PK31655: RECEIVING DFHZC3496 DUMP WHEN PERFORMED Z NET,CANCEL ON VTAM

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• You received several CICS dumps when you performed a z
  net,cancelon VTAM:
  DFHDU0201  CICSFR   ABOUT TO TAKE SDUMP. DUMPCODE: ZC3496  ,
  DUMPID: 210/0013
  DFHZC0134I CICSFR 369
  VTAM sessions persisted when OPEN ACB issued. Inquires issued 2,
  sessions persisting 28, sessions terminated 0, sessions OPNDSTed
  14, sessions in error 14
  
  From VTAM perspective, see the following sequence of events in
  the VIT:
  
  1) Open ACB (CICSFR)
  2) RVM is started
  3) SETLOGON PERSIST
  4) INQUIRE COUNTS
  5) INQUIRE PERSESS - 14 NIBs are returned and rc/fb is x'000D'
  6) OPNDST RESTORE - 14 NIBs are given - rc/fb is x'0000
  7) INQUIRE PERSESS - rc/fb is x'0007' - no NIBs returned
  8) OPNDST RESTORE - 14 NIBs are given - rc/fb is x'0009'
  The way VTAM behaves in this sequence of events
  is proper.  When the first INQUIRE PERSESS (step 5)
  is completed, RVM is not quite complete, so
  the command is posted with x'000D' as a return code/
  feedback pair, which indicates that there may be
  more sessions to inquire about.  Then the OPNDST
  RESTORE (step 6) restores those 14 sessions.
  At this point, CICS issues INQUIRE PERSESS
  again (step 7) and is posted with x'0007' return code,
  which indicates there is no information available
  to satisfy the request.  CICS should have
  stopped any attempts at recovery once this happened;
  instead, CICS passed another 14 NIBs to VTAM
  with another OPNDST RESTORE (step 8).  Since
  there are no sessions to restore, this request
  is posted with x'0009'.
  CICS should not issue the OPNDST
  RESTORE once the INQUIRE PERSESS is posted
  with x'0007'.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All.                                         *
  ****************************************************************
  * PROBLEM DESCRIPTION: Message DFHZC3496 with a system dump    *
  *                      after LU62 persistent session recovery  *
  *                      following a VTAM restart.               *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  VTAM is cancelled with a Z NET,CANCEL while CICS remains active.
  When VTAM is restarted LU62 persistent sessions between two CICS
  regions are recovered. Module DFHZGRP runs on CICS and issues an
  INQUIRE PERSESS request to VTAM to find out how many sessions
  are to be recovered. The INQUIRE returns OK with 14 NIBs rc/fb
  of x'000D' meaning there may be more sessions to recover.
  DFHZGRP issues OPNDST RESTORE for the 14 NIBs returned
  from the INQUIRE which completes successfully.
  DFHZXPS processing is scheduled for post restore processing but
  does not run immediately.
  As there may be more sessions to recover DFHZGRP issues a
  further INQUIRE PERSESS which returns rc/fb of x'0007', no
  further NIBS require recovery. However DFHZGRP processing
  continues as if the INQUIRE had returned some NIBs and again
  issues OPNDST RESTORE requests to VTAM using the residual
  information from the NIBLIST passed on the original request.
  The duplicate OPNDST RESTORE requests fail with rc/fb of x'0009'
  as the sessions have already been recovered. DFHZGRP schedules
  message DFHZC0131 for all the failing sessions and sets the
  recovery byte tcte_prss to tcte_no_prss_recovery.
  DFHZXPS runs expecting OPNDST restore processing to have been
  completed successfully. However the duplicate OPNDST RESTORE
  requests failed leaving the TCTTE is an inconsistent state.
  Specifically the tcte_prss recovery byte is
  tcte_no_prss_recovery which is only valid when
  tcte_prss_rej_attach is also set, which it is not.
  DFHZXPS schedules message DFHZC0155 for which one of the actions
  is ABEND TASK. Since there is no task message DFHZC3496 is
  issued with a system dump.
  
  Additonal keywords: PSTYPE MNPS MSGDFHZC0131 MSGDFHZC0155
                      MSGDFHZC3496
  

Problem conclusion

• DFHZGRP has been changed to prevent OPNDST RESTORE processing
  being done twice for the same NIBLIST.
  

Temporary fix

• FIX AVAILABLE BY PTF ONLY
  

Comments

APAR Information

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

  PK23647

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

  UK19600

Modules/Macros

•    DFHZGRP
  

Fix information

• Fixed component name

  CICSTS 3.1 Z/OS

• Fixed component ID

  5655M1500

Applicable component levels

• R400 PSY UK19600

     UP06/11/16 P F611

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.