7.3.4. Asynchronous Receive and Link Reliability

Bear in mind that the combination of asynchronous receive (prefetch) and an unreliable link is a potentially lossy situation. Over an unreliable link, when an application is consuming (as opposed to browsing the queue) the broker deletes the message from the queue as soon as it is prefetched. It does not wait for acknowledgement from the consumer. If the consumer fails before it dispatches prefetched messages, the broker will not redeliver them.

When using this combination - asynchronous receive (prefetch) and unreliable link - be aware of the implications.