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OA51945: AFTER IFCC ON IXLLOCK, IXLSYNCH OR IXLRT REQUEST CREATING RECORDDATA, RECORD DATA ENTRY CREATED ON WRONG L 17/01/19 PTF PECHANGE

A fix is available

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APAR status

  • Closed as program error.

Error description

  • IXLLOCK, IXLSYNCH or IXLRT requests which causes creation of a
    new record data entry against a lock structure may
    cause the record data entry to be created on the
    wrong list. This may occur after the initial operation for the
    write request to the coupling facility encounters an IFCC.
    
    This may prevent IXLRT processing from correctly reporting,
    deleting or updating record data entries created by a connector.
    
    This is only a problem with z/OS 2.2 with Apar OA47796
    (NEW FUNCTION - SUPPORT FOR SYSTEM-MANAGED ASYNCHRONOUS
    DUPLEXING FOR LOCK STRUCTURES) installed.
    
    Known Symptoms:
    IXLRT Request=ReadByConn processing may incorrectly
    complete with RC=8 (IxlRetCodeParmError), RSN=xxxx0887
    (IxlRsnCodeBadExtResToken).
    
    IXLRT Request=ReadAll processing may incorrectly show
    record data created by one connector, owned by another
    connector (via MrtdOwnerConId).
    
    IXLRT Request=DeleteByConn processing may delete record
    data created by a different connector that was placed
    on an incorrect list.
    
    IXLRT Request=READ|DELETE|UPDATE with VERCONNAME may
    fail unexpectedly with RC=8 (IxlRetCodeParmError),
    RSN=xxxx080B (IxlRsnCodeBadConName)
    
    PE Information:
    
    Users Affected:
    Users with APAR: OA47796 PTF: UA82981 (HBB77A0) installed
    supporting connectors to lock structures with record data.
    
    APAR OA47796: New Function - Support for system-managed
    asynchronous duplexing for lock structures
    
    New function APAR that introduced an asynchronous
    system-managed duplexing protocol for improved duplexing
    performance.
    
    User Impact:
    
    APAR OA47796 fixed the original problem but it
    introduced a new problem.
    
    The orginal APAR introduced new function available to
    connectors to lock structures that provides an
    asynchronous system-managed duplexing protocol to help
    improve duplexing performance. However, it may regress
    function for connectors to lock structures with record
    data. Including those not exploiting asynchronous
    system-managed duplexing.
    
    After encountering an IFCC on an IXLLOCK, IXLSYNCH or IXLRT
    request creating record data, the record data entry may be
    created on a wrong list of the structure in the coupling
    facility. This may prevent IXLRT processing from correctly
    reporting, deleting or updating record data entries created
    by a connector including:
    
      IXLRT Request=ReadByConn processing may incorrectly
      complete with RC=8 (IxlRetCodeParmError), RSN=xxxx0887
      (IxlRsnCodeBadExtResToken).
    
      IXLRT Request=ReadAll processing may incorrectly show
      record data created by one connector, owned by another
      connector (via MrtdOwnerConId).
    
      IXLRT Request=DeleteByConn processing may delete record
      data created by a different connector that was placed
      on an incorrect list.
    
      IXLRT Request=READ|DELETE|UPDATE with VERCONNAME may
      fail unexpectedly with RC=8 (IxlRetCodeParmError),
      RSN=xxxx080B (IxlRsnCodeBadConName)
    

Local fix

  • Remove or do not apply the fix for OA47796, or apply the
    ++APAR for OA51945 when available.
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED: Users of z/OS V2R2 (HBB77A0) who are running *
    *                 in a Parallel Sysplex environment making use *
    *                 of coupling facility lock structures with    *
    *                 record data for sysplex-scope serialization  *
    *                 functions. In particular those with APAR     *
    *                 OA47796 installed.                           *
    ****************************************************************
    * PROBLEM DESCRIPTION: Due to programming errors:              *
    *                                                              *
    *                      1.  With support provided by APAR       *
    *                      OA47796 (New function SPE providing     *
    *                      support for system-managed asynchronous *
    *                      duplexing for lock structures),         *
    *                      encountering an IFCC during IXLLOCK,    *
    *                      IXLSYNCH or IXLRT request processing    *
    *                      that creates record data, the record    *
    *                      data can be created on the wrong list   *
    *                      of the structure in the coupling        *
    *                      facility. This may prevent IXLRT        *
    *                      processing from correctly reporting,    *
    *                      deleting or updating record data        *
    *                      entries created by a connector.         *
    *                                                              *
    *                      2. IXLLOCK alter requests changing the  *
    *                      state from shared to exclusive and      *
    *                      encountering an IFCC may incorrectly    *
    *                      begin global management of the          *
    *                      resource.                               *
    *                                                              *
    *                      These errors may be encountered when    *
    *                      the structure is not asynchronously     *
    *                      duplexed.                               *
    *                                                              *
    *                      SYSPLEXDS                               *
    ****************************************************************
    * RECOMMENDATION: PTFs should be applied to all systems in the *
    *                 sysplex via rolling ipl.                     *
    ****************************************************************
    Due to a programming error introduced with support provided by
    APAR OA47796 IXLLOCK, IXLSYNCH or IXLRT requests that create
    record data may create the record data on the wrong list of the
    lock structure.  This can occur after the initial operation for
    the request to create the record data in the coupling facility
    encounters an IFCC and the processing is subsequently internally
    redriven.  When redriven, the wrong list is selected for the
    redriven request.
    
    Creating the record data on the wrong list may prevent IXLRT
    processing from correctly reporting, deleting or updating record
    data entries created by a connector including:
    
    - IXLRT Request=ReadByConn processing that may incorrectly
      complete with RC=8 (IxlRetCodeParmError), RSN=xxxx0887
      (IxlRsnCodeBadExtResToken).
    
    - IXLRT Request=ReadAll processing that may incorrectly show
      record data created by one connector, owned by another
      connector (via MrtdOwnerConId).
    
    - IXLRT Request=DeleteByConn processing that may delete record
      data created by a different connector that was placed on an
      incorrect list.
    
    - IXLRT Request=READ|DELETE|UPDATE with VERCONNAME processing
      that may fail unexpectedly with RC=8 (IxlRetCodeParmError),
      RSN=xxxx080B (IxlRsnCodeBadConName)
    
    Due to a programming error with IXLLOCK alter processing,
    requests changing the state for a resource being locally managed
    from shared to exclusive and being internally redriven (e.g.
    after encountering an IFCC) may incorrectly cause global
    management to be entered.  This results in unnecessary
    processing for entering and ending global management of the
    resource.  For MODE=SYNCEXIT requests, this will also cause the
    CmplReqHadContention indication to be incorrectly reported to
    the completion exit in the Completion Exit Parameter List
    (CMPL).
    

Problem conclusion

  • Modifications made to correct the program errors:
    
    1. The correct record data list is now selected for creating
    the record data entry on the internally redriven flow for
    IXLLOCK, IXLSYNCH or IXLRT requests creating record data that
    encounter an IFCC during processing.
    
    2. IXLLOCK requests altering resources being locally managed
    from shared to exclusive and being internally redriven (e.g. due
    to an IFCC) will no longer incorrectly begin global management
    for the resource, or cause the CmplReqHadContention indication
    to be incorrectly reported to the completion exit in the CMPL.
    

Temporary fix

  • *********
    * HIPER *
    *********
    

Comments

APAR Information

  • APAR number

    OA51945

  • Reported component name

    CROSS SYS.EXT.S

  • Reported component ID

    5752SCIXL

  • Reported release

    7A0

  • Status

    CLOSED PER

  • PE

    YesPE

  • HIPER

    YesHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2017-01-19

  • Closed date

    2017-03-16

  • Last modified date

    2017-04-03

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

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

    UA91355

Modules/Macros

  • IXLR1ALR IXLR1GRT IXLR1LKR IXLR1RT  IXLR1SYN IXLR1UNL
    

Fix information

  • Fixed component name

    CROSS SYS.EXT.S

  • Fixed component ID

    5752SCIXL

Applicable component levels

  • R7A0 PSY UA91355

       UP17/03/29 P F703 ­

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:
03 April 2017