Provided by: collectd_4.3.0-1_i386 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"


       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, or submit
       externally collected values to collectd.

       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.

       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 space separated
           list of name-value-pairs:

           num name=value[ name=value[ ...]]

           If num is less then zero, an error occurred. Otherwise it contains
           the number of values that follow. Each value 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=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.

           The first line’s status number is the number of identifiers
           returned or less than zero if an error occurred. Each of the
           following lines contains the update time as an epoch value and the
           identifier, separated by a space.

             -> | LISTVAL
             <- | 69 Values found
             <- | 1182204284 leeloo/cpu-0/cpu-idle
             <- | 1182204284 leeloo/cpu-0/cpu-nice
             <- | 1182204284 leeloo/cpu-0/cpu-system
             <- | 1182204284 leeloo/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 it’s 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 if
           a key-value-pair. A list of currently understood options can be
           found below, all other options will be ignored.

           Valuelist is a colon-separated list of the time and the values,
           each either an integer if the data-source is a counter, of a double
           if the data-source if 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

           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.

           Please note that this is the same format as used in the exec
           plugin, see collectd-exec(5).

             -> | PUTVAL testhost/interface/if_octets-test0 interval=10
             <- | 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 if 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. This option must be the last option because
               the rest of the line will be its value, even if there are
               spaces and equal-signs following it! This option is mandatory.

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

           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.

               Please note that this is the same format as used in the exec
               plugin, see collectd-exec(5).

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


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


       Where Plugin and Type are both either of type "Name" or
       "Name-Instance". This sounds more complicated than it is, so here are
       some examples:


       Return values

       Unless otherwise noted the plugin answers with a line of the following

       Num Message

       If Num is zero the message indicates success, if Num is non-zero the
       message indicates failure. Message is a human-readable string that
       describes the return value further.

       Commands that return values may use Num to return the number of values
       that follow, such as the GETVAL command. These commands usually return
       a negative value on failure and never return zero.


       Shipped with the sourcecode comes the Perl-Module Collectd::Unixsock
       which provides an abstraction layer over the actual socket connection.
       It can be found in the directory contrib/PerlLib. 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 <>