PH61586: ISSUE WITH THE EFFICIENT USAGE OF ABOVE-THE-BAR STORAGE DURING THE PEER LEVEL RECOVERY PROCESSING

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• The customer has reported an issue where a queue manager
  failure which resulted in other members of the QSG attempting
  to perform PLR of the application structure state on behalf of
  the failed queue manager. This has resulted in all the queue
  managers getting out of memory error with 'CSQY227E -Unable to
  allocate storage above the bar using IARV64, RC=00000008,
  reason=4A001620' and ABN=5C6-00E20045.
  

Local fix

• Increase the MEMLIMIT
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of IBM MQ for z/OS Version 9       *
  *                 Release 2 Modification 0,                    *
  *                 Release 3 Modification 0 and                 *
  *                 Release 4 Modification 0.                    *
  ****************************************************************
  * PROBLEM DESCRIPTION: When a queue manager in a QSG           *
  *                      terminates abnormally, other queue      *
  *                      managers in the QSG issue errors:       *
  *                      "                                       *
  *                      CSQY224I +XXXX CSQSCTL Queue manager is *
  *                      short of local storage above the bar    *
  *                      "                                       *
  *                      "                                       *
  *                      CSQY225E +XXXX CSQSCTL Queue manager is *
  *                      critically short of local storage above *
  *                      the bar - take action                   *
  *                      " and                                   *
  *                      "                                       *
  *                      CSQY227E +XXXX CSQSQC64 Unable to       *
  *                      allocate storage above the bar using    *
  *                      IARV64, RC=00000008, reason=4A001620    *
  *                      "                                       *
  *                      This can be accompanied by abend        *
  *                      5C6-00E20045 in CSQILPLM.CSQIUOWA.      *
  ****************************************************************
  During Peer Level Recovery (PLR) for a failed queue manager's
  connection to a structure, CSQERWI1 will sometime need to
  read the queue manager logs for the failed Peer to determine
  the logged state of a unit of work.
  While doing this, storage is obtained for a copy of control
  blocks representing the operations performed on shared queues
  as well as the overall state of the unit of work. The storage
  used for the operations is obtained from a 4K aligned PHB, so
  each such block is a minimum of 4K.
  When there are a large number of units of work that were either
  in progress at the last checkpoint, or were started since, the
  amount of storage required can be substantial, leading to
  a Short on Storage condition and the reported errors if there
  is insufficient 64 bit storage available to the queue manager.
  

Problem conclusion

• Processing is amended to only allocate the storage necessary to
  track the state of each unit of work.
  

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:

  UI98391 UI98392 UI98393

Modules/Macros

• CSQELPRC CSQEPRAD CSQERWI1 CSQILPRC
  

Fix information

• Fixed component name

  IBM MQ Z/OS V9

• Fixed component ID

  5655MQ900

Applicable component levels

• R200 PSY UI98393

     UP24/09/25 P F409 ¢

• R300 PSY UI98392

     UP24/09/25 P F409 ¢

• R400 PSY UI98391

     UP24/09/25 P F409 ¢

Fix is available

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