You cannot connect from several nodes to MQTT Broker with the same client id. On the other side this makes no sense since every NiFi node would get the same messages to handle (which is normally not a use case). To solve this problem you should set "run on primary node only" for the ConsumeMQTT processor. But unfortunately this seems not to work 😞 All nodes on the NiFi cluster still makes a connection. I think this is an issue in the development of the processor. It seems that ConsumeMQTT makes a connection to the MQTT broker on all nodes although it should run only on primary node. ... View more