MQTT Inbound Endpoint


MQ Telemetry Transport (MQTT) is a lightweight broker-based publish/subscribe messaging protocol, designed to be open, simple, lightweight and easy to implement. These characteristics make it ideal for use in constrained environments:

  • Where the network is expensive, has low bandwidth, or is unreliable.
  • When running on an embedded device with limited processor or memory resources.


<inboundEndpoint xmlns="" name="Test" sequence="TestIn" onError="fault" protocol="mqtt" suspend="false">
      <parameter name="sequential">true</parameter>
      <parameter name="mqtt.connection.factory">mqttFactory</parameter>
      <parameter name="">localhost</parameter>
      <parameter name="mqtt.server.port">1883</parameter>
      <parameter name="">ei.test2</parameter>
      <parameter name="mqtt.subscription.qos">2</parameter>
      <parameter name="content.type">application/xml</parameter>
      <parameter name="mqtt.session.clean">false</parameter>
      <parameter name="mqtt.ssl.enable">false</parameter>
      <parameter name="mqtt.subscription.username">client</parameter>
      <parameter name="mqtt.subscription.password">e13</parameter>
      <parameter name="">m1y</parameter>
      <parameter name="mqtt.reconnection.interval">5</parameter>


Listed below are the properties used for creating an MQTT inbound endpoint.

Required Properties

The following properties are required when creating a MQTT inbound endpoint.

Property Description
mqtt.connection.factory Name of the connection factory. Address of the message broker (eg., localhost).
mqtt.server.port Port of the message broker (e.g., 1883). MQTT topic to which the message should be published.
content.type The content type of the message, i.e., XML or JSON)
coordination This parameter is only applicable in a clustered environment.
In a cluster environment an inbound endpoint will only be executed in worker nodes. If this parameter is set to true in a clustered environment, the inbound will only be executed in a single worker node. Once the running worker node is down, the inbound will start on another available worker node in the cluster. By default, this setting is true.
sequential The behaviour when executing the given sequence.
sequential The behavior when executing the given sequence.
When set as true , mediation will happen within the same thread. When set as false , the mediation engine will use the inbound thread pool. The default thread pool values can be found in the MI_HOME/conf/deployment.toml file, under the `[mediation]` section. The default setting is true.
Suspend If the inbound listener should pause when accepting incoming requests, set this to true. If the inbound listener should not pause when accepting incoming requests, set this to false.

Optional Properties

The following optional properties can be configured when creating an MQTT inbound endpoint.

Property Description
mqtt.subscription.qos The quality of service level that need to be maintained with the subscription. The quality of service level can be either 0,1 or 2.
0 - Specifying this level ensures that the message delivery is efficient. However, specifying this level does not guarantee that the message will be delivered to its recipient.
1 - Specifying this level ensures that the message is delivered at least once, but this can lead to messages being duplicated.
2 - This is the highest level of quality of service. Specifying this guarantees that the message is delivered and that it is delivered only once. The id of the client.
mqtt.session.clean Whether the client and server should remember the state across restarts and reconnects.
mqtt.ssl.enable Whether to use TCP connection or SSL connection.
mqtt.subscription.username The username for the subscription.
mqtt.subscription.password The password for the subscription. Path of the directory to be used as the persistent data store for quality of service purposes.
mqtt.reconnection.interval The retry interval to reconnect to the MQTT server.