global B<Interval> setting. If a plugin provides own support for specifying an
interval, that setting will take precedence.
+=item B<FlushInterval> I<Seconds>
+
+Specifies the the interval, in seconds, to call the flush callback if it's
+defined in this plugin. By default, this is disabled
+
+=item B<FlushTimeout> I<Seconds>
+
+Specifies the value of the timeout argument of the flush callback.
+
=back
=item B<AutoLoadPlugin> B<false>|B<true>
The I<AMQMP 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.
+possibly filtering out messages.
+
+B<Synopsis:>
<Plugin "amqp">
# Send values to an AMQP broker
=head2 Plugin C<curl_json>
The B<curl_json plugin> collects values from JSON data to be parsed by
-B<libyajl> (L<http://www.lloydforge.org/projects/yajl/>) retrieved via
+B<libyajl> (L<https://lloyd.github.io/yajl/>) retrieved via
either B<libcurl> (L<http://curl.haxx.se/>) or read directly from a
unix socket. The former can be used, for example, to collect values
from CouchDB documents (which are stored JSON notation), and the
=back
+=head2 Plugin C<mqtt>
+
+The I<MQTT plugin> can send metrics to MQTT (B<Publish> blocks) and receive
+values from MQTT (B<Subscribe> blocks).
+
+B<Synopsis:>
+
+ <Plugin mqtt>
+ <Publish "name">
+ Host "mqtt.example.com"
+ Prefix "collectd"
+ </Publish>
+ <Subscribe "name">
+ Host "mqtt.example.com"
+ Topic "collectd/#"
+ </Subscribe>
+ </Plugin>
+
+The plugin's configuration is in B<Publish> and/or B<Subscribe> blocks,
+configuring the sending and receiving direction respectively. The plugin will
+register a write callback named C<mqtt/I<name>> where I<name> is the string
+argument given to the B<Publish> block. Both types of blocks share many but not
+all of the following options. If an option is valid in only one of the blocks,
+it will be mentioned explicitly.
+
+B<Options:>
+
+=over 4
+
+=item B<Host> I<Hostname>
+
+Hostname of the MQTT broker to connect to.
+
+=item B<Port> I<Service>
+
+Port number or service name of the MQTT broker to connect to.
+
+=item B<User> I<UserName>
+
+Username used when authenticating to the MQTT broker.
+
+=item B<Password> I<Password>
+
+Password used when authenticating to the MQTT broker.
+
+=item B<ClientId> I<ClientId>
+
+MQTT client ID to use. Defaults to the hostname used by I<collectd>.
+
+=item B<QoS> [B<0>-B<2>]
+
+Sets the I<Quality of Service>, with the values C<0>, C<1> and C<2> meaning:
+
+=over 4
+
+=item B<0>
+
+At most once
+
+=item B<1>
+
+At least once
+
+=item B<2>
+
+Exactly once
+
+=back
+
+In B<Publish> blocks, this option determines the QoS flag set on outgoing
+messages and defaults to B<0>. In B<Subscribe> blocks, determines the maximum
+QoS setting the client is going to accept and defaults to B<2>. If the QoS flag
+on a message is larger than the maximum accepted QoS of a subscriber, the
+message's QoS will be downgraded.
+
+=item B<Prefix> I<Prefix> (Publish only)
+
+This plugin will use one topic per I<value list> which will looks like a path.
+I<Prefix> is used as the first path element and defaults to B<collectd>.
+
+An example topic name would be:
+
+ collectd/cpu-0/cpu-user
+
+=item B<Retain> B<false>|B<true> (Publish only)
+
+Controls whether the MQTT broker will retain (keep a copy of) the last message
+sent to each topic and deliver it to new subscribers. Defaults to B<false>.
+
+=item B<StoreRates> B<true>|B<false> (Publish only)
+
+Controls whether C<DERIVE> and C<COUNTER> metrics are converted to a I<rate>
+before sending. Defaults to B<true>.
+
+=item B<CleanSession> B<true>|B<false> (Subscribe only)
+
+Controls whether the MQTT "cleans" the session up after the subscriber
+disconnects or if it maintains the subscriber's subscriptions and all messages
+that arrive while the subscriber is disconnected. Defaults to B<true>.
+
+=item B<Topic> I<TopicName> (Subscribe only)
+
+Configures the topic(s) to subscribe to. You can use the single level C<+> and
+multi level C<#> wildcards. Defaults to B<collectd/#>, i.e. all topics beneath
+the B<collectd> branch.
+
+=back
+
=head2 Plugin C<mysql>
The C<mysql plugin> requires B<mysqlclient> to be installed. It connects to
Sets the URL to use to connect to the I<OpenLDAP> server. This option is
I<mandatory>.
+=item B<BindDN> I<BindDN>
+
+Name in the form of an LDAP distinguished name intended to be used for
+authentication. Defaults to empty string to establish an anonymous authorization.
+
+=item B<Password> I<Password>
+
+Password for simple bind authentication. If this option is not set,
+unauthenticated bind operation is used.
+
=item B<StartTLS> B<true|false>
Defines whether TLS must be used when connecting to the I<OpenLDAP> server.
Host "localhost"
Port "6379"
Timeout 1000
+ Prefix "collectd/"
+ Database 1
</Node>
</Plugin>
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
-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
+I<Sorted Sets> are kept in a I<Set> called C<collectd/values> (or
+C<${prefix}/values> if the B<Prefix> option was specified) and can be retrieved
+using the C<SMEMBERS> I<Redis> command. You can specify the database to use
+with the B<Database> parameter (default is C<0>). See
L<http://redis.io/commands#sorted_set> and L<http://redis.io/commands#set> for
details.
The B<Timeout> option sets the socket connection timeout, in milliseconds.
+=item B<Prefix> I<Prefix>
+
+Prefix used when constructing the name of the I<Sorted Sets> and the I<Set>
+containing all metrics. Defaults to C<collectd/>, so metrics will have names
+like C<collectd/cpu-0/cpu-user>. When setting this to something different, it
+is recommended but not required to include a trailing slash in I<Prefix>.
+
+=item B<Database> I<Index>
+
+This index selects the redis database to use for writing operations. Defaults to C<0>.
+
=back
=head2 Plugin C<write_riemann>