Restoring a queue manager to its pre-cluster state

When a queue manager is removed from a cluster, it retains knowledge of the remaining cluster members. This knowledge eventually expires and is deleted automatically. However, if you prefer to delete it immediately, we can use the steps in this topic.


Before starting

It is assumed that the queue manager has been removed from the cluster, and is no longer performing any work in the cluster. For example, its queues are no longer receiving messages from the cluster, and no applications are waiting for messages to arrive in these queues.


When a queue manager is removed from a cluster, it retains knowledge of the remaining cluster members for up to 90 days. This can have system benefits, particularly if the queue manager quickly rejoins the cluster. When this knowledge eventually expires, it is deleted automatically. However, there are reasons why you might prefer to delete this information manually. For example:

  • We might want to confirm that we have stopped every application on this queue manager that previously used cluster resources. Until the knowledge of the remaining cluster members expires, any such application continues to write to a transmit queue. After the cluster knowledge is deleted, the system generates an error message when such an application tries to use cluster resources.
  • When you display status information for the queue manager, you might prefer not to see expiring information about remaining cluster members.

This task uses the INVENTORY cluster as an example. The LONDON queue manager has been removed from the INVENTORY cluster as described in Removing a queue manager from a cluster. To delete knowledge of the remaining members of the cluster, issue the following commands on the LONDON queue manager.


Procedure

  1. Remove all memory of the other queue managers in the cluster from this queue manager: 
    REFRESH CLUSTER(INVENTORY) REPOS(YES)
  2. Monitor the queue manager until all the cluster resources are gone: 
    DISPLAY CLUSQMGR(*) CLUSTER(INVENTORY)
DISPLAY QCLUSTER(*) CLUSTER(INVENTORY)
DISPLAY TOPIC(*) CLUSTER(INVENTORY)

Parent topic: Configure a queue manager cluster


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