bionic (5) gmond.conf.5.gz

Provided by: ganglia-monitor_3.6.0-7ubuntu2_amd64 bug

NAME

       gmond.conf - configuration file for ganglia monitoring daemon (gmond)

DESCRIPTION

       The gmond.conf file is used to configure the ganglia monitoring daemon (gmond) which is part of the
       Ganglia Distributed Monitoring System.

SECTIONS AND ATTRIBUTES

       All sections and attributes are case-insensitive.  For example, name or NAME or Name or NaMe are all
       equivalent.

       Some sections can be included in the configuration file multiple times and some sections are singular.
       For example, you can have only one cluster section to define the attributes of the cluster being
       monitored; however, you can have multiple udp_recv_channel sections to allow gmond to receive message on
       multiple UDP channels.

   cluster
       There should only be one cluster section defined.  This section controls how gmond reports the attributes
       of the cluster that it is part of.

       The cluster section has four attributes: name, owner, latlong and url.

       For example,

         cluster {
           name = "Millennium Cluster"
           owner = "UC Berkeley CS Dept."
           latlong = "N37.37 W122.23"
           url = "http://www.millennium.berkeley.edu/"
         }

       The name attributes specifies the name of the cluster of machines.  The owner tag specifies the
       administrators of the cluster.  The pair name/owner should be unique to all clusters in the world.

       The latlong attribute is the latitude and longitude GPS coordinates of this cluster on earth.  Specified
       to 1 mile accuracy with two decimal places per axis in decimal.

       The url for more information on the cluster.  Intended to give purpose, owner, administration, and
       account details for this cluster.

       There directives directly control the XML output of gmond.  For example, the cluster configuration
       example above would translate into the following XML.

         <CLUSTER NAME="Millennium Cluster" OWNER="UC Berkeley CS Dept."
                  LATLONG="N37.37 W122.23" URL="http://www.millennium.berkeley.edu/">
         ...
         </CLUSTER>

   host
       The host section provides information about the host running this instance of gmond. Currently only the
       location string attribute is supported. Example:

        host {
          location = "1,2,3"
        }

       The numbers represent Rack, Rank and Plane respectively.

   globals
       The globals section controls general characteristics of gmond such as whether is should daemonize, what
       user it should run as, whether is should send/receive date and such.  The globals section has the
       following attributes: daemonize, setuid, user, debug_level, mute, deaf, allow_extra_data, host_dmax,
       host_tmax, cleanup_threshold, gexec, send_metadata_interval and module_dir.

       For example,

         globals {
           daemonize = true
           setuid = true
           user = nobody
           host_dmax = 3600
           host_tmax = 40
         }

       The daemonize attribute is a boolean.  When true, gmond will daemonize.  When false, gmond will run in
       the foreground.

       The setuid attribute is a boolean.  When true, gmond will set its effective UID to the uid of the user
       specified by the user attribute.  When false, gmond will not change its effective user.

       The debug_level is an integer value.  When set to zero (0), gmond will run normally.  A debug_level
       greater than zero will result in gmond running in the foreground and outputting debugging information.
       The higher the debug_level the more verbose the output.

       The mute attribute is a boolean.  When true, gmond will not send data regardless of any other
       configuration directives.

       The deaf attribute is a boolean.  When true, gmond will not receive data regardless of any other
       configuration directives.

       The allow_extra_data attribute is a boolean.  When false, gmond will not send out the EXTRA_ELEMENT and
       EXTRA_DATA parts of the XML.  This might be useful if you are using your own frontend to the metric data
       and will like to save some bandwith.

       The host_dmax value is an integer with units in seconds.  When set to zero (0), gmond will never delete a
       host from its list even when a remote host has stopped reporting.  If host_dmax is set to a positive
       number then gmond will flush a host after it has not heard from it for host_dmax seconds.  By the way,
       dmax means "delete max".

       The host_tmax value is an integer with units in seconds. This value represents the maximum amount of time
       that gmond should wait between updates from a host. As messages may get lost in the network, gmond will
       consider the host as being down if it has not received any messages from it after 4 times this value. For
       example, if host_tmax is set to 20, the host will appear as down after 80 seconds with no messages from
       it. By the way, tmax means "timeout max".

       The cleanup_threshold is the minimum amount of time before gmond will cleanup any hosts or metrics where
       tn > dmax a.k.a. expired data.

       The gexec boolean allows you to specify whether gmond will announce the hosts availability to run gexec
       jobs.  Note: this requires that gexecd is running on the host and the proper keys have been installed.

       The send_metadata_interval establishes an interval in which gmond will send or resend the metadata
       packets that describe each enabled metric. This directive by default is set to 0 which means that gmond
       will only send the metadata packets at startup and upon request from other gmond nodes running remotely.
       If a new machine running gmond is added to a cluster, it needs to announce itself and inform all other
       nodes of the metrics that it currently supports. In multicast mode, this isn't a problem because any node
       can request the metadata of all other nodes in the cluster.  However in unicast mode, a resend interval
       must be established. The interval value is the minimum number of seconds between resends.

       The override_hostname and override_ip parameters allow an arbitrary hostname and/or IP (hostname can be
       optionally specified without IP) to use when identifying metrics coming from this host.

       The module_dir is an optional parameter indicating the directory where the DSO modules are to be located.
       If absent, the value to use is set at configure time with the --with-moduledir option which will default
       if omitted to the a subdirectory named "ganglia" in the directory where libganglia will be installed.

       For example, in a 32-bit Intel compatible Linux host that is usually:

         /usr/lib/ganglia

   udp_send_channel
       You can define as many udp_send_channel sections as you like within the limitations of memory and file
       descriptors.  If gmond is configured as mute this section will be ignored.

       The udp_send_channel has a total of seven attributes: mcast_join, mcast_if, host, port, ttl, bind and
       bind_hostname.  bind and bind_hostname are mutually exclusive.

       For example, the 2.5.x version gmond would send on the following single channel by default...

         udp_send_channel {
           mcast_join = 239.2.11.71
           port       = 8649
         }

       The mcast_join and mcast_if attributes are optional.  When specified gmond will create the UDP socket and
       join the mcast_join multicast group and send data out the interface specified by mcast_if.

       You can use the bind attribute to bind to a particular local address to be used as the source for the
       multicast packets sent or let gmond resolve the default hostname if bind_hostname = yes.

       If only a host and port are specified then gmond will send unicast UDP messages to the hosts specified.

       You could specify multiple unicast hosts for redundancy as gmond will send UDP messages to all UDP
       channels.

       Be careful though not to mix multicast and unicast attributes in the same udp_send_channel definition.

       For example...

         udp_send_channel {
           host = host.foo.com
           port = 2389
         }
         udp_send_channel {
           host = 192.168.3.4
           port = 2344
         }

       would configure gmond to send messages to two hosts.  The host specification can be an IPv4/IPv6 address
       or a resolvable hostname.

       The ttl attribute lets you modify the Time-To-Live (TTL) of outgoing messages (unicast or multicast).

   udp_recv_channel
       You can specify as many udp_recv_channel sections as you like within the limits of memory and file
       descriptors.  If gmond is configured deaf this attribute will be ignored.

       The udp_recv_channel section has following attributes: mcast_join, bind, port, mcast_if, family,
       retry_bind and buffer.  The udp_recv_channel can also have an acl definition (see ACCESS CONTROL LISTS
       below).

       For example, the 2.5.x gmond ran with a single udp receive channel...

         udp_recv_channel {
           mcast_join = 239.2.11.71
           bind       = 239.2.11.71
           port       = 8649
         }

       The mcast_join and mcast_if should only be used if you want to have this UDP channel receive multicast
       packets the multicast group mcast_join on interface mcast_if.  If you do not specify multicast attributes
       then gmond will simply create a UDP server on the specified port.

       You can use the bind attribute to bind to a particular local address.

       The family address is set to inet4 by default.  If you want to bind the port to an inet6 port, you need
       to specify that in the family attribute.  Ganglia will not allow IPV6=>IPV4 mapping (for portability and
       security reasons).  If you want to listen on both inet4 and inet6 for a particular port, explicitly state
       it with the following:

         udp_recv_channel {
           port = 8666
           family = inet4
         }
         udp_recv_channel {
           port = 8666
           family = inet6
         }

       If you specify a bind address, the family of that address takes precedence.  f your IPv6 stack doesn't
       support IPV6_V6ONLY, a warning will be issued but gmond will continue working (this should rarely
       happen).

       Multicast Note: for multicast, specifying a bind address with the same value used for mcast_join will
       prevent unicast UDP messages to the same port from being processed.

       The sFlow protocol (see http://www.sflow.org) can be used to collect a standard set of performance
       metrics from servers. For servers that don't include embedded sFlow agents, an open source sFlow agent is
       available on SourceForge (see http://host-sflow.sourceforge.net).

       To configure gmond to receive sFlow datagrams, simply add a udp_recv_channel with the port set to 6343
       (the IANA registered port for sFlow):

         udp_recv_channel {
           port = 6343
         }

       Note: sFlow is unicast protocol, so don't include mcast_join join.  Note: To use some other port for
       sFlow, set it here and then specify the port in an sflow section (see below).

       gmond will fail to run if it can't bind to all defined udp_recv_channels.  Sometimes, on machines
       configured by DHCP, for example, the gmond daemon starts before a network address is assigned to the
       interface.  Consequently, the bind fails and the gmond daemon does not run.  To assist in this situation,
       the boolean parameter retry_bind can be set to the value true and then the daemon will not abort on
       failure, it will enter a loop and repeat the bind attempt every 60 seconds:

         udp_recv_channel {
           port = 6343
           retry_bind = true
         }

       If you have a large system with lots of metrics, you might experience UDP drops. This happens when gmond
       is not able to process the UDP fast enough from the network. In this case you might consider changing
       your setup into a more distributed setup using aggregator gmond hosts.  Alternatively you can choose to
       create a bigger receive buffer:

         udp_recv_channel {
           port = 6343
           buffer = 10485760
         }
       B<buffer> is specified in bytes, i.e.: 10485760 will allow 10MB UDP
       to be buffered in memory.

       Note: increasing buffer size will increase memory usage by gmond

   tcp_accept_channel
       You can specify as many tcp_accept_channel sections as you like within the limitations of memory and file
       descriptors.  If gmond is configured to be mute, then these sections are ignored.

       The tcp_accept_channel has the following attributes: bind, port, interface, family and timeout.  A
       tcp_accept_channel may also have an acl section specified (see ACCESS CONTROL LISTS below).

       For example, 2.5.x gmond would accept connections on a single TCP channel.

         tcp_accept_channel {
           port = 8649
         }

       The bind address is optional and allows you to specify which local address gmond will bind to for this
       channel.

       The port is an integer than specifies which port to answer requests for data.

       The family address is set to inet4 by default.  If you want to bind the port to an inet6 port, you need
       to specify that in the family attribute.  Ganglia will not allow IPV6=>IPV4 mapping (for portability and
       security reasons).  If you want to listen on both inet4 and inet6 for a particular port, explicitly state
       it with the following:

         tcp_accept_channel {
           port = 8666
           family = inet4
         }
         tcp_accept_channel {
           port = 8666
           family = inet6
         }

       If you specify a bind address, the family of that address takes precedence.  If your IPv6 stack doesn't
       support IPV6_V6ONLY, a warning will be issued but gmond will continue working (this should rarely
       happen).

       The timeout attribute allows you to specify how many microseconds to block before closing a connection to
       a client.  The default is set to -1 (blocking IO) and will never abort a connection regardless of how
       slow the client is in fetching the report data.

       The interface is not implemented at this time (use bind).

   collection_group
       You can specify as many collection_group section as you like within the limitations of memory.  A
       collection_group has the following attributes: collect_once, collect_every and time_threshold.  A
       collection_group must also contain one or more metric sections.

       The metric section has the following attributes: (one of name or name_match; name_match is only permitted
       if pcre support is compiled in), value_threshold and title.  For a list of available metric names, run
       the following command:

         % gmond -m

       Here is an example of a collection group for a static metric...

         collection_group {
           collect_once   = yes
           time_threshold = 1800
           metric {
            name = "cpu_num"
            title = "Number of CPUs"
           }
         }

       This collection_group entry would cause gmond to collect the cpu_num metric once at startup (since the
       number of CPUs will not change between reboots).  The metric cpu_num would be send every 1/2 hour (1800
       seconds).  The default value for the time_threshold is 3600 seconds if no time_threshold is specified.

       The time_threshold is the maximum amount of time that can pass before gmond sends all metrics specified
       in the collection_group to all configured udp_send_channels.  A metric may be sent before this
       time_threshold is met if during collection the value surpasses the value_threshold (explained below).

       Here is an example of a collection group for a volatile metric...

         collection_group {
           collect_every = 60
           time_threshold = 300
           metric {
             name = "cpu_user"
             value_threshold = 5.0
             title = "CPU User"
           }
           metric {
             name = "cpu_idle"
             value_threshold = 10.0
             title = "CPU Idle"
           }
         }

       This collection group would collect the cpu_user and cpu_idle metrics every 60 seconds (specified in
       collect_every).  If cpu_user varies by 5.0% or cpu_idle varies by 10.0%, then the entire collection_group
       is sent.  If no value_threshold is triggered within time_threshold seconds (in this case 300), the entire
       collection_group is sent.

       Each time the metric value is collected the new value is compared with the old value collected.  If the
       difference between the last value and the current value is greater than the value_threshold, the entire
       collection group is send to the udp_send_channels defined.

       It's important to note that all metrics in a collection group are sent even when only a single
       value_threshold is surpassed.

       In addition a user friendly title can be substituted for the metric name by including a title within the
       metric section.

       By using the name_match parameter instead of name, it is possible to use a single definition to configure
       multiple metrics that match a regular expression.  The perl compatible regular expression (pcre) syntax
       is used.  This approach is particularly useful for a series of metrics that may vary in number between
       reboots (e.g. metric names that are generated for each individual NIC or CPU core).

       Here is an example of using the name_match directive to enable the multicpu metrics:

         metric {
           name_match = "multicpu_([a-z]+)([0-9]+)"
           value_threshold = 1.0
           title = "CPU-\\2 \\1"
         }

       Note that in the example above, there are two matches: the alphabetical match matches the variations of
       the metric name (e.g. idle, system) while the numeric match matches the CPU core number.  The second
       thing to note is the use of substitutions within the argument to title.

       If both name and name_match are specified, then name is ignored.

   Modules
       A modules section contains the parameters that are necessary to load a metric module. A metric module is
       a dynamically loadable module that extends the available metrics that gmond is able to collect. Each
       modules section contains at least one module section.  Within a module section are the directives name,
       language, enabled, path and params.  The module name is the name of the module as determined by the
       module structure if the module was developed in C/C++.  Alternatively, the name can be the name of the
       source file if the module has been implemented in a interpreted language such as python.  A language
       designation must be specified as a string value for each module.  The language directive must correspond
       to the source code language in which the module was implemented (ex. language = "python").  If a language
       directive does not exist for the module, the assumed language will be "C/C++". The enabled directive
       allows a metric module to be easily enabled or disabled through the configuration file. If the enabled
       directive is not included in the module configuration, the enabled state will default to "yes". One thing
       to note is that if a module has been disabled yet the metric which that module implements is still listed
       as part of a collection group, gmond will produce a warning message.  However gmond will continue to
       function normally by simply ignoring the metric. The path is the path from which gmond is expected to
       load the  module (C/C++ compiled dynamically loadable module only).  The params directive can be used to
       pass a single string parameter directly to the module initialization function (C/C++ module only).
       Multiple parameters can be passed to the module's initialization function by including one or more param
       sections. Each param section must be named and contain a value directive. Once a module has been loaded,
       the additional metrics can be discovered by invoking gmond -m.

          modules {
            module {
              name = "example_module"
              language = "C/C++"
              enabled = yes
              path = "modexample.so"
              params = "An extra raw parameter"
              param RandomMax {
                value = 75
              }
              param ConstantValue {
                value = 25
              }
            }
          }

   sFlow
       The sflow group is optional and has the following optional attributes: udp_port, accept_vm_metrics,
       accept_http_metrics, accept_memcache_metrics, accept_jvm_metrics,
       multiple_http_instances,multiple_memcache_instances, multiple_jvm_instances. By default, a
       udp_recv_channel on port 6343 (the IANA registered port for sFlow) is all that is required to accept and
       process sFlow datagrams.  To receive sFlow on some other port requires both a udp_recv_channel for the
       other port and a udp_port setting here. For example:

          udp_recv_channel {
            port = 7343
          }

          sflow {
            udp_port = 7343
          }

       An sFlow agent running on a hypervisor may also be sending metrics for its local virtual machines.  By
       default these metrics are ignored, but the accept_vm_metrics flag can be used to accept those metrics
       too,  and prefix them with an identifier for each virtual machine.

          sflow {
            accept_vm_metrics = yes
          }

       The sFlow feed may also contain metrics sent from HTTP or memcached servers,  or from Java VMs.  Extra
       options can be used to ignore or accept these metrics,  and to indicate that there may be multiple
       instances per host.  For example:

           sflow {
             accept_http_metrics = yes
             multiple_http_instances = yes
           }

       will allow the HTTP metrics, and also mark them with a distinguishing identifier so that each instance
       can be trended separately.  (If multiple instances are reporting and this flag is not set,  the results
       are likely to be garbled.)

   Include
       This directive allows the user to include additional configuration files rather than having to add all
       gmond configuration directives to the gmond.conf file.  The following example includes any file with the
       extension of .conf contained in the directory conf.d as if the contents of the included configuration
       files were part of the original gmond.conf file. This allows the user to modularize their configuration
       file.  One usage example might be to load individual metric modules by including module specific .conf
       files.

       include ('/etc/ganglia/conf.d/*.conf')

ACCESS CONTROL

       The udp_recv_channel and tcp_accept_channel directives can contain an Access Control List (ACL).  This
       ACL allows you to specify exactly which hosts gmond process data from.

       An example of an acl entry looks like

         acl {
           default = "deny"
           access {
             ip = 192.168.0.4
             mask = 32
             action = "allow"
           }
         }

       This ACL will by default reject all traffic that is not specifically from host 192.168.0.4 (the mask size
       for an IPv4 address is 32, the mask size for an IPv6 address is 128 to represent a single host).

       Here is another example

         acl {
           default = "allow"
           access {
             ip = 192.168.0.0
             mask = 24
             action = "deny"
           }
           access {
             ip = ::ff:1.2.3.0
             mask = 120
             action = "deny"
           }
         }

       This ACL will by default allow all traffic unless it comes from the two subnets specified with action =
       "deny".

EXAMPLE

       The default behavior for a 2.5.x gmond would be specified as...

         udp_recv_channel {
           mcast_join = 239.2.11.71
           bind       = 239.2.11.71
           port       = 8649
         }
         udp_send_channel {
           mcast_join = 239.2.11.71
           port       = 8649
         }
         tcp_accept_channel {
           port       = 8649
         }

       To see the complete default configuration for gmond simply run:

         % gmond -t

       gmond will print out its default behavior in a configuration file and then exit.  Capturing this output
       to a file can serve as a useful starting point for creating your own custom configuration.

         % gmond -t > custom.conf

       edit custom.conf to taste and then

         % gmond -c ./custom.conf

SEE ALSO

       gmond(1).

NOTES

       The ganglia web site is at http://ganglia.info/.

       Copyright (c) 2005 The University of California, Berkeley