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Maintaining a queue manager

 

From time to time, you might need to perform maintenance on a queue manager that is part of a cluster. For example, you might need to take backups of the data in its queues, or apply fixes to the software. If the queue manager hosts any queues, its activities must be suspended. When the maintenance is complete, its activities can be resumed.

To suspend a queue manager, issue the SUSPEND QMGR command, for example:

SUSPEND QMGR CLUSTER(SALES)

This sends a notification to the queue managers in the cluster SALES advising them that this queue manager has been suspended. The purpose of the SUSPEND QMGR command is only to advise other queue managers to avoid sending messages to this queue manager if possible. It does not mean that the queue manager is disabled. While the queue manager is suspended the workload management routines avoid sending messages to it, other than messages that have to be handled by that queue manager. Messages that have to be handled by that queue manager include messages sent by the local queue manager.

WebSphere MQ uses a workload balancing algorithm to determine which destinations are suitable, rather than selecting the local queue manager whenever possible. For more information about the workload management algorithm, see Using clusters for workload management.

When the maintenance is complete the queue manager can resume its position in the cluster. It should issue the command RESUME QMGR, for example:

RESUME QMGR CLUSTER(SALES)

This notifies to the full repositories that the queue manager is available again. The full repository queue managers disseminate this information to other queue managers that have requested updates to information concerning this queue manager.

We can enforce the suspension of a queue manager by using the FORCE option on the SUSPEND QMGR command, for example:

SUSPEND QMGR CLUSTER(SALES) MODE(FORCE)

This forcibly stops all inbound channels from other queue managers in the cluster. If you do not specify MODE(FORCE), the default MODE(QUIESCE) applies.

 

Parent topic:

Cluster-administration considerations

qc11300_

 

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