PH65320: DUMP TITLE= ABN=5C6 00E20045 U=,C=MQ900.940.DMC - CSQICRE2 ,M=CSQGFRCV,LOC=CSQILPLM. CSQICRE2 +000006E0

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• The S5C6-00E20045 abend occurred in CSQICRE2 when trying to get
  a block for STATQ processing from the "QStat block" 64-bit
  storage pool. The abend occurred because MEMLIMIT had been
  reached and an IARV64 call failed. The stack of the failing
  thread shows that it was opening a model queue, which requires
  creating a dynamic queue. Since the model queue has STATQ(QMGR)
  and the QMGR has STATQ(ON), a STATQ block is allocated. In
  64-bit storage usage of the QMGR can indicate a majority of
  storage being used to hold STATQ blocks for various objects.
  The problem is that these blocks are not freed when the object
  is deleted. This problem also applies to permanent and
  temporary dynamic queues. This amounts to a leak of around 900
  bytes per queue created.
  

Local fix

• Workaround can be done by disabling STATQ processing for model
  queues. This can be done by either turning off STATQ at the
  model queue level or at the QMGR level.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of IBM MQ for z/OS Version 9       *
  *                 Release 4 Modification 0                     *
  ****************************************************************
  * PROBLEM DESCRIPTION: A storage leak is caused by Queue       *
  *                      Statistics creating and not deleting    *
  *                      STATQ blocks for Dynamic Queues when    *
  *                      a model queue is opened.                *
  ****************************************************************
  Queue Statistics allocates ~900 bytes of storage for a STATQ
  block for each queue object with STATQ enabled. However when
  the queue objects are deleted, the STATQ blocks are not freed.
  
  When using Model Queues with STATQ enabled (either on the queue
  or queue manager), the creation on a dynamic queue when the
  model queue is opened caused a STATQ block to be allocated for
  the dynamic queue. When the queue was closed, and the dynamic
  queue deleted, the STATQ block would not be freed. Over time,
  this results in queue manager storage being exhausted as a new
  block would be allocated each time the model queue was opened.
  

Problem conclusion

• The code has been corrected to free STATQ blocks when an object
  is deleted.
  

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:

  UO02616

Modules/Macros

• CSQICRE2 CSQIDEL5
  

Fix information

• Fixed component name

  IBM MQ Z/OS V9

• Fixed component ID

  5655MQ900

Applicable component levels

• R400 PSY UO02616

     UP25/04/10 P F504 ¢

Fix is available

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