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PI19853: DFHPC0409 ' ABENDS AD3K AND AEXZ WHILE PROCESSING AEXZ ' WHEN AN OPENAPI PROGRAM GETS AICA'D OUT OF A LOOP.

A fix is available

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APAR status

  • Closed as program error.

Error description

  • Your CICS region abends with the following message:
    .
    DFHPC0409 DBDCCICS Abends AD3K and AEXZ have been issued while
    processing abend AEXZ for the same task, transaction TRN1.
    .
    This happens for a transaction that has been initiated as a Web
    Service, has made SQL calls, and has an OPENAPI program that
    loops solidly until ICVR processing initiates an abendAICA .
    .
    In the PC0409 dump, here are the kernel error entries
    pertaining to this transaction:
    .
    KE_NUM  ERROR TYPE           ERR_CODE  MODULE    OFFSET
    ======  ==========           ========  ======    ======
     0031   ABEND                ---/0999  -noheda-  0002C27C
     0031   TRAN_ABEND_PERCOLATE ---/AICA  DFHSR1    00000778
     0031   TRAN_ABEND_PERCOLATE ---/AEXZ  DFHPCP    00000696
     0031   TRAN_ABEND_PERCOLATE ---/AEXZ  DFHEPC    00001CD0
     0031   TRAN_ABEND_PERCOLATE ---/AEXZ  DFHEPC    00000226
     0031   ABEND                04E/AKEB  UNKNOWN   UNKNOWN
     0031   TRAN_ABEND_PERCOLATE ---/AD3K  DFHPCP    00000696
     0031   TRAN_ABEND_PERCOLATE ---/AD3K  DFHD2EX1  00000D64
     0031   TRAN_ABEND_PERCOLATE ---/AD3K  DFHERM    0000150A
     0031   TRAN_ABEND_PERCOLATE ---/AD3K  DFHERMSP  00000EEC
    .
    The 0999 and AICA happen because an OPENAPI program was in
    non-yielding loop for more CPU time than is specified in ICVR.
    This leaves the transaction's L8 TCB unusable.
    .
    The next group of 3 AEXZs happens when trying to return to the
    program that called (via EXEC CICS LINK) the looping program.
    That calling program is also OPENAPI so DFHEPC wants to
    change_mode back to the L8 TCB.  That fails because the L8 is
    unusable and that causes DFHEPC to initiate the abendAEXY.
    .
    Control percolates to DFHPITP which is the CICS Web Service
    program that invoked the target application program.  DFHPITP
    initiates a syncpoint rollback.  That involves talking with DB2
    which needs to happen on the L8 which is unusable.  So the
    talking to DB2 happens on the QR which is the cause of the
    04E/AKEB and the AD3Ks.  That abend percolates back to DFHPITP
    where it does an EXEC CICS SOAPFAULT CREATE.  That works fine
    until DFHEIP wants to return to DFHPITP (which is also defined
    OPENAPI) and change_mode to the L8.  That fails and initiates
    the final AEXZ that causes the DFHPC0409 .
    .
    
    Additional Symptom(s) Search Keyword(s): KIXREVDWZ
    

Local fix

  • If you can not prevent the loop in the OPENAPI program, define
    that program as QUASIRENT.
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED: All CICS users.                              *
    ****************************************************************
    * PROBLEM DESCRIPTION: CICS issues message DFHPC0409 after an  *
    *                      AICA abend on an open TCB.              *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    CICS is acting as a web service provider. The CICS web service
    pipeline runs under an L8 TCB. The web service target program
    links to other threadsafe openapi programs, which issue DB2
    requests. One of these programs enters a loop, which is
    trapped with an abend AICA.
    .
    The program running at the time of the abend was defined to be
    CONCURRENCY(THREADSAFE), API(OPENAPI). The L8 TCB is therefore
    marked unclean, and can no longer be used.
    During the course of recovering from the AICA, a number of other
    abends are issued including AEXZ abends brought about by
    attempting to switch back to the L8 TCB. There is also an AD3K
    abend, during the attempt to dissociate from DB2. This is
    because the L8 TCB is unavailable, and this is now driven under
    the QR TCB.
    .
    CICS now appears to be in a recursive abend loop, and is
    terminated with message DFHPC0409.
    .
    Additional keywords: abendAICA abendAD3K abendAEXZ
                         PC0409 msgDFHPC0409
    

Problem conclusion

  • DFHEIP and DFHEPC have been updated to avoid the AEXZ abend if
    the required TCB is no longer available.
    DFHPITL has been updated to ensure that CICS changes to the
    QR TCB if the original open TCB is no longer available.
    

Temporary fix

  •             *********
                * HIPER *
                *********
    FIX AVAILABLE BY PTF ONLY
    

Comments

APAR Information

  • APAR number

    PI19853

  • Reported component name

    CICS TS Z/OS V4

  • Reported component ID

    5655S9700

  • Reported release

    700

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    YesHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2014-06-11

  • Closed date

    2014-09-30

  • Last modified date

    2014-11-04

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

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

    PI24959 UI21927

Modules/Macros

  • DFHEIP   DFHEPC   DFHPITL
    

Fix information

  • Fixed component name

    CICS TS Z/OS V4

  • Fixed component ID

    5655S9700

Applicable component levels

  • R700 PSY UI21927

       UP14/10/08 P F410 ½

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.

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Document Information

Modified date:
04 November 2014