+=encoding UTF-8
+
=head1 NAME
collectd-exec - Documentation of collectd's C<exec plugin>
=head1 DESCRIPTION
-The C<exec plugin> forks of an executable either to receive values or to
+The C<exec plugin> forks off an executable either to receive values or to
dispatch notifications to the outside world. The syntax of the configuration is
explained in L<collectd.conf(5)> but summarized in the above synopsis.
See L<EXEC DATA FORMAT> below for a description of the output format expected
from these programs.
-B<Warning:> If the executable only writes one value and then exits I will be
+B<Warning:> If the executable only writes one value and then exits it will be
executed every I<Interval> seconds. If I<Interval> is short (the default is 10
seconds) this may result in serious system load.
Since examples usually let one understand a lot better, here are some:
- leeloo/cpu-0/cpu-idle N:2299366
- alice/interface/if_octets-eth0 interval=10 1180647081:421465:479194
-
-Since this action was the only one supported with older versions of the C<exec
-plugin> all lines were treated as if they were prefixed with B<PUTVAL>. This is
-still the case to maintain backwards compatibility but deprecated.
+ PUTVAL leeloo/cpu-0/cpu-idle N:2299366
+ PUTVAL alice/interface/if_octets-eth0 interval=10 1180647081:421465:479194
=item B<PUTNOTIF> [I<OptionList>] B<message=>I<Message>
HTTP: At first there is a "header" with one line per field. Every line consists
of a field name, ended by a colon, and the associated value until end-of-line.
The "header" is ended by two newlines immediately following another,
-i.E<nbsp>e. an empty line. The rest, basically the "body", is the message of
-the notification.
+i.e. an empty line. The rest, basically the "body", is the message of the
+notification.
The following is an example notification passed to a program:
Severity: FAILURE
- Time: 1200928930
+ Time: 1200928930.515
Host: myhost.mydomain.org
\n
This is a test notification to demonstrate the format
=item B<Time>
-The time in epoch, i.E<nbsp>e. as seconds since 1970-01-01 00:00:00 UTC.
+The time in epoch, i.e. as seconds since 1970-01-01 00:00:00 UTC. The value
+currently has millisecond precision (i.e. three decimal places), but scripts
+should accept arbitrary numbers of decimal places, including no decimal places.
=item B<Host>
The user, the binary is executed as, may not have root privileges, i.E<nbsp>e.
must have an UID that is non-zero. This is for your own good.
+=item
+
+Early versions of the plugin did not use a command but treated all lines as if
+they were arguments to the I<PUTVAL> command. When the I<PUTNOTIF> command was
+implemented, this behavior was kept for lines which start with an unknown
+command for backwards compatibility. This compatibility code has been removed
+in I<collectdE<nbsp>5>.
+
=back
=head1 SEE ALSO