II14405: DB2 HANGS, THREAD HANGS DUE TO VTAM HANG

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You can track all active APARs for this component.

APAR status

  • Closed as canceled.

Error description

  • 5740XYR00 DB2DDF DB2SNA
    Defects: 00193_228_631 d00193_228_631
               00276_228_631 d00276_228_631
               17368_004_000 d17368_004_000
               57296_228_631 d57296_228_631
    The purpose of this Informational APAR is to help DB2 L2
    identify a hang condition in the DB2 distributed environment
    that can be caused by the VTAM error described by APAR OA23264.
    If this APAR is not installed, it should be installed as soon
    as possible because the error can result in many unpredictable
    symptoms, typically hangs, that are difficult to diagnose.  It
    is important that this APAR be installed on any z/OS system,
    local or remote, that may be involved.
    .
    Some external symptoms include:
    DB2 applications hang, DB2 threads hang, and some customer
    reported SQLCODE -904 returned to their applications.  Some
    customers have pointed out that the VTAM (SNA) communication
    between two DB2 subsystems hang.  Some customers may say that
    their DB2 appears hung.
    .
    The ultimate cause is that a DB2 thread, typically a DB2 system
    related thread, will hang indefinitely in a VTAM Deallocate
    call (DEALLOC ABNDUSER) after the DB2 thread incorrectly
    receives RCPRI/RCSEC (PRImary Return Code/SECondary Return Code)
    002C/0002 on a VTAM Receive.  So it's not only important to
    determine the DB2 thread that is hung in a VTAM deallocate call,
    but it's also important to determine what happened on the prior
    VTAM call (typically an Asynchronous Receive).  If the prior
    VTAM call resulted in an RCPRI/RCSEC 002C/0002, then the VTAM
    error described in APAR OA23264 may be the likely root cause.
    The DB2 LITR associated with the thread should identify the most
    recent activity.
    Look for evidence where a VTAM call, typically Async RECV,
    receives primary/secondary return code of 002C/0002
      RCPRI RPL6RCPR 002C RCPRI002C RPL6RCPR002C USF6PARM with
      RCSEC RPL6RCSC 0002 RCSEC0002 RPL6RCSC0002 USF6IVCI
    which is then followed by a VTAM DEALLOC ABNDUSER 08640000 that
    appears to hang indefinitely.
    .
    BYPASS:
    The problem can possibly be bypassed by recycling the REMOTE
    subsystem (the server subsystem), and/or by recycling DDF at
    the local subsystem.
    Issue the following commands in sequential order:
      -STOP DDF MODE(QUIESCE), wait 3 minutes
      -STOP DDF MODE(FORCE), wait 3 minutes for the operation to
       complete
      -START DDF
    Diagnostic information:
    The DB2 "DISPLAY LOCATION(*) DETAIL" and/or "DISPLAY THREAD(*)
    DETAIL" commands may help in identifying the multiple DB2 z/OS
    subsystems involved in the condition.  Console dumps should be
    obtained from all suspected DB2 subsystem environments.  Ensure
    that all DB2 address spaces, and the VTAM address space, are
    included in each console dump.
    For example:
      DUMP COMM=(ssnm DUMP)
      n,JOBNAME=(ssnmMSTR,ssnmDIST,ssnmDBM1,ssnmIRLM,VTAMxxxx),CONT
      n,SDATA=(RGN,CSA,LSQA,SQA,PSA,SWA,LPA,TRT,GRSQ,SUM,ALLNUC),END
      where ssnm is the DB2 subsystem name.
      .
      To ensure maxspace size is large enough, issue
        CD SET,SDUMP MAXSPACE 5000M
      and please also ensure the dump data set (SYS1.DUMPxx) is
    large enough.
    Please engage VTAM support to get instructions on the diagnostic
    information that may be required to diagnose the condition from
    a VTAM perspective.
    

Local fix

  • Recycle the REMOTE DB2 subsystem
    and/or
      Recycle DDF at the local subsystem
    

Problem summary

Problem conclusion

Temporary fix

Comments

  • Informational APAR
    

APAR Information

  • APAR number

    II14405

  • Reported component name

    PB LIB INFO ITE

  • Reported component ID

    INFOPBLIB

  • Reported release

    001

  • Status

    CLOSED CAN

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2008-06-02

  • Closed date

    2008-06-02

  • Last modified date

    2008-06-02

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

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

Fix information

Applicable component levels



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Document information


More support for:

z/OS family

Software version:

001

Operating system(s):

MVS

Reference #:

II14405

Modified date:

2008-06-02

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