NAME

       collectd - System statistics collection daemon

SYNOPSIS

       collectd [options]

DESCRIPTION

       collectd is a daemon that receives system statistics and makes them available in a number of ways. The
       main daemon itself doesn't have any real functionality apart from loading, querying and submitting to
       plugins. For a description of available plugins please see "PLUGINS" below.

OPTIONS

       Most of collectd's configuration is done using using a configfile. See collectd.conf(5) for an in-depth
       description of all options.

       -C <config-file>
           Specify  an  alternative  config  file.  This  is  the place to go when you wish to change collectd's
           behavior. The path may be relative to the current working directory.

       -t  Test the configuration only. The program immediately exits after parsing the config  file.  A  return
           code not equal to zero indicates an error.

       -T  Test  the plugin read callbacks only. The program immediately exits after invoking the read callbacks
           once. A return code not equal to zero indicates an error.

       -P <pid-file>
           Specify an alternative pid file. This overwrites any settings in the config file. This is thought for
           init-scripts that require the PID-file in a certain directory to work correctly.  For  everyday-usage
           use the PIDFile config-option.

       -B  If  set, collectd will not try to create its base directory. If the base directory does not exist, it
           will exit rather than trying to create the directory.

       -f  Don't fork to the background. collectd will also not close standard file descriptors, detach from the
           session nor write a pid file. This is mainly thought for  'supervising'  init  replacements  such  as
           runit.  If  using  upstart  or systemd though, starting with version 5.5.0 collectd is able to notify
           these two init replacements, and does require forking to the background for process supervision.  The
           contrib/ directory has sample upstart and systemd configuration files.

       -h  Output usage information and exit.

PLUGINS

       As  noted  above,  the  real  power  of  collectd lies within its plugins. A (hopefully complete) list of
       plugins and short descriptions can be found in the README file that is distributed with  the  sourcecode.
       If you're using a package it's a good bet to search somewhere near /usr/share/doc/collectd.

       There are two big groups of plugins, input and output plugins:

       •   Input plugins are queried periodically. They somehow acquire the current value of whatever they where
           designed  to  work with and submit these values back to the daemon, i. e. they "dispatch" the values.
           As an example, the "cpu plugin" reads the current cpu-counters of time spent  in  the  various  modes
           (user, system, nice, ...) and dispatches these counters to the daemon.

       •   Output  plugins  get  the  dispatched  values  from  the  daemon and does something with them. Common
           applications are writing to RRD-files, CSV-files or sending the data over a network link to a  remote
           box.

       Of  course  not  all  plugins  fit neatly into one of the two above categories. The "network plugin", for
       example, is able to send (i. e. "write") and receive (i. e. "dispatch") values. Also, it opens  a  socket
       upon  initialization and dispatches the values when it receives them and isn't triggered at the same time
       the input plugins are being read. You can think of the network receive part as working asynchronous if it
       helps.

       In addition to the above, there are "logging plugins". Right now those are the "logfile plugin"  and  the
       "syslog  plugin".  With  these  plugins  collectd  can  provide  information about issues and significant
       situations to the user.  Several loglevels let you suppress uninteresting messages.

       Starting with version 4.3.0 collectd has support for monitoring. This  is  done  by  checking  thresholds
       defined  by  the  user.  If  a  value is out of range, a notification will be dispatched to "notification
       plugins". See collectd.conf(5) for more detailed information about threshold checking.

       Please note that some plugins, that provide other means of communicating with the daemon,  have  manpages
       of  their  own to describe their functionality in more detail. In particular those are collectd-email(5),
       collectd-exec(5), collectd-perl(5), collectd-snmp(5), and collectd-unixsock(5)

SIGNALS

       collectd accepts the following signals:

       SIGINT, SIGTERM
           These signals cause collectd to shut down all plugins and terminate.

       SIGUSR1
           This signal causes collectd to signal all plugins to flush  data  from  internal  caches.  E. g.  the
           "rrdtool  plugin"  will write all pending data to the RRD files. This is the same as using the "FLUSH
           -1" command of the "unixsock plugin".

SEE ALSO

       collectd.conf(5),    collectd-email(5),     collectd-exec(5),     collectd-perl(5),     collectd-snmp(5),
       collectd-unixsock(5), types.db(5), <http://collectd.org/>

AUTHOR

       Florian Forster <octo@collectd.org>

5.12.0.git                                         2024-03-31                                        COLLECTD(1)