PH39940: OBJECT CREATE REQUESTS COUNT IS NOT INCREMENTED FOR SHARED DYNAMIC QUEUES

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• The Object Create requests count is incremented whenever a
  model queue is opened to create a dynamic queue (whether
  temporary or permanent).
  
  However, it was observed that for shared dynamic queues the
  Object Create requests count is zero while the Object Delete
  requests count has high number recorded.
  
  IBM MQ Development: z/OS service team has found a code path
  which can result in this scenario which applies to shared
  dynamic queues only.
  Consider this scenario with QM1 and QM2 being in a queue
  sharing group:
  
  1. APP1 opens shared queue SQ1 on QM1
  2. APP1 opens a DEFTYPE(SHAREDYN) model queue on QM1, resulting
  in shared dynamic queue DYNSQ1 being created
  3. APP1 puts a request message to SQ1 on QM1 and waits for the
  reply on queue DYNSQ1 on QM1
  4. APP2 gets the request message from SQ1 on QM2, and processes
  it
  5. APP2 opens and puts the reply message to the reply queue
  DYNSQ1 on QM2
  6. APP1 gets the reply message and closes and deletes DYNSQ1
  
  This scenario will result in the objects deleted count being
  incremented on both QM1 and QM2, however, the objects created
  count will only be incremented on QM1.
  
  The reason that this happens is that when the shared dynamic
  queue is created and opened on QM1, an XCF notification is sent
  to the other QMGRs in the queue sharing group to notify them
  about the new queue. This results in a worker task on QM2
  creating the queue IVSA, but the code path which it takes does
  not increment the objects created count. When the object is
  closed and deleted on QM1, this again results in an XCF
  notification being sent to the other QMGRs in the queue sharing
  group. This will again drive a worker task on QM2, however in
  this scenario, the code path taken will correctly increment the
  objects deleted count.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of IBM MQ for z/OS Version 9       *
  *                 Release 1 Modification 0 and Release 2       *
  *                 Modification 0.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: The object create requests and object   *
  *                      delete requests values in SMF may be    *
  *                      inconsistent.                           *
  ****************************************************************
  When a shared dynamic queue is opened, the object create
  requests count is only incremented on the current QMGR, while
  the object delete requests count is incremented on all QMGRs in
  the QSG.
  

Problem conclusion

• The incrementing of object delete requests has been changed to
  ensure consistency between this and the object create requests
  count.
  

Temporary fix

Comments

APAR Information

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

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

  UI80531

Modules/Macros

• CSQICDSQ
  

Fix information

• Fixed component name

  IBM MQ Z/OS V9

• Fixed component ID

  5655MQ900

Applicable component levels

• R200 PSY UI80531

     UP22/06/29 P F206

Fix is available

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