Message End-of-Life

9. The broker processes the client acknowledgement, and deletes the (persistent) message when all acknowledgements have been received.

10. The broker confirms to the consumer’s client runtime that the client acknowledgement has been processed.

The broker can discard a message before it is consumed if the administrator deletes the message from a destination or if the administrator removes or redefines a durable subscription, thereby causing a message in a topic destination to be removed without it being delivered. In other situations, you might want the broker to store the messages in a special destination called the dead message queue rather than discard them. A message is placed on the dead message queue when it expires, when it is removed due to memory limits, or when delivery fails due to the client’s throwing an exception. Storing messages in the dead message queue allows you to troubleshoot the system and recover messages in certain situations.