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IT05485: STMM LOCKLIST TUNING DECREASES FAIL REPETITIVELY ATTEMPTING TO REDUCE LOCKLIST SIZE MORE THAN WHAT CAN BE FREED

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APAR status

  • Closed as program error.

Error description

  • The STMM tuner may log frequent messages to the STMM log files
    about failing to decrease the Locklist.  This is because the
    calculation is based on locklist "in use", with the assumption
    that remaining locklist "not in use" can be freed.  However,
    some of the "not in use" locklist may be spread around on
    partially-used larger units of memory managed within the
    locklist, and those areas cannot be freed.  The STMM tuner needs
    to determine how many larger units of memory are completely free
    in order to correctly determine the maximum possible reduction
    in locklist size.
    
    STMM log messages about locklist decrease tuning failures appear
    similar to :
    
    EDUID   : 99999               EDUNAME: db2stmm (SAMPLE) 0
    FUNCTION: DB2 UDB, Self tuning memory manager,
    stmmUpdateDBConfig, probe:290
    MESSAGE : ZRC=0x82AE00A6=-2102525786=STMM_DYNAMIC_UPDATE_FAILED
              "STMM dynamic update failed"
    DATA #1 : String, 78 bytes
    Dynamic update failed for parameter Locklist. Attempted update
    value is 100000
    
    Note that isolated appearances of these messsages may still be
    normal due to timing.  Even when repetitive messages occur, the
    impact on STMM tuning overall is minimal.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * Systems using STMM to tune LOCKLIST                          *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See Error Description                                        *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Problem is cosmetic and can be ignored                       *
    ****************************************************************
    

Problem conclusion

  • Problem first fixed in DB2 Version 9.7 Fix Pack 11
    

Temporary fix

Comments

APAR Information

  • APAR number

    IT05485

  • Reported component name

    DB2 FOR LUW

  • Reported component ID

    DB2FORLUW

  • Reported release

    970

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2014-11-10

  • Closed date

    2015-10-23

  • Last modified date

    2015-10-23

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

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

Modules/Macros

  • stmm
    

Fix information

  • Fixed component name

    DB2 FOR LUW

  • Fixed component ID

    DB2FORLUW

Applicable component levels

  • R970 PSN

       UP



Document information

More support for: DB2 for Linux, UNIX and Windows

Software version: 9.7

Reference #: IT05485

Modified date: 23 October 2015