$SYS - System Topic

The $SYS topic path begins with $SYS/brokers/{node}/. is the name of the node where the event/message is generated, for example:

$SYS system message publish interval is configured in etc/emqx.conf:

TIP

Most of the data of the $SYS topic in EMQX Broker can be obtained through other method with lower Couplings. The device online and offline status can be obtained through Webhook), and the node and cluster status can be obtained through .

$SYS topic prefix:

The Payload of the ‘connected’ event message can be parsed into JSON format:

System topic prefix : $SYS/brokers/${node}/stats/

Subscription statistics

Routes statistics

The topics.count and topics.max are numerically equal to routes.count and routes.max.

System Topic Prefix : $SYS/brokers/${node}/metrics/

sent and received bytes statistics

MQTT sent and received messages statistics

System Topic Prefix: $SYS/brokers/${node}/sysmon/