PH50491: MQ Z/OS: ABN=5C6-00E512A1,U=CSQ1CHIN,C=MQ900.920.ASMC-CSQVSRX , M=CSQ VSRRX,LOC=CSQVSRX .CSQVSRRX

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• The CHIN job received a dump for:
  ABN=5C6-00E512A1,U=CSQ1CHIN,C=MQ900.920.ASMC-CSQVSRX
  ,M=CSQVSRRX,LOC=CSQVSRX .CSQVSRRX
  
  The queue manager failed with:
  CSQV086E QUEUE MANAGER ABNORMAL TERMINATION REASON=00E50054
  
  
  Reason code 00E512A1 is a diagnostic reason code that was added
  at MQ 9.0.0 and 9.1.0 by PH12062 to detect a protocol violation
  for the ROB control block.
  
  The PSW for the abend is in CSQVSRX in routine StateError,
  which was called by routine HANDLEBADSTATE.
  
  The ABEND5C6-00E512A1 was issued during a suspend from CSQVSRX
  after an attempt to deallocate a Pause Element Token (PET)
  failed with IEA_PE_BAD_STATE. The deallocation failed because
  the PET was in use by another task. The PET is contained within
  the ROB. Each task should have its own ROB and EB control
  blocks, but in this case, two channel tasks were using the same
  ROB and EB.
  
  The root cause of the problem is a timing window when a SVRCONN
  channel is using the CSQSERVICE1 XA compatibility mode. The
  timing window occurs when one conversation for the channel is
  doing an XA_PREPARE, and another conversation is issuing
  another XA request at the same time for the same XID.
  .
  Other symptoms might occur as a result of the timing problem,
  for example:
  5C6-00E50076 from CSQVEUS1
  

Local fix

• N/A
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of IBM MQ for z/OS Version 9       *
  *                 Release 2 Modification 0 and                 *
  *                 Release 3 Modification 0.                    *
  ****************************************************************
  * PROBLEM DESCRIPTION: When a SVRCONN channel is using the     *
  *                      CSQSERVICE1 XA compatibility mode the   *
  *                      following abends may be seen:           *
  *                                                              *
  *                       - 5C6-00E512A1                         *
  *                       - 5C6-00E50076                         *
  *                                                              *
  *                      This then leads to QMGR termination.    *
  *                                                              *
  *                      Additionally at V930 the following      *
  *                      abend is seen when QMGR trace is turned *
  *                      ON in module CSQMXARH:                  *
  *                                                              *
  *                       - 0C4-00000011                         *
  ****************************************************************
  When a SVRCONN channel is using the CSQSERVICE1 XA compatibility
  mode a timing window can occurs when one conversation for the
  channel is doing an XA_PREPARE, and another conversation is
  issuing another XA request at the same time for the same XID.
  This results in either an 5C6-00E512A1 or 5C6-00E50076 abend or
  both depending on the current latch contention for the Unit Of
  Work.
  
  Additionally at V930 an 0C4-00000011 abend in CSQMXARH will be
  seen if QMGR trace is turned ON for the same scenario as above.
  It is caused by a programming error in the trace collection
  routine after an XA_ROLLBACK api call has completed.
  

Problem conclusion

• The code has been corrected to remove the timing window causing
  the 5C6 abends by correcting the serialisation on the XID within
  the QMGR.
  
  Additionally the code causing the 0C4-00000011 abend at V930
  has been corrected.
  

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:

Modules/Macros

• CSQMXARH CSQWTSFN
  

Fix information

• Fixed component name

  IBM MQ Z/OS V9

• Fixed component ID

  5655MQ900

Applicable component levels

• R200 PSY UI83899

     UP23/02/04 P F302 ¢

• R300 PSY UI83898

     UP23/02/04 P F302 ¢

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.