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.

       -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 it's  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>

5.7.2.git                                          2020-03-04                                        COLLECTD(1)