When set to B<true>, various statistics about the I<collectd> daemon will be
collected, with "collectd" as the I<plugin name>. Defaults to B<false>.
-The "write_queue" I<plugin instance> reports the number of elements currently
-queued and the number of elements dropped off the queue by the
-B<WriteQueueLimitLow>/B<WriteQueueLimitHigh> mechanism.
+The following metrics are reported:
-The "cache" I<plugin instance> reports the number of elements in the value list
-cache (the cache you can interact with using L<collectd-unixsock(5)>).
+=over 4
+
+=item C<collectd-write_queue/queue_length>
+
+The number of metrics currently in the write queue. You can limit the queue
+length with the B<WriteQueueLimitLow> and B<WriteQueueLimitHigh> options.
+
+=item C<collectd-write_queue/derive-dropped>
+
+The number of metrics dropped due to a queue length limitation.
+If this value is non-zero, your system can't handle all incoming metrics and
+protects itself against overload by dropping metrics.
+
+=item C<collectd-cache/cache_size>
+
+The number of elements in the metric cache (the cache you can interact with
+using L<collectd-unixsock(5)>).
+
+=back
=item B<Include> I<Path> [I<pattern>]
=head2 Plugin C<amqp>
-The I<AMQMP plugin> can be used to communicate with other instances of
+The I<AMQP plugin> can be used to communicate with other instances of
I<collectd> or third party applications using an AMQP message broker. Values
are sent to or received from the broker, which handles routing, queueing and
possibly filtering or messages.
=head2 Plugin C<fhcount>
The C<fhcount> plugin provides statistics about used, unused and total number of
-file handles.
+file handles on Linux.
The I<fhcount plugin> provides the following configuration options:
means to concatenate the guest name and UUID (with a literal colon character
between, thus I<"foo:1234-1234-1234-1234">).
+At the moment of writing (collectd-5.5), hostname string is limited to 62
+characters. In case when combination of fields exceeds 62 characters,
+hostname will be truncated without a warning.
+
=item B<InterfaceFormat> B<name>|B<address>
When the virt plugin logs interface data, it sets the name of the collected
B<uuid> means use the guest's UUID.
+You can also specify combinations of these fields. For example B<name uuid>
+means to concatenate the guest name and UUID (with a literal colon character
+between, thus I<"foo:1234-1234-1234-1234">).
+
=back
=head2 Plugin C<vmem>
Values are submitted to I<Sorted Sets>, using the metric name as the key, and
the timestamp as the score. Retrieving a date range can then be done using the
-C<ZRANGEBYSCORE> I<Redis> command. Additionnally, all the identifiers of these
+C<ZRANGEBYSCORE> I<Redis> command. Additionally, all the identifiers of these
I<Sorted Sets> are kept in a I<Set> called C<collectd/values> and can be
retrieved using the C<SMEMBERS> I<Redis> command. See
L<http://redis.io/commands#sorted_set> and L<http://redis.io/commands#set> for
=item B<Node> I<Nodename>
The B<Node> block identifies a new I<Redis> node, that is a new I<Redis>
-instance running in an specified host and port. The name for node is a
+instance running on a specified host and port. The node name is a
canonical identifier which is used as I<plugin instance>. It is limited to
-64E<nbsp>characters in length.
+51E<nbsp>characters in length.
=item B<Host> I<Hostname>
=item B<AlwaysAppendDS> B<false>|B<true>
-If set the B<true>, append the name of the I<Data Source> (DS) to the
+If set to B<true>, append the name of the I<Data Source> (DS) to the
"service", i.e. the field that, together with the "host" field, uniquely
identifies a metric in I<Riemann>. If set to B<false> (the default), this is
only done when there is more than one DS.