1COLLECTD(1) collectd COLLECTD(1)
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6 collectd - System statistics collection daemon
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9 collectd [options]
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12 collectd is a daemon that receives system statistics and makes them
13 available in a number of ways. The main daemon itself doesn't have any
14 real functionality apart from loading, querying and submitting to
15 plugins. For a description of available plugins please see "PLUGINS"
16 below.
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19 Most of collectd's configuration is done using using a configfile. See
20 collectd.conf(5) for an in-depth description of all options.
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22 -C <config-file>
23 Specify an alternative config file. This is the place to go when
24 you wish to change collectd's behavior. The path may be relative to
25 the current working directory.
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27 -t Test the configuration only. The program immediately exits after
28 parsing the config file. A return code not equal to zero indicates
29 an error.
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31 -T Test the plugin read callbacks only. The program immediately exits
32 after invoking the read callbacks once. A return code not equal to
33 zero indicates an error.
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35 -P <pid-file>
36 Specify an alternative pid file. This overwrites any settings in
37 the config file. This is thought for init-scripts that require the
38 PID-file in a certain directory to work correctly. For everyday-
39 usage use the PIDFile config-option.
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41 -B If set, collectd will not try to create its base directory. If the
42 base directory does not exist, it will exit rather than trying to
43 create the directory.
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45 -f Don't fork to the background. collectd will also not close standard
46 file descriptors, detach from the session nor write a pid file.
47 This is mainly thought for 'supervising' init replacements such as
48 runit. If using upstart or systemd though, starting with version
49 5.5.0 collectd is able to notify these two init replacements, and
50 does require forking to the background for process supervision. The
51 contrib/ directory has sample upstart and systemd configuration
52 files.
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54 -h Output usage information and exit.
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57 As noted above, the real power of collectd lies within it's plugins. A
58 (hopefully complete) list of plugins and short descriptions can be
59 found in the README file that is distributed with the sourcecode. If
60 you're using a package it's a good bet to search somewhere near
61 /usr/share/doc/collectd.
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63 There are two big groups of plugins, input and output plugins:
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65 · Input plugins are queried periodically. They somehow acquire the
66 current value of whatever they where designed to work with and
67 submit these values back to the daemon, i. e. they "dispatch" the
68 values. As an example, the "cpu plugin" reads the current cpu-
69 counters of time spent in the various modes (user, system, nice,
70 ...) and dispatches these counters to the daemon.
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72 · Output plugins get the dispatched values from the daemon and does
73 something with them. Common applications are writing to RRD-files,
74 CSV-files or sending the data over a network link to a remote box.
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76 Of course not all plugins fit neatly into one of the two above
77 categories. The "network plugin", for example, is able to send (i. e.
78 "write") and receive (i. e. "dispatch") values. Also, it opens a socket
79 upon initialization and dispatches the values when it receives them and
80 isn't triggered at the same time the input plugins are being read. You
81 can think of the network receive part as working asynchronous if it
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84 In addition to the above, there are "logging plugins". Right now those
85 are the "logfile plugin" and the "syslog plugin". With these plugins
86 collectd can provide information about issues and significant
87 situations to the user. Several loglevels let you suppress
88 uninteresting messages.
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90 Starting with version 4.3.0 collectd has support for monitoring. This
91 is done by checking thresholds defined by the user. If a value is out
92 of range, a notification will be dispatched to "notification plugins".
93 See collectd.conf(5) for more detailed information about threshold
94 checking.
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96 Please note that some plugins, that provide other means of
97 communicating with the daemon, have manpages of their own to describe
98 their functionality in more detail. In particular those are
99 collectd-email(5), collectd-exec(5), collectd-perl(5),
100 collectd-snmp(5), and collectd-unixsock(5)
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103 collectd accepts the following signals:
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105 SIGINT, SIGTERM
106 These signals cause collectd to shut down all plugins and
107 terminate.
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109 SIGUSR1
110 This signal causes collectd to signal all plugins to flush data
111 from internal caches. E. g. the "rrdtool plugin" will write all
112 pending data to the RRD files. This is the same as using the "FLUSH
113 -1" command of the "unixsock plugin".
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116 collectd.conf(5), collectd-email(5), collectd-exec(5),
117 collectd-perl(5), collectd-snmp(5), collectd-unixsock(5), types.db(5),
118 <http://collectd.org/>
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121 Florian Forster <octo@collectd.org>
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1255.8.0.145.gca1cb27 2018-10-23 COLLECTD(1)