For a WebSphere® MQ queue manager to connect with a WebSphere Application Server messaging engine in a highly available manner, you must install the WebSphere MQ MR01 SupportPac™. Alternatively, you can use an external high availability framework.
A WebSphere MQ link connects a service integration messaging engine to a WebSphere MQ queue manager. To WebSphere MQ, the messaging engine appears to be another queue manager.
The WebSphere MQ queue manager uses one IP address and one port to reach the messaging engine. In a high availability configuration, if the messaging engine fails over to a different server, the connection between the WebSphere MQ queue manager and the messaging engine would break.
The WebSphere MQ MR01 SupportPac provides the WebSphere MQ queue manager with a list of alternative IP addresses and ports so that a WebSphere MQ queue manager can connect with the messaging engine after failover.
If you install the WebSphere MQ MR01 SupportPac, the WebSphere MQ queue manager can reach the messaging engine after failover to a different IP address and port. When you install the WebSphere MQ MR01 SupportPac, set a high availability policy of "One of N" for the gateway messaging engine. For more information about the WebSphere MQ MR01 SupportPac, see MR01: Creating a HA Link between WebSphere MQ and a Service Integration Bus.