MQ

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  • 1.  MQ 9.2.0.5 and SYSTEM.CLUSTER.REPOSITORY.QUEUE

    Posted Fri May 27, 2022 12:55 PM
    Hello, 

    Today, I had a surprise regarding QMGR behavior. I won't bother you with the need I had to do the following. I know it's unusal and strictly not recommended, but I had to do it.
    I tried to dump the content of SYSTEM.CLUSTER.REPOSITORY.QUEUE but I got a 2042, object in use. I felt strange, because I used to do it one time before in an earlier version on MQ.
    So i decided to kill handling process amqrrmfa, direct punishment, qmgr ended unexpectedly. More efficient than killing xma0...
    I tried to start -ns, but same conclusion 2042...


    Question : Why is it now impossible to clear SYSTEM.CLUSTER.REPOSITORY.QUEUE ?

    ------------------------------
    Guillaume GELB
    ------------------------------


  • 2.  RE: MQ 9.2.0.5 and SYSTEM.CLUSTER.REPOSITORY.QUEUE

    IBM Champion
    Posted Mon May 30, 2022 12:37 AM
    Edited by Morag Hughson Mon May 30, 2022 12:37 AM

    Hi Guillaume,

    The following steps worked for me.

    1. ALTER QLOCAL(SYSTEM.CLUSTER.REPOSITORY.QUEUE) GET(DISABLED)
    2. endmqm -w MQG1
    3. strmqm MQG1

    At this point if you look in the queue manager AMQERR01.LOG you will see the following two error messages:

    AMQ9510E: Messages cannot be retrieved from a queue.
    
    EXPLANATION:
    The attempt to get messages from queue 'SYSTEM.CLUSTER.REPOSITORY.QUEUE' on
    queue manager 'MQG1' failed with reason code 2016.

    AMQ9448E: Repository manager failed. Retry in 10 minutes, queue manager will
    terminate in 7200 minutes
    
    EXPLANATION:
    Repository manager encountered a severe problem. See the earlier messages in
    the queue manager or system error logs for details. The repository manager
    will retry the command in 10minutes. If the problem is not rectified in 7200
    minutes the queue manager will terminate. Until this problem is rectified no
    further cluster management activity will occur, this will affect the
    availability of cluster resources accessed or hosted by this queue manager.
    1. At this point I now had 10 minutes uninterrupted to do the task at hand.
    2. ALTER QLOCAL(SYSTEM.CLUSTER.REPOSITORY.QUEUE) GET(ENABLED)
    3. And now I can dump the contents of the queue:
      qload -m MQG1 -i SYSTEM.CLUSTER.REPOSITORY.QUEUE -f *
    4. After 10 minutes my repository manager started up again and all was well.
    AMQ9449I: The repository manager is restarting following an error.
    
    EXPLANATION:
    The repository manager is restarting following an error, see earlier error
    messages for details of the failure.

    Instead of trying to stop the repository manager, I instead caused the repository manager not be able to successfully start. Small differences, but it worked for me.

    Cheers,
    Morag



    ------------------------------
    Morag Hughson
    MQ Technical Education Specialist
    MQGem Software Limited
    Website: https://www.mqgem.com
    ------------------------------



  • 3.  RE: MQ 9.2.0.5 and SYSTEM.CLUSTER.REPOSITORY.QUEUE

    Posted Mon May 30, 2022 02:32 AM
    Hello Morag,

    Thanks for tip. I will try it soon. But I think something changed since the newests releases... Because earlier binaries did not behave like that.

    ------------------------------
    Guillaume GELB
    ------------------------------



  • 4.  RE: MQ 9.2.0.5 and SYSTEM.CLUSTER.REPOSITORY.QUEUE
    Best Answer

    IBM Champion
    Posted Tue August 23, 2022 02:49 PM

    It is quite likely that the robustness of the queue manager has been improved so that if the repository manager is not running, then the queue manager comes down. It is such an important part of the queue manager that perhaps it is now considered critical where before it was not. Is this what you are referring to?

    If your comment about the change in behaviour is about something else, please be explicit so further comment can be made.

    Cheers,
    Morag



    ------------------------------
    Morag Hughson
    MQ Technical Education Specialist
    MQGem Software Limited
    Website: https://www.mqgem.com
    ------------------------------



  • 5.  RE: MQ 9.2.0.5 and SYSTEM.CLUSTER.REPOSITORY.QUEUE

    Posted Tue May 31, 2022 12:16 PM
    Yes Morag,
    You replied perfectly !

    ------------------------------
    Guillaume GELB
    ------------------------------



  • 6.  RE: MQ 9.2.0.5 and SYSTEM.CLUSTER.REPOSITORY.QUEUE

    IBM Champion
    Posted Tue May 31, 2022 03:38 PM
    This is interesting.
    I did not see this change in the announcement of MQ. Nor i see in the documentation.

    ------------------------------
    om prakash
    ------------------------------



  • 7.  RE: MQ 9.2.0.5 and SYSTEM.CLUSTER.REPOSITORY.QUEUE

    IBM Champion
    Posted Tue May 31, 2022 06:33 PM

    I wouldn't expect this level of detail to appear in an announcement letter. They are very much the broad brush description of the release.

    The documentation describes it here: Changes to cluster error recovery

    Cheers,
    Morag



    ------------------------------
    Morag Hughson
    MQ Technical Education Specialist
    MQGem Software Limited
    Website: https://www.mqgem.com
    ------------------------------