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PK32714: S8 TCBS GET STUCK IN DISPATCH SSL_POOL WAITS DUE TO INCOMPLETE TERMINATION LEADING TO SIMILAR SYMPTOMS AS PK24822.

A fix is available

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APAR status

  • Closed as program error.

Error description

  • All S8 TCBs are stuck in DISPATCH SSL_POOL waits, all the WEB
    requests are waiting for S8 due to incomplete dispatch TCB
    terminations. The same problem symptoms described by PK24822.
    Customer has PK24822 fix on.
    However, this case dsg_tcb_det_dirty(x'34') has 14,
    dsg_tcb_det_excess(x'3C') has zero.
    The problem results in S8 TCBs being deleted by tasks
    which get marked unclean before they release the S8 they are
    using.
    Tasks are most likely to be marked unclean when they receive a
    critical error procesing a DB2 request. In the dump, we saw
    a number of AD2U abends occur.
    Additional symptoms:
    CWBA tasks waiting on resource DISPATCH OPEN_DEL or DISPATCH
    OPENPOOL. Tasks waiting on OPEN_DEL are waiting to steal a TCB.
    Kernel stacks for these tasks show that the suspends are
    issued in DFHDSDS4 in routine STEAL_TCB (for OPEN_DEL tasks) or
    AWAIT_TCB (for OPENPOOL tasks). The STEAL_TCB routine finds a
    target TCB to steal, then suspends until that TCB is detached.
    There are lots of S8 TCBs that are in termination processing
    and show DELETE_TCB_REQUESTED and DELETE_TCB_COMPLETE, yet the
    TCB will never terminate.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED: All.                                         *
    ****************************************************************
    * PROBLEM DESCRIPTION: Several tasks stuck in DISPATCH         *
    *                      SSL_POOL waiting on S8 TCBs.            *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    A program defined to be processed by an OPEN TCB is invoked
    from a web browser to run on a CICS-SSL region. This will
    create S8 TCBs. If the task abends when it is on an OPEN TCB
    it may get flagged as UNCLEAN. This causes the S8 TCBs to
    experience DELETE_TCB which can never complete and they will
    be left in a 'being terminated' state.
    As a result, the SSL_POOL will eventually become depleted and
    new tasks that require S8 TCBs will get stuck in DISPATCH
    waits.
    
    Additional Keywords: PK24822 FREE_OPEN_TCB MAXSSLTCBS
    

Problem conclusion

  • DFHDSAT has been altered so we do not attempt to delete S8 TCBs.
    

Temporary fix

  •             *********
                * HIPER *
                *********
    FIX AVAILABLE BY PTF ONLY
    

Comments

APAR Information

  • APAR number

    PK32714

  • Reported component name

    CICSTS 3.1 Z/OS

  • Reported component ID

    5655M1500

  • Reported release

    400

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    YesHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2006-10-10

  • Closed date

    2006-12-11

  • Last modified date

    2007-01-03

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

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

    UK20513

Modules/Macros

  •    DFHDSAT  DFHDSKE  DFHDSSUB
    

Fix information

  • Fixed component name

    CICSTS 3.1 Z/OS

  • Fixed component ID

    5655M1500

Applicable component levels

  • R400 PSY UK20513

       UP06/12/14 P F612

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 January 2007