You can configure JMS to run in Transacted or Non-Transacted mode.

When you configure JMS to run in Transacted mode, the PowerCenter Integration Service receives and processes a group of JMS messages as a transaction. The PowerCenter Integration Service acknowledges all the messages by committing the transaction. If a transaction rolls back, the JMS provider returns all the uncommitted messages in that particular transaction to the recovery queue configured for the JMS application connection or the default cache folder $PMCacheDir\.

When you configure MS to run in Non-Transacted mode, the PowerCenter Integration Service uses the CLIENT_ACKNOWLEDGE method to acknowledge messages. When the PowerCenter Integration Service acknowledges one message in the JMS session, then all the messages are acknowledged by default. PowerCenter JMS sessions run in Non-Transacted mode by default.

Configure Transacted mode for JMS sessions on the Mapping tab for a JMS session. Click SQ_JMSReader in the left panel. Updated JMS sources have Transacted mode disabled by default.