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PI88227: EXEC CICS READ AGAINST FILE1 SUCCESSFULLY READS A RECORD FROM FILE2 WHEN USING SHARED DATA TABLES AND FOR IS RECYCLED.

A fix is available

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APAR status

  • Closed as program error.

Error description

  • A CICS application program successfully does an EXEC CICS READ
    against FILE1.  But the record returned is a record from a
    different file (FILE2).  This happens intermittently in the
    following situation:
    .
    1) Both files are Shared Data Tables owned by a FOR.  (The FOR
    is the CICS Region that opens the file.)
    .
    2) Both files are accessed by applications running in an AOR.
    .
    3) The FOR is brought down and restarted while the AORs remain
    active.
    .
    4) After the FOR is restarted, applications in the AORs
    sometimes get the problem.
    Additional Symptom(s) Search Keyword(s): KIXREVxxx
    

Local fix

  • Restart all AORs when the FOR is recycled.
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED: All CICS users of remote shared data tables. *
    ****************************************************************
    * PROBLEM DESCRIPTION: When a File Owning Region (FOR) is      *
    *                      restarted, file control requests from   *
    *                      the  active Application Owning Region   *
    *                      (AOR) can return records from the wrong *
    *                      file.                                   *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    There are two connected CICS systems. A File Owning Region (FOR)
    that contains locally defined shared data table (SDT) files and
    an Application Owning Region (AOR) that contains remote
    definitions to those SDT files. The AOR has connected to the
    remote SDT files and issued some file control (FC) requests
    against them. The FOR is now shutdown and restarted. The SDT
    files are reopened. When the SDT files are reopened the files
    use the same data table token and vector position as used in the
    previous run of the FOR. However, the token and vector pairs are
    allocated to different files from the last run.
    
    The AOR continues to issue file control requests against the
    remote SDT files. The first file control request that leads to
    an open will reconnect the two CICS regions and receive the
    correct record back. Prior to an open request all file control
    requests against previously opened remote SDTs will have been
    shipped to the AOR. After the first open and the reconnect
    (ETCON) of the two CICS systems, all following file control
    requests will use the data table token and vector pair to access
    the shared area and as the file allocated to that pair has now
    changed the wrong record will be received.
    

Problem conclusion

  • DFHDTSVS and DFHDTRC have been altered so that when an ETCON is
    issued during a successful CONNECT this information is passed
    back to File Control. DFHFCFR, DFHFCFS and DFHFCDTS have been
    altered so that upon detecting that the FOR has been restarted
    that a close file request is made against all remote SDT files
    that have already been connected. This means that upon the first
    file control request made against those closed and disconnected
    files, we will immediately enter SDT processing and issue a
    clean reconnect rather than shipping the request or receiving
    the incorrect record.
    
    CICS Transaction Server for VSE/ESA, CICS Data Areas, Release 1,
    LY33-6086-01 has been altered in Section FCS, File Control
    Static Storage. The General data table fields have been updated
    to add in new bit FC_DT_RECONNECT_ISSUED. The table will look as
    follows:-
    ________________________________________________________________
             General data table fields
    ________________________________________________________________
    (168) CHARACTER    8  FC_DT_LAST_INIT    Time of last attempt to
                                             issue AOR DTP_INIT
    (168) UNSIGNED     4  FC_DT_LH_
                          LAST_INIT
                                             Left half of clock
    (170) ADDRESS      4  FC_DT_2            Entry point for data
                                             tables initialization
    (174) ADDRESS      4  FC_DT_CLOSE_       Files to be closed
                          CHAIN
    (178) BITSTRING    1  FC_DT_CLOSE_ECB    Files to be closed ECB
    (179) BITSTRING    1  *                  FOR support indicators
           1...  ....      FC_DT_FOR_
                           NOSHARING
                                             FOR cannot support SDT
           .1..  ....      FC_DT_FOR_
                           LOGGED_ON
                                             FOR logged on
           ..1.  ....      FC_DT_FOR_        FOR not authorized
                           NOTAUTH
           ...1  1111      *                 Reserved
    (17A) BITSTRING    1  *                  AOR support indicators
           1...  ....      FC_DT_AOR_
                           NOSHARING
                                             AOR cannot use SDT
           .1..  ....      FC_DT_RECONNECT_
                           ISSUED
                                             AOR issued ETCON
           ..11  1111      *                 Reserved
    (17B) BITSTRING    1  *                  Reserved
    ________________________________________________________________
    
    CICS Transaction Server for VSE/ESA, Shared Data Tables Guide,
    Release 1 (SC33-1668-00), Chapter 5. Application programming for
    shared data tables, section Using cross-memory services,
    subsection Disconnection on page 30 - 31 needs to have the
    following paragraphs added to it.
    
    When the FOR restarts, it issues a series of actions on the open
    file. During the shutdown phase, the FOR closes the file, and
    disconnection is scheduled at the next non-update request that
    is issued for that file. During the restart phase, if the file
    is installed, opened, and enabled before the AOR issues the next
    non-update request, this request triggers the closing of all
    open remote shared data table files. A disconnection request to
    ensure data integrity is also issued. These files issue open and
    connection actions upon the next non-update request.
    
    If any files have outstanding browse requests, the close becomes
    pending and the disconnect does not occur. There is a risk of
    reading back the wrong record until the browse request is
    completed and has triggered the completion of the close request
    and disconnection. It is recommended to restart the AOR when
    restarting the FOR, to ensure data integrity of the shared data
    table files.
    

Temporary fix

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

Comments

APAR Information

  • APAR number

    PI88227

  • Reported component name

    CICSTS FOR VSE

  • Reported component ID

    564805400

  • Reported release

    B0P

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    YesHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2017-10-02

  • Closed date

    2018-04-24

  • Last modified date

    2018-05-07

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

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

    PI89960 UI55410

Modules/Macros

  • DFHDTPDS DFHDTRC  DFHDTSVC DFHFCDTS DFHFCFR  DFHFCFS  DFHFCSDS
    

Publications Referenced
LY33608601SC33166800   

Fix information

  • Fixed component name

    CICSTS FOR VSE

  • Fixed component ID

    564805400

Applicable component levels

  • RB0P PSY UI55410

       UP18/05/07 I 1000 ¢

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:
07 May 2018