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PI77676: CPSM CMAS INCORRECTLY UPDATES MASDIR RECORD RESULTING IN SUBSEQUENT CONNECT FAILURE

A fix is available

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APAR status

  • Closed as program error.

Error description

  • An issue exists where a CMAS may incorrectly update a MASDIR
    record for the active CICSPLEX. When that occurs, the CMAS is
    subsequently unable to send anything down to the MAS during a
    CONNECT, so a MAS will hang during its connect process, until
    the MASINITTIME time expires. When that occurs, the CMAS EYULOG
    will have a message similar to the following:
    .
    EYUTS0021E CMAS0001 Topology Connect of CICS System MAS00001
                        failed due to a Resource Topology
                        Collection Time-Out.
    EYUTS0002E CMAS0001 Topology Connect for MAS00001 Failed -
                        APPLID(MAS00001) CICSplex(PLEX0001).
    .
    .
    Formatting the trace using  VERBX EYU9D### 'TRC=A,JOB=cmasname'
     you will see exception traces similar to the following:
    .
    Task  Mtd  Prev Tran Obj Level Pt-ID  Debug
    12345 TSSC XLOP TSSC TOP Excp     14 NLGTTOUT
    12345 CTBP CAMM TSSC COM Excp     28 TrgtUnav
    12345 TSSC XLOP TSSC TOP Excp     20 TSSCCPUM
    .
    In the full trace, the MAL for the call to CTBP will show a
    status of SCOPE_NOT_FOUND
    .
    .
    Additional Symptom(s) Search Keyword(s): TSSC EXCEPTION
    METHOD_FAILED TISTTSSC CAMMCTBP
    KIXREVSCB
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED: All CICSPlex SM V5R1M0, V5R2M0 and V5R3M0    *
    *                 Users                                        *
    ****************************************************************
    * PROBLEM DESCRIPTION: Communications related problems can     *
    *                      occur when CMASes exchange network      *
    *                      topology information:                   *
    *                                                              *
    *                      -  The communications control block for *
    *                         a MAS (MASDIR) may be updated        *
    *                         invalidly.  This can result in       *
    *                         requests that should be sent to the  *
    *                         MAS to be lost, resulting in time    *
    *                         outs.                                *
    *                                                              *
    *                         If the MASDIR is updated while the   *
    *                         MAS is connecting to its CMAS, then  *
    *                         the connect may fail with variations *
    *                         of the following error messages:     *
    *                                                              *
    *                           EYUTS0021E Topology Connect of     *
    *                                      CICS System <masname>   *
    *                                      failed due to a         *
    *                                      <Resource Topology      *
    *                                      Collection | MAS        *
    *                                      Resource Installation>  *
    *                                      Time-Out.               *
    *                                                              *
    *                           EYUTS0002E Topology Connect for    *
    *                                      <masname> Failed -      *
    *                                      APPLID(<applid>)        *
    *                                      CICSplex(<plexname>).   *
    *                                                              *
    *                      -  MASes connected to a CMAS may not    *
    *                         join to other active CMASes that     *
    *                         manage the CICSplex the MAS is       *
    *                         associated with, or a CMAS may       *
    *                         attempt to join a MAS that is not    *
    *                         active or to which it is already     *
    *                         connected or joined.                 *
    ****************************************************************
    * RECOMMENDATION: After applying the PTF that resolves this    *
    *                 APAR, all CMASes must be restarted.  Note    *
    *                 that the restarts do not need to occur at    *
    *                 the same time.                               *
    ****************************************************************
    When CMASes connect directly or indirectly, they may exchange
    information about their view of the network at the time of the
    connect, including what CICSplexes, CMASes and MASes are active.
    This information usually is routed to all CMASes in the network.
    It is possible that during this information interchange, a CMAS
    will receive some of the information more than once, and for old
    data to be included in the interchange.
    
    Two possible problems that can occur during this interchange
    regarding active MASes have been identified:
    
    -  When information about a MAS is received through this
       interchange, method EYU0CPTI (CPTI) determines whether the
       request is an ADD, UPDATE or DELETE request, and passes that
       information on to method EYU0CPMI (CPMI):
    
       -  if the request is an ADD, CPMI will call method
          EYU0CPAM (CPAM), which will use the provided information
          to build a MASDIR for the MAS.
    
       -  if the request is an UPDATE, CPMI will call method
          EYU0CPUM (CPUM), which will use the provided information
          to update the existing MASDIR for the MAS.
    
       -  if the request is an DELETE, CPMI will call method
          EYU0CPDM (CPDM), which will use the provided information
          to delete the existing MASDIR for the MAS.
    
       The parameter list that CPTI sends to CPMI for an ADD can be
       corrupted, such that it indicates to CPMI that if the CPAM
       call indicates that it did not create a MASDIR because one
       already exists, that CPMI can then call CPUM to update the
       existing MASDIR.  If this occurs and the data that is used to
       update the MASDIR is stale data, including the information
       that this MAS is connected to a different CMAS, then
       subsequent communications requests to the MAS will be
       directed to the other CMAS, where they will be lost.  This
       can result in the problems documented above.
    
    -  If the MAS information received for an ADD indicates the the
       MAS is connected to another CMAS, then CPAM will build an
       EENDJOIN resource table.  This will be delivered to method
       EYU0CPLT (CPLT), which will then check if the EENDJOIN record
       was built from stale data.  It does this by validating that
       the time the MAS connected to its CMAS is later than the time
       its CMAS started.
    
       -  If CPLT determines that the EENDJOIN request is valid,
          then it passes the request onto the Topology component,
          which will initiate a Topology Join request for the MAS.
    
       -  If CPLT determines that the EENDJOIN request is not valid,
          then it calls CPDM to delete the MASDIR that was created
          by CPAM.
    
       A logic error in CPLT can result in the wrong CMAS's start
       time being compared to the MAS connect time.  This can result
       in the problems documented above.
    

Problem conclusion

  • To address these problems:
    
    -  CPTI has been updated to ensure it does not corrupt the
       parameter list it passes to CPMI for an ADD MAS request.
    
    -  CPLT has been updated to ensure its uses the start time for
       the CMAS that the MAS is connected to.
    

Temporary fix

Comments

APAR Information

  • APAR number

    PI77676

  • Reported component name

    CICS TS Z/OS V5

  • Reported component ID

    5655Y0400

  • Reported release

    90M

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    YesHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2017-03-06

  • Closed date

    2017-03-24

  • 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:

    PI77829 UI45858 UI45859 UI45860

Modules/Macros

  • EYU0CPLT EYU0CPTI
    

Fix information

  • Fixed component name

    CICS TS Z/OS V5

  • Fixed component ID

    5655Y0400

Applicable component levels

  • R00M PSY UI45860

       UP17/03/28 P F703 ¢

  • R80M PSY UI45858

       UP17/03/28 P F703 ¢

  • R90M PSY UI45859

       UP17/03/28 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.



Document information

More support for: CICS Transaction Server

Software version: 5.2

Reference #: PI77676

Modified date: 03 April 2017