PM52570: CICS DOES NOT AUTOMATICALLY RECONNECT TO THE MQ QUEUE MANAGER AFTER THE MQ QM IS STOPPED AND RESTARTED W 12/01/24 PTF PEREMOVE

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• After applying PTF UK68064 , CICS no longer reconnects to
  the MQ queue manager when the queue manager is stopped and
  restarted while CICS remains up.
  .
  Here is an example of the messages issued by CICS when the
  queue manager is stopped:
  .
  DFHMQ0341 I STOP requested by alert monitor CKAM.
  DFHMQ0107 I A request to end CKTI has been received. CKTI ended.
  DFHMQ0334 I Adapter shutdown successful.
  DFHMQ0342 I CONNECT received from alert monitor.
  DFHMQ0324 I All queue managers in queue sharing group MQSG are
  inactive.
  DFHMQ0308 I Queue manager MQM1 is stopped. Connect request
  deferred.
  DFHMQ0364 I Monitor terminated normally.
  .
  The last of those messages, DFHMQ0364 , is the one that
  shouldn't be occurring.  It shows that the Alert Monitor task,
  CKAM , is terminated.  But that task should not be terminated
  at this point.  It is the task that would be able to detect
  when the Queue Manager is restarted.
  

Local fix

• Back off UK68064
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICS users.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: A customer using a CICS/MQ Queue        *
  *                      Sharing Group (QSG) sees messages       *
  *                      DFHMQ0324 and DFHMQ0308 during startup  *
  *                      even though the QSG Queue Manager is    *
  *                      available.  Additionally an attempt to  *
  *                      perform a warm shutdown of CICS is      *
  *                      unsuccessful and when a Queue Manager   *
  *                      attached to a CICS System is brought    *
  *                      down, it does not automatically         *
  *                      re-connect to the CICS system when it   *
  *                      is brought back up again.               *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  Whilst re-starting a CICS region which attaches to WMQ via a
  QSG, even though there is a QSG queue manager running and
  available, DFHMQCON issues message DFHMQ0324 indicated that it
  could not find an available queue manager.  This module then
  issues a series of DFHMQ0308 messages, and occasionally the
  CKAM task abends AEIP, before eventually DFHMQCON completes a
  successful reconnect to the Queue Manager.  Additionally, a
  warm keypoint sometimes cannot be taken at shutdown because the
  shutdown assist transaction CESD is required to purge the CKAM
  task.
  
  Also when the WMQ Queue Manager has been shutdown and
  restarted, DFHMQMON may not reactivate the adapter connection
  because the CKAM task was inadvertently purged during shutdown.
  
  Additional keywords: ABENDAEIP, msgDFHMQ0324, msgMQ0324,
  msg0324, msgDFHMQ0308, msgMQ0308, msg0308, DFHMQ0364,
  msgDFHMQ0364, msgMQ0364, msg0364, hang.
  

Problem conclusion

• DFHMQCON has been modified such that following the two calls to
  EXEC CICS START TRANID(CKAM), a new clause is added to ensure a
  second CKAM task which would prevent a successful warm shutdown
  is not inadvertently started.
  
  In module DFHMQDSC, procedure disconnect_from_mqm, has been
  modified such that dfhmqloa.cNoOfPendingEve is set to zero if
  and only if CICS is shutting down.  This ensures that the
  automatic reconnect to the Queue Manager is successful on Queue
  Manager restart.
  

Temporary fix

• FIX AVAILABLE BY PTF ONLY
  

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

  PM46338

• APAR is sysrouted TO one or more of the following:

  UK75952

Modules/Macros

•    DFHMQCON DFHMQDSC
  

Fix information

• Fixed component name

  CICS TS Z/OS V4

• Fixed component ID

  5655S9700

Applicable component levels

• R700 PSY UK75952

     UP12/02/18 P F202

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.