Configure a shared input queue for message flows
The WebSphere Message Broker broker makes use of WebSphere MQ queue-sharing groups on z/OS.
Queue managers that can access the same set of shared queues form a group called a queue-sharing group (QSG) and they communicate with each other by means of a coupling facility (CF) that stores the shared queues. A shared queue is a type of local queue whose messages can be accessed by one or more queue managers that are in a QSG.
To further enhance the availability of messages in a QSG, WebSphere MQ detects if another queue manager in the group disconnects from the CF in an unusual way, and completes pending units of work for that queue manager where possible; this is known as peer recovery.
Define a serialization token
Define the same value for the serialization token attribute for each MQInput node that is required to access the shared queue.
If you do not do this, when an MQInput node attempts to get a message from the shared queue, the action fails with the WebSphere MQ return code 2048(MQRC_PERSISTENT_NOT_ALLOWED)
This is to avoid input messages that are in progress being sent to the Dead Letter Queue because, during recovery, a message is restored to the input queue before another broker is able to get it and resume processing.