MQTT Source Connector for Confluent Platform

The Kafka Connect MQTT Source connector connects to a MQTT broker and subscribes to the specified topics. SSL is supported. For information on how to create SSL keys and certificates, see Creating SSL Keys and Certificates. For the relevant configuration properties, see the MQTT Source connector configuration reference.


At least once delivery

This connector guarantees that records are delivered to the Kafka topic at least once. If the connector restarts, there may be some duplicate records in the Kafka topic.

Multiple tasks

The MQTT Source connector supports running one or more tasks. You can specify the number of tasks in the tasks.max configuration parameter. This can lead to huge performance gains when multiple files need to be parsed.

Configuration Properties

For a complete list of configuration properties for this source connector, see MQTT Source Connector Configuration Properties.


For an example of how to get Kafka Connect connected to Confluent Cloud, see Distributed Cluster.

Usage Notes

If you need to change the topic take a look at the RegexRouter transformation which can be used to change the topic name before it is written to Apache Kafka®.

The output of this connector is an envelope with all of the properties of the incoming message. The body of the message is written to the value as bytes. The key is the topic the message was written to.


Property-based example

This configuration is used typically along with standalone workers.

 mqtt.server.uri=< Required Configuration >
 mqtt.topics=< Required Configuration >

REST-based example

This configuration is used typically along with distributed workers. Write the following json to connector.json, configure all of the required values, and use the command below to post the configuration to one the distributed connect worker(s). Check here for more information about the Kafka Connect REST API

Connect Distributed REST example:

   "config" : {
     "name" : "MqttSourceConnector1",
     "connector.class" : "io.confluent.connect.mqtt.MqttSourceConnector",
     "tasks.max" : "1",
     "mqtt.server.uri" : "< Required Configuration >",
     "mqtt.topics" : "< Required Configuration >"

Use curl to post the configuration to one of the Kafka Connect Workers. Change http://localhost:8083/ the endpoint of one of your Kafka Connect worker(s).

  • Create a new connector:

    curl -s -X POST -H 'Content-Type: application/json' --data @connector.json http://localhost:8083/connectors
  • Update an existing connector:

    curl -s -X PUT -H 'Content-Type: application/json' --data @connector.json http://localhost:8083/connectors/MqttSourceConnector1/config