before the values are added to
           the cache, so that the name in the cache matches the name that is used in the "write" plugins. The
           "unixsock" plugin, too, uses this cache to receive a list of all available values. If you change the
           identifier after the value list has been added to the cache, this may easily lead to confusion, but
           it's not forbidden of course.

           The cache is also used to convert counter values to rates. These rates are, for example, used by the
           "value" match (see below). If you use the rate stored in the cache before the new value is added, you
           will use the old, previous rate. Write plugins may use this rate, too, see the "csv" plugin, for
           example.  The "unixsock" plugin uses these rates too, to implement the "GETVAL" command.

           Last but not last, the stop target makes a difference: If the pre-cache chain returns the stop
           condition, the value will not be added to the cache and the post-cache chain will not be run.

       Chain Name
           Adds a new chain with a certain name. This name can be used to refer to a specific chain, for example
           to jump to it.

           Within the Chain block, there can be Rule blocks and Target blocks.

       Rule [Name]
           Adds a new rule to the current chain. The name of the rule is optional and currently has no meaning
           for the daemon.

           Within the Rule block, there may be any number of Match blocks and there must be at least one Target
           block.

       Match Name
           Adds a match to a Rule block. The name specifies what kind of match should be performed. Available
           matches depend on the plugins that have been loaded.

           The arguments inside the Match block are passed to the plugin implementing the match, so which
           arguments are valid here depends on the plugin being used.  If you do not need any to pass any
           arguments to a match, you can use the shorter syntax:

            Match "foobar"

           Which is equivalent to:

            <Match "foobar">
            </Match>

       Target Name
           Add a target to a rule or a default target to a chain. The name specifies what kind of target is to
           be added. Which targets are available depends on the plugins being loaded.

           The arguments inside the Target block are passed to the plugin implementing the target, so which
           arguments are valid here depends on the plugin being used.  If you do not need any to pass any
           arguments to a target, you can use the shorter syntax:

            Target "stop"

           This is the same as writing:

            <Target "stop">
            </Target>

   Built-in targets
       The following targets are built into the core daemon and therefore need no plugins to be loaded:

       return
           Signals the "return" condition, see the "Flow control" section above. This causes the current chain
           to stop processing the value and returns control to the calling chain. The calling chain will
           continue processing targets and rules just after the jump target (see below). This is very similar to
           the RETURN target of iptables, see iptables(8).

           This target does not have any options.

           Example:

            Target "return"

       stop
           Signals the "stop" condition, see the "Flow control" section above. This causes processing of the
           value to be aborted immediately. This is similar to the DROP target of iptables, see iptables(8).

           This target does not have any options.

           Example:

            Target "stop"

       write
           Sends the value to "write" plugins.

           Available options:

           Plugin Name
               Name of the write plugin to which the data should be sent. This option may be given multiple
               times to send the data to more than one write plugin. If the plugin supports multiple instances,
               the plugin's instance(s) must also be specified.

           If no plugin is explicitly specified, the values will be sent to all available write plugins.

           Single-instance plugin example:

            <Target "write">
              Plugin "rrdtool"
            </Target>

           Multi-instance plugin example:

            <Plugin "write_graphite">
              <Node "foo">
              ...
              </Node>
              <Node "bar">
              ...
              </Node>
            </Plugin>
             ...
            <Target "write">
              Plugin "write_graphite/foo"
            </Target>

       jump
           Starts processing the rules of another chain, see "Flow control" above. If the end of that chain is
           reached, or a stop condition is encountered, processing will continue right after the jump target,
           i. e. with the next target or the next rule. This is similar to the -j command line option of
           iptables, see iptables(8).

           Available options:

           Chain Name
               Jumps to the chain Name. This argument is required and may appear only once.

           Example:

            <Target "jump">
              Chain "foobar"
            </Target>

   Available matches
       regex
           Matches a value using regular expressions.

           Available options:

           Host Regex
           Plugin Regex
           PluginInstance Regex
           Type Regex
           TypeInstance Regex
           MetaData String Regex
               Match values where the given regular expressions match the various fields of the identifier of a
               value. If multiple regular expressions are given, all regexen must match for a value to match.

           Invert false|true
               When set to true, the result of the match is inverted, i.e. all value lists where all regular
               expressions apply are not matched, all other value lists are matched. Defaults to false.

           Example:

            <Match "regex">
              Host "customer[0-9]+"
              Plugin "^foobar$"
            </Match>

       timediff
           Matches values that have a time which differs from the time on the server.

           This match is mainly intended for servers that receive values over the "network" plugin and write
           them to disk using the "rrdtool" plugin. RRDtool is very sensitive to the timestamp used when
           updating the RRD files. In particular, the time must be ever increasing. If a misbehaving client
           sends one packet with a timestamp far in the future, all further packets with a correct time will be
           ignored because of that one packet. What's worse, such corrupted RRD files are hard to fix.

           This match lets one match all values outside a specified time range (relative to the server's time),
           so you can use the stop target (see below) to ignore the value, for example.

           Available options:

           Future Seconds
               Matches all values that are ahead of the server's time by Seconds or more seconds. Set to zero
               for no limit. Either Future or Past must be non-zero.

           Past Seconds
               Matches all values that are behind of the server's time by Seconds or more seconds. Set to zero
               for no limit. Either Future or Past must be non-zero.

           Example:

            <Match "timediff">
              Future  300
              Past   3600
            </Match>

           This example matches all values that are five minutes or more ahead of the server or one hour (or
           more) lagging behind.

       value
           Matches the actual value of data sources against given minimum / maximum values. If a data-set
           consists of more than one data-source, all data-sources must match the specified ranges for a
           positive match.

           Available options:

           Min Value
               Sets the smallest value which still results in a match. If unset, behaves like negative infinity.

           Max Value
               Sets the largest value which still results in a match. If unset, behaves like positive infinity.

           Invert true|false
               Inverts the selection. If the Min and Max settings result in a match, no-match is returned and
               vice versa. Please note that the Invert setting only effects how Min and Max are applied to a
               specific value. Especially the DataSource and Satisfy settings (see below) are not inverted.

           DataSource DSName [DSName ...]
               Select one or more of the data sources. If no data source is configured, all data sources will be
               checked. If the type handled by the match does not have a data source of the specified name(s),
               this will always result in no match (independent of the Invert setting).

           Satisfy Any|All
               Specifies how checking with several data sources is performed. If set to Any, the match succeeds
               if one of the data sources is in the configured range. If set to All the match only succeeds if
               all data sources are within the configured range. Default is All.

               Usually All is used for positive matches, Any is used for negative matches. This means that with
               All you usually check that all values are in a "good" range, while with Any you check if any
               value is within a "bad" range (or outside the "good" range).

           Either Min or Max, but not both, may be unset.

           Example:

            # Match all values smaller than or equal to 100. Matches only if all data
            # sources are below 100.
            <Match "value">
              Max 100
              Satisfy "All"
            </Match>

            # Match if the value of any data source is outside the range of 0 - 100.
            <Match "value">
              Min   0
              Max 100
              Invert true
              Satisfy "Any"
            </Match>

       empty_counter
           Matches all values with one or more data sources of type COUNTER and where all counter values are
           zero. These counters usually never increased since they started existing (and are therefore
           uninteresting), or got reset recently or overflowed and you had really, really bad luck.

           Please keep in mind that ignoring such counters can result in confusing behavior: Counters which
           hardly ever increase will be zero for long periods of time. If the counter is reset for some reason
           (machine or service restarted, usually), the graph will be empty (NAN) for a long time. People may
           not understand why.

       hashed
           Calculates a hash value of the host name and matches values according to that hash value. This makes
           it possible to divide all hosts into groups and match only values that are in a specific group. The
           intended use is in load balancing, where you want to handle only part of all data and leave the rest
           for other servers.

           The hashing function used tries to distribute the hosts evenly. First, it calculates a 32 bit hash
           value using the characters of the hostname:

             hash_value = 0;
             for (i = 0; host[i] != 0; i++)
               hash_value = (hash_value * 251) + host[i];

           The constant 251 is a prime number which is supposed to make this hash value more random. The code
           then checks the group for this host according to the Total and Match arguments:

             if ((hash_value % Total) == Match)
               matches;
             else
               does not match;

           Please note that when you set Total to two (i. e. you have only two groups), then the least
           significant bit of the hash value will be the XOR of all least significant bits in the host name. One
           consequence is that when you have two hosts, "server0.example.com" and "server1.example.com", where
           the host name differs in one digit only and the digits differ by one, those hosts will never end up
           in the same group.

           Available options:

           Match Match Total
               Divide the data into Total groups and match all hosts in group Match as described above. The
               groups are numbered from zero, i. e. Match must be smaller than Total. Total must be at least
               one, although only values greater than one really do make any sense.

               You can repeat this option to match multiple groups, for example:

                 Match 3 7
                 Match 5 7

               The above config will divide the data into seven groups and match groups three and five. One use
               would be to keep every value on two hosts so that if one fails the missing data can later be
               reconstructed from the second host.

           Example:

            # Operate on the pre-cache chain, so that ignored values are not even in the
            # global cache.
            <Chain "PreCache">
              <Rule>
                <Match "hashed">
                  # Divide all received hosts in seven groups and accept all hosts in
                  # group three.
                  Match 3 7
                </Match>
                # If matched: Return and continue.
                Target "return"
              </Rule>
              # If not matched: Return and stop.
              Target "stop"
            </Chain>

   Available targets
       notification
           Creates and dispatches a notification.

           Available options:

           Message String
               This required option sets the message of the notification. The following placeholders will be
               replaced by an appropriate value:

               %{host}
               %{plugin}
               %{plugin_instance}
               %{type}
               %{type_instance}
                   These placeholders are replaced by the identifier field of the same name.

               %{ds:name}
                   These placeholders are replaced by a (hopefully) human readable representation of the current
                   rate of this data source. If you changed the instance name (using the set or replace targets,
                   see below), it may not be possible to convert counter values to rates.

               Please note that these placeholders are case sensitive!

           Severity "FAILURE"|"WARNING"|"OKAY"
               Sets the severity of the message. If omitted, the severity "WARNING" is used.

           Example:

             <Target "notification">
               Message "Oops, the %{type_instance} temperature is currently %{ds:value}!"
               Severity "WARNING"
             </Target>

       replace
           Replaces parts of the identifier using regular expressions.

           Available options:

           Host Regex Replacement
           Plugin Regex Replacement
           PluginInstance Regex Replacement
           TypeInstance Regex Replacement
           MetaData String Regex Replacement
           DeleteMetaData String Regex
               Match the appropriate field with the given regular expression Regex. If the regular expression
               matches, that part that matches is replaced with Replacement. If multiple places of the input
               buffer match a given regular expression, only the first occurrence will be replaced.

               You can specify each option multiple times to use multiple regular expressions one after another.

           Example:

            <Target "replace">
              # Replace "example.net" with "example.com"
              Host "\\<example.net\\>" "example.com"

              # Strip "www." from hostnames
              Host "\\<www\\." ""
            </Target>

       set Sets part of the identifier of a value to a given string.

           Available options:

           Host String
           Plugin String
           PluginInstance String
           TypeInstance String
           MetaData String String
               Set the appropriate field to the given string. The strings for plugin instance, type instance,
               and meta data may be empty, the strings for host and plugin may not be empty. It's currently not
               possible to set the type of a value this way.

               The following placeholders will be replaced by an appropriate value:

               %{host}
               %{plugin}
               %{plugin_instance}
               %{type}
               %{type_instance}
                   These placeholders are replaced by the identifier field of the same name.

               %{meta:name}
                   These placeholders are replaced by the meta data value with the given name.

               Please note that these placeholders are case sensitive!

           DeleteMetaData String
               Delete the named meta data field.

           Example:

            <Target "set">
              PluginInstance "coretemp"
              TypeInstance "core3"
            </Target>

   Backwards compatibility
       If you use collectd with an old configuration, i. e. one without a Chain block, it will behave as it used
       to. This is equivalent to the following configuration:

        <Chain "PostCache">
          Target "write"
        </Chain>

       If you specify a PostCacheChain, the write target will not be added anywhere and you will have to make
       sure that it is called where appropriate. We suggest to add the above snippet as default target to your
       "PostCache" chain.

   Examples
       Ignore all values, where the hostname does not contain a dot, i. e. can't be an FQDN.

        <Chain "PreCache">
          <Rule "no_fqdn">
            <Match "regex">
              Host "^[^\.]*$"
            </Match>
            Target "stop"
          </Rule>
          Target "write"
        </Chain>

IGNORELISTS

       Ignorelists are a generic framework to either ignore some metrics or report specific metircs only.
       Plugins usually provide one or more options to specify the items (mounts points, devices, ...) and the
       boolean option "IgnoreSelected".

       Select String
           Selects the item String. This option often has a plugin specific name, e.g.  Sensor in the "sensors"
           plugin. It is also plugin specific what this string is compared to. For example, the "df" plugin's
           MountPoint compares it to a mount point and the "sensors" plugin's Sensor compares it to a sensor
           name.

           By default, this option is doing a case-sensitive full-string match. The following config will match
           "foo", but not "Foo":

             Select "foo"

           If String starts and ends with "/" (a slash), the string is compiled as a regular expression. For
           example, so match all item starting with "foo", use could use the following syntax:

             Select "/^foo/"

           The regular expression is not anchored, i.e. the following config will match "foobar", "barfoo" and
           "AfooZ":

             Select "/foo/"

           The Select option may be repeated to select multiple items.

       IgnoreSelected true|false
           If set to true, matching metrics are ignored and all other metrics are collected. If set to false,
           matching metrics are collected and all other metrics are ignored.

SEE ALSO

       collectd(1), collectd-exec(5), collectd-perl(5), collectd-unixsock(5), types.db(5), hddtemp(8),
       iptables(8), kstat(3KSTAT), mbmon(1), psql(1), regex(7), rrdtool(1), sensors(1)

AUTHOR

       Florian Forster <octo@collectd.org>