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PK50739: UNABLE TO RE-ESTABLISH A SESSION WITH A 3650 PIPELINE TERMINAL FOLLOWING THE SESSION DROPPING.

A fix is available

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APAR status

  • Closed as program error.

Error description

  • Following the dropping of a session between CICS and a
    3650 Pipeline terminal, the terminal can not get back in session
    with CICS.  When it attempts to get in session with CICS,
    the attempt fails with msgDFHZC2487 ' Session connection failed.
    Node unavailability return code 4. ((15) Module name: DFHZLGX) '
       There are still tasks running on the pool terminals and
    these tasks have been stuck in ZCIOWAITs since around the time
    of the session outage.  The presence of these tasks is what
    prevents CICS from cleaning up.  And the presence of these tasks
    causes a subsequent logon attempt to fail.
      These tasks are in syncpoint processing and trying to send
    data that was defered from a prior EXEC CICS SEND to the
    terminal.  Because they are in Syncpoint processing, they are
    protected from purge and forcepurge .
      The RPL associated with the pool TCTTEs that are
    associated with each of the hung tasks has a RTNCD/FDBK of
    0C0B .  RPLUSFLD (RPL+X'5C') of each of these RPLs contains
    the address of the session TCTTE.
      One of the messages issued at time of disconnect is
    DFHZC2431 ' Request to a released node '.
      The DTA for each of the tasks stuck in ZCIOWAIT on the
    deferred send to the pipeline terminal has the
    CANCEL_NORMAL bet set and AKC3 is set in
    CANCEL_DEFERRED_ABEND .
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED: All CICS users.                              *
    ****************************************************************
    * PROBLEM DESCRIPTION: MSGDFHZC2431 is reported against a 3650 *
    *                      pipeline terminal.                      *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    Tasks running on pipeline pool terminals remain in a ZCIOWAIT
    after message DFHZC2431 has been issued for the associated
    pipeline session TCTTE. Further attempts to reestablish the
    session between the pipeline session TCTTE and CICS result in
    msgDFHZC2487 ' Session connection failed. Node unavailability
    return code 4. ((15) Module name: DFHZLGX).
    The suspended tasks are in Syncpoint processing trying to send
    data that was deferred from a prior EXEC CICS SEND. As they are
    in Syncpoint processing, they are protected from purge and
    forcepurge.
    The ABTASK action for MSGDFHZC2431 invokes the ABEND TASK
    routine in DFHZNCE after label NEPIE01A. The ABEND TASK routine
    checks if there is a task associated with the terminal, but as
    it was passed the session TCTTE it finds no task (as these run
    against the pipeline pool terminals) and takes no action to
    resume the suspended tasks, which remain suspended indefinitely.
    
    Additional keywords: TWAOAT TWAOCT
    

Problem conclusion

  • Terminal Control error handling for the DFHZC2431 message has
    been changed for the case where DFHZNAC is driven with a
    Pipeline session terminal. In this case DFHZNAC will queue the
    associated Pipeline pool terminals for CANCEL TASK processing so
    that any tasks running against them can be cleaned up.
    

Temporary fix

  • FIX AVAILABLE BY PTF ONLY
    

Comments

APAR Information

  • APAR number

    PK50739

  • Reported component name

    CICSTS V3 Z/OS

  • Reported component ID

    5655M1500

  • Reported release

    400

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2007-08-09

  • Closed date

    2008-02-29

  • Last modified date

    2008-04-01

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

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

    PK55191 UK34212 UK34213

Modules/Macros

  •    DFHZNAC  DFHZNCA
    

Fix information

  • Fixed component name

    CICSTS V3 Z/OS

  • Fixed component ID

    5655M1500

Applicable component levels

  • R400 PSY UK34212

       UP08/03/06 P F803

  • R500 PSY UK34213

       UP08/03/06 P F803

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:
01 April 2008