Provided by: collectd-core_5.12.0-11_amd64 bug


       collectd-unixsock - Documentation of collectd's "unixsock plugin"


         # See collectd.conf(5)
         LoadPlugin unixsock
         # ...
         <Plugin unixsock>
           SocketFile "/path/to/socket"
           SocketGroup "collectd"
           SocketPerms "0770"
           DeleteSocket false


       The "unixsock plugin" opens an UNIX-socket over which one can interact with the daemon.
       This can be used to use the values collected by collectd in other applications, such as
       monitoring solutions, or submit externally collected values to collectd.

       For example, this plugin is used by collectd-nagios(1) to check if some value is in a
       certain range and exit with a Nagios-compatible exit code.


       Upon start the "unixsock plugin" opens a UNIX-socket and waits for connections. Once a
       connection is established the client can send commands to the daemon which it will answer,
       if it understand them.

       In general the plugin answers with a status line of the following form:

       Status Message

       If Status is greater than or equal to zero the message indicates success, if Status is
       less than zero the message indicates failure. Message is a human-readable string that
       further describes the return value.

       On success, Status furthermore indicates the number of subsequent lines of output (not
       including the status line). Each such lines usually contains a single return value. See
       the description of each command for details.

       The following commands are implemented:

       GETVAL Identifier
           If the value identified by Identifier (see below) is found the complete value-list is
           returned. The response is a list of name-value-pairs, each pair on its own line (the
           number of lines is indicated by the status line - see above). Each name-value-pair is
           of the form name=value.  Counter-values are converted to a rate, e. g. bytes per
           second.  Undefined values are returned as NaN.

             -> | GETVAL myhost/cpu-0/cpu-user
             <- | 1 Value found
             <- | value=1.260000e+00

           Returns a list of the values available in the value cache together with the time of
           the last update, so that querying applications can issue a GETVAL command for the
           values that have changed. Each return value consists of the update time as an epoch
           value and the identifier, separated by a space. The update time is the time of the
           last value, as provided by the collecting instance and may be very different from the
           time the server considers to be "now".

             -> | LISTVAL
             <- | 69 Values found
             <- | 1182204284 myhost/cpu-0/cpu-idle
             <- | 1182204284 myhost/cpu-0/cpu-nice
             <- | 1182204284 myhost/cpu-0/cpu-system
             <- | 1182204284 myhost/cpu-0/cpu-user

       PUTVAL Identifier [OptionList] Valuelist
           Submits one or more values (identified by Identifier, see below) to the daemon which
           will dispatch it to all its write-plugins.

           An Identifier is of the form "host/plugin-instance/type-instance" with both
           instance-parts being optional. If they're omitted the hyphen must be omitted, too.
           plugin and each instance-part may be chosen freely as long as the tuple (plugin,
           plugin instance, type instance) uniquely identifies the plugin within collectd. type
           identifies the type and number of values (i. e. data-set) passed to collectd. A large
           list of predefined data-sets is available in the types.db file.

           The OptionList is an optional list of Options, where each option is a key-value-pair.
           A list of currently understood options can be found below, all other options will be
           ignored. Values that contain spaces must be quoted with double quotes.

           Valuelist is a colon-separated list of the time and the values, each either an integer
           if the data-source is a counter, or a double if the data-source is of type "gauge".
           You can submit an undefined gauge-value by using U. When submitting U to a counter the
           behavior is undefined. The time is given as epoch (i. e. standard UNIX time).

           You can mix options and values, but the order is important: Options only effect
           following values, so specifying an option as last field is allowed, but useless. Also,
           an option applies to all following values, so you don't need to re-set an option over
           and over again.

           The currently defined Options are:

               Gives the interval in which the data identified by Identifier is being collected.

               Add meta data with the key key and the value value.

           Please note that this is the same format as used in the exec plugin, see

             -> | PUTVAL testhost/interface/if_octets-test0 interval=10 1179574444:123:456
             <- | 0 Success

       PUTNOTIF [OptionList] message=Message
           Submits a notification to the daemon which will then dispatch it to all plugins which
           have registered for receiving notifications.

           The PUTNOTIF command is followed by a list of options which further describe the
           notification. The message option is special in that it will consume the rest of the
           line as its value. The message, severity, and time options are mandatory.

           Valid options are:

           message=Message (REQUIRED)
               Sets the message of the notification. This is the message that will be made
               accessible to the user, so it should contain some useful information. As with all
               options: If the message includes spaces, it must be quoted with double quotes.
               This option is mandatory.

           severity=failure|warning|okay (REQUIRED)
               Sets the severity of the notification. This option is mandatory.

           time=Time (REQUIRED)
               Sets the time of the notification. The time is given as "epoch", i. e. as seconds
               since January 1st, 1970, 00:00:00. This option is mandatory.

               These "associative" options establish a relation between this notification and
               collected performance data. This connection is purely informal, i. e. the daemon
               itself doesn't do anything with this information. However, websites or GUIs may
               use this information to place notifications near the affected graph or table. All
               the options are optional, but plugin_instance without plugin or type_instance
               without type doesn't make much sense and should be avoided.

               Sets user defined meta information. The type key is a single character defining
               the type of the meta information.

               The current supported types are:

               s A string passed as-is.

           Please note that this is the same format as used in the exec plugin, see

             -> | PUTNOTIF type=temperature severity=warning time=1201094702 message=The roof is
           on fire!
             <- | 0 Success

       FLUSH [timeout=Timeout] [plugin=Plugin [...]] [identifier=Ident [...]]
           Flushes all cached data older than Timeout seconds. If no timeout has been specified,
           it defaults to -1 which causes all data to be flushed.

           If the plugin option has been specified, only the Plugin plugin will be flushed. You
           can have multiple plugin options to flush multiple plugins in one go. If the plugin
           option is not given all plugins providing a flush callback will be flushed.

           If the identifier option is given only the specified values will be flushed.  This is
           meant to be used by graphing or displaying frontends which want to have the latest
           values for a specific graph. Again, you can specify the identifier option multiple
           times to flush several values. If this option is not specified at all, all values will
           be flushed.

             -> | FLUSH plugin=rrdtool identifier=localhost/df/df-root
             <- | 0 Done: 2 successful, 0 errors

       Value or value-lists are identified in a uniform fashion:


       Where Plugin and Type are both either of type "Name" or "Name-Instance". If the identifier
       includes spaces, it must be quoted using double quotes. This sounds more complicated than
       it is, so here are some examples:

         "myups/snmp/temperature-Outlet 1"


       collectd ships the Perl-Module Collectd::Unixsock which provides an abstraction layer over
       the actual socket connection. It can be found in the directory bindings/perl/ in the
       source distribution or (usually) somewhere near /usr/share/perl5/ if you're using a
       package. If you want to use Perl to communicate with the daemon, you're encouraged to use
       and expand this module.


       collectd(1), collectd.conf(5), collectd-nagios(1), unix(7)


       Florian Forster <>