The handle to the session that you want to recover.
You can only call this function for sessions that are not transacted. To rollback message delivery for a transacted session, use the MQRollBackSession() function. This function may be most useful if you use the MQ_CLIENT_ACKNOWELDGE mode.
All consumers deliver messages in a serial order. Acknowledging a received message automatically acknowledges all messages that have been delivered to the client.
Restarting a session causes it to take the following actions:
Stop message delivery in this session.
Mark all messages that might have been delivered but not acknowledged as redelivered.
Restart the delivery sequence including all unacknowledged messages that had been previously delivered. (Redelivered messages might not be delivered in their original delivery order.)