A broker may be used as an intermediary to exchange messages between producers and consumers. The broker may store and dispatch messages from a physical queue stored in a persistent memory. More specifically, the broker may enqueue messages to the physical queue that are received from producers and may dispatch messages from the physical queue to interested consumers. The broker may further utilize one or more logical queues stored in transient memory to track the status of the messages stored in persistent memory. As messages are dispatched to and acknowledged by interested consumers, the broker deletes acknowledged messages from the physical queue. The messages deleted are those preceding a physical ACKlevel pointer that specifies the first non-acknowledged message in the physical queue. The physical ACKlevel pointer is advanced in the physical queue based on the relative position of corresponding logical ACKlevel pointers maintained by the logical queues.