title: MQTT: Broker miscellaneous information
agents: mqtt
catalog: app/mqtt
license: GPLv2
distribution: check_mk
description:
 This check measures miscellaneous information of a MQTT broker instance. It
 displays the total number of subscriptions active on the broker and the socket
 connection rate.

 To make this check work you have to configure the special agent {agent_mqtt}
 which connects via MQTT to the broker to gather information from the {$SYS/}
 topic.

 This check has been developed with Mosquitto message broker but might also work
 with other brokers. The available values vary from broker to broker and from
 version to version.

 Please note that this check may only be useful if you connect it directly to a
 broker. In case you want to monitor a multi-tentant cluster, this check is
 only useful if configure it for each node since the {$SYS/} topic is is node
 specific. It is not useful to use this check through a load balancer.

 The check is always {OK}.

item:
 The instance ID configured in the special agent.

discovery:
 One service is created for each instance.
