MQ JMS connection pooling
To improve the overall performance of JMS within the system, the message listener service enables the connection pooling facility provided by the MQ JMS implementation. This support does not affect the performance of a message listener, because it retains its connections while listening on a destination, but does affect the overall JMS system performance. When a connection is no longer required, MQ can pool the connection then reuse it later instead of destroying it.
This support is only available if MQ is configured as the JMS provider.