Sun Java System Message Queue 4.3 Developer's Guide for C Clients

Acknowledgement Mode

Other than using transactions, you can ensure reliable delivery by having the client acknowledge receiving a message. If a session is closed without the client acknowledging the message or if the message server fails before the acknowledgment is processed, the broker redelivers that message, setting the MQ_REDELIVERED_HEADER_PROPERTY message header.

For a non-transacted session, the client can choose one of three acknowledgement modes, each of which has its own performance characteristics:

Performance is impacted by acknowledgement mode for the following reasons:

In general, our tests show about a 7% difference in performance between pesistent and nonpersistent messages, no matter which acknowledgment mode is used. That is, while persistence is a significant factor affecting performance, acknowledgment mode is not.