IBM Support

PI82188: AFCZ ENCOUNTERED AFTER A READ OF CFDT FILE DUE TO TWO TASKS GIVING CFDT THE SAME UOWID WHICH LEAD TO MESSAGE DFHFC7130

A fix is available

Subscribe

You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • In the dump1 task AAAA had rmuw X'11111111' with UOWID
    X'A1A1A1A1A1A1A1A1' and was inflight. BBBB had rmuw X'22222222'
    with UOWID X'A1A1A1A1A1A1A1A1' and was indoubt within syncpoint
    at the time. Note the duplicated uowids. This is the underlying
    cause of the problem. This causes a AFCZ abend which eventually
    leads to a UOWID lock situation which is documented in message
    DFHFC7130.
    Later, the following message is issued:
    DFHAC2249 Transaction xxxx running program program term ???? has
              failed with abend ASP7 following the failure partner
              system UNKNOWN in the prepare phase of syncpoint.
              Updates will be backed out.
    .
    The failing task is issuing an EXEC CICS SYNCPOINT command,
    which is failing. The RM domain shows that DB2 voted NO.
    Looking at the CSUB for this task, which has the TRACE of
    calls to DB2, we see DB2 error code 00F30048 on the PREPare.
    Code 00F30048 means:
       An abend has occurred during an attempt to access the
       attachment-  provided 'Network ID' while executing in the
       caller's PSW key.
    Looking closer at tasks in CICS, we notice 2 tasks have the
    same UOWID, which should never happen:
    RM domain:
      UOW      UOW      Local UOW Id     Stat  Tran  Tran
      Address  Token                           Num   ID
      -----------------------------------------------------
      23A786A0 token1   D27B23134021D996 com   11111 aaaa
      23A386A0 token2   D27B23134021D996 infl  22222 bbbb
                        ****************
    Monintoring domain shows both these tasks have done more
    than 1 syncpoint command.
    Each time a syncpoint is issued, CICS assigns a new UOWID.
    In this release, this is done via a STCKF command, which
    can give identical values, Verses the STCK command which
    was previously used.
    An alternative symptom of the problem is message:
      DFHFC0002 CP1BPTB1 A severe error (code X'2468') has occurred
      in module DFHFCDR.
    followed by abends AFCV, AFCY, AFCI and then message:
        DFHFC7130 Unit of work X'xxxxxxxxxxxxxxxx' running in
                  region CP1BPTB1 in MVS system XXXX holds a lock
                  on key X'xxxxxxxxxxxxxxxx' in coupling facility
                  data table XXXXXXXX in pool XXXXXX, which caused
                  this request to wait.
    ADDITIONAL KEYWORDS: ABENDAFCV ABENDAFCY ABENDAFCI
                         msgDFHFC7130 msgDFHAC2249 msgDFHFC0002
                         DUPLICATE UOWID UOW ID ABEND0F4
    RSN66600329 , RSN66803004, RSN66803006 KIXREVACC
    Please note that this problem is not applicable to
    CICS 5.1 or CICS 5.2.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED: All CICS users                               *
    ****************************************************************
    * PROBLEM DESCRIPTION: CICS DB2 applications abend or          *
    *                      CICS CFDT records become locked         *
    *                      due to two CICS tasks passing           *
    *                      non-unique Unit Of Work IDs.            *
    ****************************************************************
    * RECOMMENDATION: .                                            *
    ****************************************************************
    Two or more CICS tasks obtain the same Unit Of Work ID (UOWID)
    and pass the ID to DB2 or CFDT.
    DB2 or CFDT fail with various problems because they think that
    they are being called out of sequence for just one unit of
    work.
    KEYWORDS: abend0f4 0f4 vsam
              lock
    

Problem conclusion

  • CICS RM Domain has been changed to use a STCK
    instruction to generate a UOWID.
    STCK is guaranteed to provide a unique 8 byte token.
    

Temporary fix

Comments

APAR Information

  • APAR number

    PI82188

  • Reported component name

    CICS TS Z/OS V5

  • Reported component ID

    5655Y0400

  • Reported release

    000

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    YesHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2017-05-25

  • Closed date

    2017-06-08

  • Last modified date

    2017-07-05

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

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

    UI47871 PI83316

Modules/Macros

  • DFHR2TRI DFHRMCD  DFHRMCD1 DFHRMCD2 DFHRMCI2 DFHRMCI3 DFHRMCI4
    DFHRMDM  DFHRMDU0 DFHRMDU2 DFHRMDU3 DFHRMDU4 DFHRMDU5 DFHRML1D
    DFHRMLK1 DFHRMLK2 DFHRMLK3 DFHRMLK4 DFHRMLK5 DFHRMLKQ DFHRMLN
    DFHRMLSD DFHRMLSF DFHRMLSO DFHRMLSP DFHRMLSS DFHRMLSU DFHRMNM
    DFHRMNM1 DFHRMNS1 DFHRMNS2 DFHRMOT  DFHRMR1D DFHRMR1E DFHRMR1K
    DFHRMR1S DFHRMRO  DFHRMRO1 DFHRMRO2 DFHRMRO3 DFHRMRO4 DFHRMROO
    DFHRMROS DFHRMROU DFHRMROV DFHRMRS  DFHRMST  DFHRMST1 DFHRMTRI
    DFHRMU1C DFHRMU1D DFHRMU1E DFHRMU1F DFHRMU1G DFHRMU1J DFHRMU1K
    DFHRMU1L DFHRMU1N DFHRMU1Q DFHRMU1R DFHRMU1S DFHRMU1U DFHRMU1V
    DFHRMU1W DFHRMUC  DFHRMUO  DFHRMUW  DFHRMUW0 DFHRMUW1 DFHRMUW2
    DFHRMUW3 DFHRMUWB DFHRMUWE DFHRMUWF DFHRMUWH DFHRMUWJ DFHRMUWL
    DFHRMUWN DFHRMUWP DFHRMUWQ DFHRMUWS DFHRMUWU DFHRMUWV DFHRMUWW
    

Fix information

  • Fixed component name

    CICS TS Z/OS V5

  • Fixed component ID

    5655Y0400

Applicable component levels

  • R000 PSY UI47871

       UP17/06/16 P F706 ¢

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.



Document information

More support for: CICS Transaction Server

Software version: 5.3

Reference #: PI82188

Modified date: 05 July 2017


Translate this page: