PK96194: ABENDATCG DFHAP0002 DFHRM0002 ABENDU1800 BRINGS CICS DOWN

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• A task running on an session TCTTE gets an abend.
  RESTART is specified so DFHREST tries to restart the task.
    Other work wants to be processed on that session.
  The RESTART interacts with new work.
  The new task fails with abendATCG, followed by:
  DFHAP0002  A SEVERE ERROR (CODE X'0D99')
          HAS OCCURRED IN MODULE DFHCR1U.
  DFHRM0002  A SEVERE ERROR (CODE X'0377')
          HAS OCCURRED IN MODULE DFHRMLSO
  .
  In this case, the customer was connected via LU61 to IMS.
  They also got these messages:
  DFHDB8122I CICS IS ABOUT TO DISCONNECT FROM DBCTL
          FOR CICS SHUTDOWN.
  DFHDB8123I CICS DISCONNECTION FROM DBCTL FOR CICS SHUTDOWN
          HAS COMPLETED SUCCESSFULLY
  .
  At this point CICS comes down with:
  IEF450I    CICSBX2 - ABEND=S000 U1800 REASON=00000000
  .
  Additional keywords
  ABENDU1800 ATCG
  

Local fix

• Set RESTART to NO.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: ALL CICS users.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: If an LU6.1 backend transaction         *
  *                      defined as restartable abends, it       *
  *                      may cause CICS to abend U1800.          *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  A restartable transaction running in a region on the backend of
  an LU6.1 connection abends. That region then encounters message
  'DFHAP0002  A severe error (CODE X'0D99') has occurred in module
  DFHCR1U' followed by 'DFHRM0002  a severe error (CODE X'0377')
  has occurred in module DFHRMLSO'. Subsequently, the region
  abends U1800.
  The problem occurs because the logic to restart the backend task
  reattaches the backend transaction twice against the same
  terminal. Two calls are issued to DFHTFRF with a function of
  RELEASE_FACILITY, and each call causes a new task to be attached
  against the same terminal.
  
  Two exception traces are issued when one of the new
  backend tasks abends again.
  
  AP0D99 CR1U  *EXC* COMMIT INQUIRE_LINK FAILED -
                     FUNCTION(PERFORM_COMMIT)
  
  RM0377 RMLSO *EXC* Bad_response_from_client
  
  The TCTTE holds an invalid rmln_link_token for this task
  
  additional keywords:
  CR1U 0D99 AP0002 LU61 1800 ABENDU1800
  

Problem conclusion

• DFHCR1U has been amended to only reattach a restartable LU 6.1
  backend transaction once.
  

Temporary fix

•             *********
              * HIPER *
              *********
  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:

  PM01217 UK52934 UK52935

Modules/Macros

•    DESCR    DESCRUOW DFHCRBU  DFHCRD   DFHCRESI
  DFHCRIU  DFHCRL   DFHCRLB  DFHCRLBA DFHCRLBM DFHCRLBT DFHCR1U
  DFHCR2U
  

Fix information

• Fixed component name

  CICSTS V3 Z/OS

• Fixed component ID

  5655M1500

Applicable component levels

• R400 PSY UK52934

     UP09/12/21 P F912

• R500 PSY UK52935

     UP09/12/21 P F912

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.