Message Paging

Persistent and non-persistent messages consume server memory unless paging is enabled. Message paging is the process of freeing server memory for persistent and non-persistent messages, as even persistent messages cache their data in memory. A paged-out message does not free all of the memory that it consumes. The message header and message properties remain in memory for use with searching, sorting, and filtering. Messages sent in a transacted session are eligible for paging only after the session is committed. Before that, the message is held in memory.
Tips

1. If JMS paging is enabled and no paging store is configured, WLS 8.1 creates a paging store automatically, but configuring a paging store explicitly is recommended (you can specify the location of the store).

2. JMS paging increases the amount of message data a WebLogic Server instance can contain without requiring an increase in the JVM heap size.

3. Although paging does degrade performance, its effect is less when paging non-persistent messages than when paging persistent messages.

4. Always configure quotas for WebLogic JMS Servers; quotas prevent messages from overflowing server memory.