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

Obtain the fix for this APAR.

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 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
  

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.