PH63204: MQ INCONSISTENT STATE FOLLOWING A CRESTART

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Following a system crash, an attempt to stop the QMGR and also
  to CANCEL it was tried, but neither had any observable effect.
  The Queue Manager just seemed to hang.
  
  An attempt to rebuild the in-memory index for a queue
  xxxxx.yyyyy.zzzzz which was indexed by MSGID took longer than
  expected. In the meantime, the MQ subsystem was CANCELLED,
  resulting in a S222 ABEND.
  Index-rebuilding continued, even after a CANCEL.
  Subsequent CANCELs do not have any effect.
  
   This is not the correct behavior - the QMGR should come down
  when it is cancelled and should not wait for index rebuilding
  to complete.
  
  This APAR addresses this change in logic.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of IBM MQ for z/OS Version 9       *
  *                 Release 3 Modification 0 and Release 4       *
  *                 Modification 0.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: The Queue Manager hangs in Queue Index  *
  *                      rebuild processing and a CANCEL will    *
  *                      not work on the MQ subsystem.           *
  ****************************************************************
  Corruption on a pageset causes Queue Index rebuild processing to
  endlessly loop through a number of the same records. The result
  is that the Queue Manager hangs until storage above the bar is
  exhausted and a CANCEL will not suffice to cancel the Queue
  Manager.
  

Problem conclusion

• Code has been added to detect an endless loop in the Queue Index
  rebuild process and a new abend will be taken to break out of
  the loop (5C6-00C90F03).
  
  The IBM MQ for z/OS Version 9.3.x and Version 9.4.x
  documentation are updated:
  
  IBM MQ
   Reference
    Messages and reason codes
     IBM MQ for z/OS messages, completion, and reason codes
      IBM MQ for z/OS codes
       Data Manager Codes (X'C9')
  
  9.3.x -> https://www.ibm.com/docs/en/ibm-mq/9.3.x?topic=codes-da
  ta-manager-xc9
  9.4.x -> https://www.ibm.com/docs/en/ibm-mq/9.4.x?topic=codes-da
  ta-manager-xc9
  
  00C90F03
  
  A chain loop was detected during queue index rebuild processing.
  
  System action
  
  The current execution unit terminates with completion code
  X'5C6', and a dump is produced.
  
  System programmer response
  
  Collect the items listed in Diagnostics and contact IBM Support.
  

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:

  UO04580 UO04581

Modules/Macros

• CSQIRBLD
  

Fix information

• Fixed component name

  IBM MQ Z/OS V9

• Fixed component ID

  5655MQ900

Applicable component levels

• R300 PSY UO04581

     UP25/09/13 P F509

• R400 PSY UO04580

     UP25/09/13 P F509

Fix is available

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