PM82032: DFHZC0001 ABEND 0C4 AKEA OFFSET 2CBA INTO DFHZGRP AFTER A VTAM FAILURE

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• You are running CICS TS 4.1 and VTAM goes down.
  
  You receive the following messages:
  
  DFHZC3443  VTAM has been cancelled or the ACB has been
              forceclosed . VTAM sessions terminated.
  DFHZC2316  VTAM ACB is closed
  DFHZC0200  An attempt by the COVR transaction to OPEN VTAM
  has failed with return code X'0000005C'; CICS will retry.
  DFHZC0001  An abend (code 0C4/AKEA) has  occurred at
             offset X'2CBA' in module DFHZGRP.
    .
   The failing instruction was a move character- MVC
   D25A B000 E000
   Register RB contained zeros causing the ABEND0C4.
   RB was loaded from the TCTTE+23C or field TCTE_PRSS_CV29_PTR.
   The CICS internal trace showed this field was getmained
   by the COVR transaction from shared storage remark PRSSCV29.
     But there was a task still associated with this particular
   terminal that was not cleaned up yet when VTAM went away.
   It freemained this storage- TCTE_PRSS_CV29_PTR, causing
   the field to contain zeros. Later when the COVR task tried
   to restore this terminal, it received the 0C4 abend when
   referencing this field.
  
  
  Additional Symptom(s) Search Keyword(s): KIXREVSCB
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICS users.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: DFHZC0001 ABEND0C4 AKEA in module       *
  *                      DFHZGRP after a VTAM failure.           *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  A transaction started at a terminal, for example, TERM, on the
  TOR is routed to the AOR over an MRO connection. The task
  becomes suspended on IRLINK waiting for a reply from the AOR.
  While the task is suspended VTAM is  terminated.
  During VTAM shutdown, the CICS/TS VTAM TPEND exit DFHZTPX is
  driven, which schedules DFHZSHU to terminate all VTAM sessions
  to CICS. DFHZCLS is scheduled for CLSDST clean-up processing for
  all the VTAM sessions but does not run immediately for terminal
  TERM because it is still associated with a task.
  As VTAM Persistent Sessions support is enabled DFHZSHU ATTACHes
  transaction COVR which issues repeated EXEC CICS SET VTAM OPEN
  commands every 5 seconds. On the third attempt VTAM has been
  re-started and COVR successfully re-opens the CICS ACB resulting
  in a call to DFHZGRP for PRSS_INITIALISATION
  STARTUP_TYPE(VTAM_RESTART). DFHZGRP issues a GETMAIN for VTAM
  persistent session control vector 29, PRSSCV29, for each
  terminal to be recovered, including terminal TERM. DFHZGRP then
  issues a VTAM OPNDST OPTCD=RESTORE call before suspending on
  resource_name ('PSOP1ECB') resource_type ('ZC_ZGRP ') to await
  completion of the OPNDST.
  Whilst the OPNDST RESTORE is being processed the transaction
  that was routed from terminal TERM is resumed and terminates,
  allowing DFHZCLS to run for CLSDST of terminal TERM. During
  DFHZCLS clean-up the PRSSCV29 storage is FREEMAINed.
  The OPNDST RESTORE completes ok and DFHZGRP attempts to copy the
  PRSSCV29 data to storage at tcte_prss_cv29_ptr. However the
  PRSSCV29 data for terminal TERM has been freed resulting in the
  reported message.
  DFHZC0001 An ABEND (code 0C4/AKEA) has occurred in module
  DFHZGRP.
  
  Additional keywords: MSGDFHZC3443 MSGDFHZC2316 MSGDFHZC0200
                      MSGDFHZC0001 MSGDFHME0116 MSGDFHZC2316
                      TCTE_NIB_TCTTE_MATCHED    PSOP1ECB
                      ZC_ZGRP TCTE_PRSS_CV29_PTR PM38706 PM45506
  

Problem conclusion

• DFHZGRP has been changed to check if the session to be restored
  is scheduled for CLSDST, and if so it is unbound instead.
  

Temporary fix

• FIX AVAILABLE BY PTF ONLY
  

Comments

APAR Information

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

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

  PM85283 PM85286 UK93327 UK93328

Modules/Macros

•    DFHZGRP
  

Fix information

• Fixed component name

  CICS TS Z/OS V4

• Fixed component ID

  5655S9700

Applicable component levels

• R600 PSY UK93327

     UP13/04/20 P F304

• R700 PSY UK93328

     UP13/04/20 P F304

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.