IBM Support

IT09497: MQ EXPLORER 8.0: NOT ALL SETS OF QUEUE MANAGERS CAN BE FULLY EXPANDED AND SOME QUEUE MANAGERS ARE MISSING

Subscribe

You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • When using MQ Explorer 8.0 with many sets of queue managers in
    the left navigation panel, some of these sets fail to expand
    fully: some queue managers are shown, but other queue managers
    in the set are missing.
    

Local fix

Problem summary

  • ****************************************************************
    USERS AFFECTED:
    This issue affects users of the IBM MQ Explorer V8 who use Queue
    Manager Sets, and administer remote queue managers via an
    intermediate queue manager.
    
    
    Platforms affected:
    Windows, Linux on x86, Linux on x86-64
    
    ****************************************************************
    PROBLEM DESCRIPTION:
    When the IBM MQ Explorer starts up, a number of internal threads
    are created which look at all of the queue managers that the
    user interface has been configured to monitor, and register them
    with an internal data model. There is one internal thread for
    each queue manager that has been defined in the user interface.
    As part of the registration process, the internal threads
    associate the queue manager that they are registering with any
    Queue Manager Sets that the queue manager belongs to.
    
    While this processing was taking place, it was possible for a
    deadlock situation to occur between two internal threads which
    prevented any new queue managers from being registered with the
    IBM MQ Explorer. As a result of this, any queue managers that
    were successfully registered before the deadlock occurred would
    appear in any Queue Manager Sets that they had been assigned to.
    However, those queue managers that were still being registered
    at the time of the deadlock would not appear in any Queue
    Manager Sets.
    
    
    A Javacore taken when the deadlock occurred showed that the
    following two threads were involved:
    
    Thread 1:
    ---------------------------
    "WebSphere MQ creating : QM1"
    Blocked on: java/lang/Object@0xDCFFF8
    Owned by: "WebSphere MQ creating : QM2"
          Java callstack:
              at com/ibm/mq/explorer/core/internal/utils/
    CoreServices.sameTreeNameExists(CoreServices.java:2131)
                  (entered lock:
    com/ibm/mq/explorer/core/internal/utils/CoreServices@0xD34190)
              at com/ibm/mq/explorer/core/internal/objects/
    DmQueueManager.getTreeName(DmQueueManager.java:1530(Compiled
    Code))
              at com/ibm/mq/explorer/core/internal/objects/
    DmQueueManager.(DmQueueManager.java:516)
              at com/ibm/mq/explorer/core/internal/objects/
    CreateDmQueueManager.run(CreateDmQueueManager.java:160)
                  (entered lock: java/lang/Object@0x471D30)
    
    
    Thread 2:
    ---------------------------
    "WebSphere MQ creating : QM2"
    Blocked on:
    com/ibm/mq/explorer/core/internal/utils/CoreServices@0xD34190
    Owned by: "WebSphere MQ creating : QM1"
          Java callstack:
              at com/ibm/mq/explorer/core/internal/utils/
    CoreServices.getMatchingQueueManager(CoreServices.java:1625)
                  (entered lock: java/lang/Object@0xDCFFF8)
              at
    com/ibm/mq/explorer/core/internal/objects/DmQueueManager.
    connectUsingVia(DmQueueManager.java:1096)
              at com/ibm/mq/explorer/core/internal/objects/
    DmQueueManager.connectToQueueManager(DmQueueManager.java:785)
              at com/ibm/mq/explorer/core/internal/objects/
    DmQueueManager.init(DmQueueManager.java:612)
              at com/ibm/mq/explorer/core/internal/objects/
    DmQueueManager.connectSynchronously(DmQueueManager.java:2289)
              at com/ibm/mq/explorer/core/internal/objects/
    CreateDmQueueManager.run(CreateDmQueueManager.java:218)
    

Problem conclusion

  • The internal locking model used by the IBM MQ Explorer has been
    updated to ensure that the internal threads used to register
    queue managers with the internal data model hold all of the
    required locks before starting with the registration process.
    This ensures that the deadlock reported in the APAR no longer
    occurs.
    
    ---------------------------------------------------------------
    The fix is targeted for delivery in the following PTFs:
    
    Version    Maintenance Level
    v8.0       8.0.0.4
    
    The latest available maintenance can be obtained from
    'WebSphere MQ Recommended Fixes'
    http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006037
    
    If the maintenance level is not yet available information on
    its planned availability can be found in 'WebSphere MQ
    Planned Maintenance Release Dates'
    http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006309
    ---------------------------------------------------------------
    

Temporary fix

Comments

APAR Information

  • APAR number

    IT09497

  • Reported component name

    WMQ BASE MULTIP

  • Reported component ID

    5724H7251

  • Reported release

    800

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2015-06-17

  • Closed date

    2015-09-29

  • Last modified date

    2015-09-29

  • APAR is sysrouted FROM one or more of the following:

  • APAR is sysrouted TO one or more of the following:

Fix information

  • Fixed component name

    WMQ BASE MULTIP

  • Fixed component ID

    5724H7251

Applicable component levels

  • R800 PSY

       UP

[{"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSYHRD","label":"IBM MQ"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"8.0.0.0","Edition":"","Line of Business":{"code":"LOB36","label":"IBM Automation"}}]

Document Information

Modified date:
29 September 2015