Advanced

EMQ 2.0-rc.2 release supports Local Subscription and Shared Subscription.

Local Subscription

The EMQ broker will not create global routes for Local Subscription, and only dispatch MQTT messages on local node.

mosquitto_sub -t '$local/topic'

mosquitto_pub -t 'topic'

Usage: subscribe a topic with $local/ prefix.

Shared Subscription

Shared Subscription supports Load balancing to distribute MQTT messages between multiple subscribers in the same group:

                            ---------
                            |       | --Msg1--> Subscriber1
Publisher--Msg1,Msg2,Msg3-->|  EMQ  | --Msg2--> Subscriber2
                            |       | --Msg3--> Subscriber3
                            ---------

Two ways to create a shared subscription:

Prefix Examples
$queue/ mosquitto_sub -t ‘$queue/topic
$share/<group>/ mosquitto_sub -t ‘$share/group/topic