PH06084: MQ Z/OS: ABENDS OCCUR WHEN DELETE PSID IS ISSUED FOR A PAGE SET WITH DATA STILL BEING WRITTEN TO THE PAGE SET

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• The queue manager is terminating after dumps with symptoms that
  include:
  
  - TITLE: COMPON=IOS,COMPID=SC1C3,ISSUER=IOSVIRBA,IRBAFRR
  
    PIDS/5752SC1C3 RIDS/NUCLEUS#L RIDS/IOSVIRBA AB/S00C4
    PRCS/00000011 REGS/0F16C REGS/C166C RIDS/IOSVIRBA#R
  
    with the PSW in ICYDIE+016C or a similar offset with
    failing instruction: D506 4000 C050
  
  - Title: COMPON=MEDIA MANAGER, COMPID=DF126, ISSUER=ICYFRR
  
    PIDS/5695DF126 RIDS/IEANUC01#L RIDS/ICYPGAD AB/S00C6
    PRCS/00341114 REGS/FE000 RIDS/ICYFRR#R
  
    The ABEND0C6 is a bad branch from ICYPGAD due to a bad Reg15.
    There looks like an overlay of an MMPB or MMTB control
    block.
  
  - CSQP032I Page set <nn> deletion completed
  
    CSQY291E CSQWDSDM SDUMPX FAILED,
     RC=00000208,CSQE,ABN=0C4-00300614,PSW=070C0000CF4F4F4E
  
    CSQV086E QUEUE MANAGER ABNORMAL TERMINATION REASON=00E80100
  
  
  Media Manager support observed that MQ module CSQPDWP2
  started IO by calling MMCALL.  Before the IO was complete
  CSQPDWP2 closed the data set with a MMSRV DISCONNECT.  T
  
  This timing problem occurs when DELETE PSID(x) has been issued
  for a pageset which still has page contents in the bufferpool
  that hasn't been written to the pageset. At the time of the
  delete processing, the deferred write processor task for the
  pageset is actively writing the remaining pages. Part of the
  delete processing in CSQPFSET has logic which should ensure
  that all I/O is completed before the pageset is disconnected.
  However, in the failure cases this does not seem to work
  correctly, and the disconnect is issued to Media Manager before
  all the I/O is complete. This results in Media Manager freeing
  control blocks related to the dataset. The abend occurs when
  the active I/O processing attempts to use the deleted control
  blocks.
  
  
  Additional Symptom(s) Search Keyword(s):
  ABEND0C4 ABENDS0C4 0C4 S0C4 S00C4
  ABEND0C6 ABENDS0C6 0C6 S0C6 S00C6
  IOSVIRBA ICYFRR ICYDIE ICYPGAD
  reason code 00E80100
  

Local fix

• Avoid dynamically deleting a page set until a fix is available.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of IBM MQ for z/OS Version 9       *
  *                 Release 0 Modification 0 and Release 1       *
  *                 Modification 0.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: ABENDs occur when DELETE PSID is issued *
  *                      for a page set with data still being    *
  *                      written to it.                          *
  ****************************************************************
  DELETE PSID(x) is issued for a pageset which still has page
  contents in the bufferpool that haven't been written to the
  pageset. At the time of the delete processing, the deferred
  write processor task for the pageset is actively writing the
  remaining pages.
  The delete processing in CSQPFSET waits until the deferred write
  queue has been cleared before proceeding to disconnect. However
  in the reported problem, although the deferred write queue has
  been cleared, some of the resultant I/O is still in progress
  when the disconnect is issued to Media Manager. This results in
  Media Manager freeing control blocks related to the dataset. The
  ABEND occurs when the active I/O processing attempts to use the
  deleted control blocks.
  

Problem conclusion

• CSQPFSET has been updated to ensure all outstanding
  I/O for a DELETE PSID command has finished before the delete is
  issued.
  

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:

  UI60963 UI60964

Modules/Macros

• CSQPFSET
  

Fix information

• Fixed component name

  IBM MQ Z/OS V9

• Fixed component ID

  5655MQ900

Applicable component levels

• R000 PSY UI60963

     UP19/02/28 P F902 ¢

• R100 PSY UI60964

     UP19/02/28 P F902 ¢

Fix is available

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