What happens when a repository fails

How you know a repository has failed and what to do to fix it?


Problem

  1. Cluster information is sent to repositories (whether full or partial) on a local queue called SYSTEM.CLUSTER.COMMAND.QUEUE. If this queue fills up, perhaps because the queue manager has stopped working, the cluster-information messages are routed to the dead-letter queue.
  2. The repository runs out of storage.


Solution

  1. Monitor the messages on your queue manager log or z/OS system console to detect if SYSTEM.CLUSTER.COMMAND.QUEUE is filling up. If it is, we need to run an application to retrieve the messages from the dead-letter queue and reroute them to the correct destination.
  2. If errors occur on a repository queue manager, messages tell you what error has occurred and how long the queue manager waits before trying to restart.

    • On IBM MQ for z/OS, the SYSTEM.CLUSTER.COMMAND.QUEUE is disabled for MQGET.
    • When you have identified and resolved the error, enable the SYSTEM.CLUSTER.COMMAND.QUEUE so that the queue manager can restart successfully.

  3. In the unlikely event of the repository running out of storage, storage allocation errors are sent to the queue manager log or z/OS system console. To fix the storage problem, stop and then restart the queue manager. When the queue manager is restarted, more storage is automatically allocated to hold all the repository information.

Parent topic: Queue manager clusters troubleshooting