Sun Java System Message Queue 4.3 Administration Guide

Acknowledgment Mode

One mechanism for ensuring the reliability of JMS message delivery is for a client to acknowledge consumption of messages delivered to it by the Message Queue broker.

If a session is closed without the client acknowledging the message or if the broker fails before the acknowledgment is processed, the broker redelivers that message, setting a JMSRedelivered flag.

For a nontransacted session, the client can choose one of three acknowledgment modes, each of which has its own performance characteristics:

(Using CLIENT_ACKNOWLEDGE mode is similar to using transactions, except there is no guarantee that all acknowledgments will be processed together if a provider fails during processing.)

Acknowledgment mode affects performance for the following reasons: