Salesforce Exam MuleSoft Integration Architect I Topic 2 Question 28 Discussion

Correct answer is Depending on the Listener operation configuration, either all messages are consumed by ONLY the primary cluster node or else EACH message is consumed by ANY ONE cluster node

For applications running in clusters, you have to keep in mind the concept of primary node and how the connector will behave. When running in a cluster, the JMS listener default behavior will be to receive messages only in the primary node, no matter what kind of destination you are consuming from. In case of consuming messages from a Queue, you'll want to change this configuration to receive messages in all the nodes of the cluster, not just the primary.

This can be done with the primaryNodeOnly parameter:

<jms:listener config-ref='config' destination='${inputQueue}' primaryNodeOnly='false'/>