Creating a backout plan for queue manager cluster migration

Before performing a migration, decide on a backout plan in case of failure.


Before you begin

What backout capabilities do the queue managers in the cluster support?

If the libraries of the earlier level of IBM MQ include the appropriate PTFs to be able to backward migrate, and NEWFUNC mode is not enabled at the higher level, queue managers running on z/OS® can be reverted to an earlier level by changing the load libraries.

On other platforms, the only backout option is to restore a queue manager to a previous state. In restoring a queue manager, you lose any persistent changes since the queue manager started running at the new level.


The backout plan must consider how to maintain the availability of the cluster. It must deal with any issues arising from migrating a queue manager in the cluster.


Procedure

The backout plan must describe the following points:

  • What constitutes a successful migration.
  • The conditions that trigger the backout procedure.
  • Alternative backout actions, such as:
    1. Suspending a queue manager from the cluster.
    2. Backward migration
    3. Keeping a queue manager offline until an external issue is resolved.