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MQTT Inbound Endpoint¶

Introduction¶

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.

Syntax¶

<inboundEndpoint xmlns="http://ws.apache.org/ns/synapse" name="Test" sequence="TestIn" onError="fault" protocol="mqtt" suspend="false">
   <parameters>
      <parameter name="sequential">true</parameter>
      <parameter name="mqtt.connection.factory">mqttFactory</parameter>
      <parameter name="mqtt.server.host.name">localhost</parameter>
      <parameter name="mqtt.server.port">1883</parameter>
      <parameter name="mqtt.topic.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="mqtt.temporary.store.directory">m1y</parameter>
      <parameter name="mqtt.reconnection.interval">5</parameter>
   </parameters>
</inboundEndpoint>

Properties¶

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.
mqtt.server.host.name	Address of the message broker (eg., localhost).
mqtt.server.port	Port of the message broker (e.g., 1883).
mqtt.topic.name	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.
mqtt.client.id	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.
mqtt.temporary.store.directory	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.

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