5.2.2. Durable Queues

By default, the lifetime of a queue is bound to the execution of the server process. When the server shuts down the queues are destroyed, and need to be re-created when the broker is restarted. A durable queue is a queue that is automatically re-established after a broker is restarted due to a planned or unplanned shutdown.

When the server shuts down and the queues are destroyed, any messages in those queues are lost. As well as automatic re-creation on server restart, durable queues provide message persistence for messages that request it. Messages that are marked as persistent and sent to a durable queue are stored and re-delivered when the durable queue is re-established after a shutdown.

Note that not all messages sent to a durable queue are persistent - only those that are marked as persistent. Note also that marking a message as persistent has no effect if it is sent to a queue that is non-durable. A message must be marked as persistent and sent to a durable queue to be persistent.