PH27803: MQ QUEUE MANAGER DOES NOT QUIESCE AFTER STOP QMGR, THEN CANCEL, AND FORCE ARE DONE

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• After concurrent issues within other system applications it is
  necessary to issue a STOP against MQ. The queue manager does
  not quiesce. Subsequently, z/OS CANCEL and FORCE commands
  issued against the MQ subsystem also are unable to terminate
  it, resulting in a necessary IPL. The SRM state of MQ is left
  as "CANCEL IN PROGRESS", as MQ continues to hold an ENQueue
  against resource SYSZCSQ3 ERLYOLRH.
  .
  Additional keywords:
  ACECHNA loop
  .
  After this APAR is applied, if a loop is detected, the queue
  manager terminates with
  CSQV086E QUEUE MANAGER ABNORMAL TERMINATION REASON=00F30908
  and
  IEF450I ABEND=S6C6 U0000 REASON=00F30908
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of IBM MQ for z/OS Version 9       *
  *                 Release 0 Modification 0, Release 1          *
  *                 Modification 0 and Release 2 Modification 0. *
  ****************************************************************
  * PROBLEM DESCRIPTION: Various problems encountered when an    *
  *                      application connected to a queue        *
  *                      manager are terminated abnormally (for  *
  *                      example, Cancel, Force, Memterm).       *
  *                      Symptoms can include:                   *
  *                      - High CPU usage in the application,    *
  *                        queue manager, or MASTER address      *
  *                        space                                 *
  *                      - Application and/or Queue manager      *
  *                        address spaces do not end, and cannot *
  *                        be canceled or forced                 *
  *                      - Other applications hang waiting for   *
  *                        resources held by MQ                  *
  *                      In extreme cases an IPL is required to  *
  *                      resolve the problem.                    *
  ****************************************************************
  A loop was introduced into the VLCAAACE chain for an application
  address space. The cause of the loop is unknown.
  
  When the application goes through end of memory processing, or
  when the queue manager is abnormally terminated, the VLCAAACE
  chain(s) are scanned for any ACEs that require cleaning up.
  
  However due to the loop in the chain, this processing (which
  can occur in the application address space, queue manager
  address space, or MASTER (0001) address space, began looping
  indefinitely.
  

Problem conclusion

• MQ End of Memory and Termination processing are changed to
  detect unexpected loops in the VLCAAACE chains.
  In the event of a loop being found, the queue manager is
  terminated abnormally, preventing the error impacting on other
  applications/services on the system.
  

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:

  UI72157 UI72158 UI73202

Modules/Macros

• CSQ3SSI1 CSQ3SSI2 CSQVATRM
  

Fix information

• Fixed component name

  IBM MQ Z/OS V9

• Fixed component ID

  5655MQ900

Applicable component levels

• R000 PSY UI73202

     UP21/01/28 P F101

• R100 PSY UI72157

     UP P F011

• R200 PSY UI72158

     UP21/01/04 P F012

Fix is available

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