PH63803: MQ 940: 0C4-04 ABEND IN AMS DURING QMGR TERMINATION FROM CF CONN LOSS

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• The 0C4 occurs when CSQ0DSRV attempts to set the
  cbFlagsAMS.fStopped flag in PG0BL. During normal queue manager
  shutdown, the queue manager will wait until cbFlagsAMS.fStopped
  is set before continuing its shut down and freeing the G0BL. In
  the case of an abnormal queue manager termination, the queue
  manager does not wait for this flag to be set, causing a race
  condition where G0BL may get freed before cbFlagsAMS.fStopped is
  set. If this happens, an 0C4 can occur in the AMS Address Space.
  (Pre-GHE APAR) UHL LINK:
  https://jazza06.hursley.ibm.com:9443/ccm/resource/itemName/com.i
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of IBM MQ for z/OS Version 9       *
  *                 Release 4 Modification 0.                    *
  ****************************************************************
  * PROBLEM DESCRIPTION: Various symptoms in the xxxxAMSM        *
  *                      address space following abnormal queue  *
  *                      manager termination, including:         *
  *                      - Termination with abend S0C4           *
  *                      - Message "CSQY270E xxxx SQFSAMG        *
  *                        UNRECOGNIZED MESSAGE NUMBER CSQ0699"  *
  ****************************************************************
  During abnormal queue manager termination, the AMS address space
  is notified of the termination and shuts down. During AMS
  termination, an attempt is made to reference control blocks
  allocated by the queue manager, that were freed when it
  terminated, leading to the reported symptoms.
  

Problem conclusion

• The AMS address space no longer attempts to reference the
  affected control blocks following abnormal queue manager
  termination.
  

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:

  UO04567 UO04568 UO04569 UO04570 UO04571 UO04572

Modules/Macros

• CSQ0DCNS CSQ0DSRV CSQ0DSVC CSQ0IPRH CSQ0LF0T CSQ0STRT CSQ0UTRC
  CSQF0TXC CSQF0TXE CSQF0TXF CSQF0TXK CSQF0TXU
  

Fix information

• Fixed component name

  IBM MQ Z/OS V9

• Fixed component ID

  5655MQ900

Applicable component levels

• R400 PSY UO04567

     UP25/09/13 P F509

• R401 PSY UO04568

     UP25/09/13 P F509

• R402 PSY UO04569

     UP25/09/13 P F509

• R403 PSY UO04570

     UP25/09/13 P F509

• R404 PSY UO04571

     UP25/09/13 P F509

• R405 PSY UO04572

     UP25/09/13 P F509

Fix is available

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