Spring JMS acknowledgement behavior with TIBCO EMS EXPLICIT_CLIENT_DUPS_OK_ACKNOWLEDGE

Question

I am using Spring JMS with TIBCO EMS queue/topic for my spring boot application. The TIBCO EMS queue is setup with EXPLICIT_CLIENT_DUPS_OK_ACKNOWLEDGE. In my code, I am not setting the acknowledgment mode, so I assume spring will take it s default AUTO_ACKNOWLEDGE. The behavior I notice in my listener onMessage method is, if the application successfully process the message, no redelivery of the same message And if the application throws a RuntimeException, there is a redelivery of the same message. The code is also with setSessionTransacted to true with DefaultJmsListenerContainerFactory. In this scenario, is the spring actually acknowledging the message on my behalf or do the code need to set the message.acknowledge().

Answer 1

See the javadocs for Session. Auto means the provider library automatically acks the message when consumer.receive() returns it, or the consumer.messsageListener() exits.

With a SimpleMessageListenerContainer, your listener is called directly by the provider's Consumer so messages won't be auto-ack'd until your listener exits normally.

The DirectMessageListenerContainer calls receive() instead and calls your listener on its own thread. Hence we need transactions to roll back the ack after an exception is thrown.