ekuiper-new/docs/rules/sources/mqtt.md

MQTT source

XStream provides built-in support for MQTT source stream, which can subscribe the message from MQTT broker and feed into the XStream processing pipeline. The configuration file of MQTT source is at $xstream/etc/mqtt_source.yaml. Below is the file format.

#Global MQTT configurations
default:
  qos: 1
  sharedsubscription: true
  servers: [tcp://127.0.0.1:1883]
  #TODO: Other global configurations


#Override the global configurations
demo: #Conf_key
  qos: 0
  servers: [tcp://10.211.55.6:1883]

Global MQTT configurations

Use can specify the global MQTT settings here. The configuration items specified in default section will be taken as default settings for all MQTT connections.

qos

The default subscription QoS level.

sharedsubscription

Whether use the shared subscription mode or not. If using the shared subscription mode, then if there are multiple XStream process can be load balanced.

servers

The server list for MQTT message broker. Currently, only ONE server can be specified.

Override the default settings

If you have a specific connection that need to overwrite the default settings, you can create a customized section. In the previous sample, we create a specific setting named with demo. Then you can specify the configuration with option CONF_KEY when creating the stream definition (see stream specs for more info).

Sample

demo (
		...
	) WITH (datasource="test/", FORMAT="JSON", KEY="USERID", CONF_KEY="demo");

The configuration keys used for these specific settings are the same as in default settings, any values specified in specific settings will overwrite the values in default section.