PM45464: CICS-DB2 HANGS DURING DISCONNECTING AFTER A RECEIVING A DB2 ABEN D. CDBF TASK IS SUSPENDED IN DB2CDISC

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• If a task is taking an AD2U transaction dump and DFHD2TM issues
  a FORCEPURGE against this taskthen the FORCEPURGE can cause the
  queued transaction dump request to be aborted. This will cause
  an error to flow back to DFHD2EX1 which has requested the dump.
  However, DFHD2EX1 contains no code to detect the error so the
  FORCEPURGE can effectively get consumed by transaction dump
  processing without causing the task to abend.
  This timing error results in CICS-DB2 hanging while attempting
  to do a DISCONNECT as a result of the AD2U abend. The CBDF
  task will sit in a DB2CDISC from which it will not emerge
  Additional Keyword(s) - DB2CDISC, STANDBY , DUDU_DISASTER
  KIXREVEPH
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users                                    *
  ****************************************************************
  * PROBLEM DESCRIPTION: The CICS DB2 connection does not        *
  *                      disconnect after a DB2 subsystem        *
  *                      failure.                                *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  The CICS DB2 connection does not disconnect after a DB2
  subsystem failure.
  
  CDBF attempts to force purge those tasks that have called DB2,
  then waits on ECB DB2DISC for them all to complete, however
  this wait is never resumed.
  
  This is a result of two situations occurring
  1. the force purge of the user transaction is lost while
  the user transaction is taking a transaction dump for
  abend AD2U
  2. the user transaction continues executing after receiving
  a bad sql code such as -923 or -924.
  

Problem conclusion

• The CICS DB2 Attach mechanism has been changed to avoid
  requesting a transaction dump for a transaction that has
  been force purged by CDBF.
  
  The CICS Transaction Server V4.1 Supplementary Data Areas
  (GC34-7015-02) Section D2LOT CICS/DB2 Life of task block
  has been updated to add a new 01 bit in the reserved
  01 bit for byte lot_request_flags
  
  LOT_FORCE_PURGED .... ...1 Task force purged
  

Temporary fix

• FIX AVAILABLE BY PTF ONLY
  

Comments

APAR Information

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

  PM45520

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

  UK71882 UK71883

Modules/Macros

•    DESD2EX1 DESD2TM  DFHD2EX1 DFHD2LTC DFHD2LTD
  DFHD2TM
  

Fix information

• Fixed component name

  CICS TS Z/OS V4

• Fixed component ID

  5655S9700

Applicable component levels

• R600 PSY UK71882

     UP11/09/22 P F109

• R700 PSY UK71883

     UP11/09/22 P F109

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.