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PM52409: DBAT NOT POOLED AFTER SERVICING CONNECTION TERMINATION

A fix is available

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APAR status

  • Closed as program error.

Error description

  • DB2DDF DB2INACTIVE defects pm52409 dpm52409
    DDF Thread not pooled after servicing connection termination.
    The absence of the pooled (DISCONN) DBAT may therefore require
    a new DBAT to be created to service new work. The expense to
    to create a new DBAT, as opposed to reusing a DISCONN DBAT that
    could have otherwise been available, may impact performance.
    ***************************************************************
    Additional symptoms and keywords:
     DSN6FAC CMTSTAT INACTIVE
     DSNTIPR DDF THREADS INACTIVE
     ABEND04E AB04E S004E 04E
       04E-00E20016 00E20016 RC00E20016 DSNSVSTK DSNSVSTK+0634 0634
       This symptom can occur due to increased thread terminations
       that may be required. As new DBATs are created and then
       (unnecessarily) terminated in order to service a connection
       termination, the increased activity of creating and then
       quickly terminating the DBAT may cause an accumulation of
       stack storage and high contention of the VLCASAGT latch.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED: All Distributed Data Facility (DDF) users.   *
    *                 Specifically those where DB2 is configured   *
    *                 with DDF THREADS=INACTIVE (DSN6FAC CMTSTAT   *
    *                 INACTIVE). DB2 10 for z/OS users only.       *
    ****************************************************************
    * PROBLEM DESCRIPTION: DDF server threads (DBATs) are not      *
    *                      pooled after servicing a connection     *
    *                      termination from a remote system.       *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    DBATs are no longer pooled after servicing a connection
    termination relative to a remote client system. The absence of
    the pooled (DISCONN) thread could impact performance since a
    DBAT would have to be created - instead of one being readily
    available - to service new work from other, new or existing,
    connections.
    

Problem conclusion

  • DB2 10 for z/OS is changed to restore DBAT pooling behavior
    after a connection termination is serviced.
    

Temporary fix

Comments

APAR Information

  • APAR number

    PM52409

  • Reported component name

    DB2 OS/390 & Z/

  • Reported component ID

    5740XYR00

  • Reported release

    A10

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2011-11-16

  • Closed date

    2011-12-06

  • Last modified date

    2012-03-19

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

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

    UK74520

Modules/Macros

  • DSNLQCTL DSNLQDIS
    

Fix information

  • Fixed component name

    DB2 OS/390 & Z/

  • Fixed component ID

    5740XYR00

Applicable component levels

  • RA10 PSY UK74520

       UP11/12/21 P F112

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:
19 March 2012