IBM Support

IC66094: STMM TUNING FAILS DUE TO EXCESS OVERFLOW MEMORY

Subscribe

You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • PROBLEM DESCRIPTION:
    ====================
    When an Instance Memory limit is in effect, STMM may report a
    failure to increase a consumer as follows :
    
    2009-12-07-17.38.38.253963-480 I9251233A639       LEVEL: Warning
    PID     : 2203778              TID  : 21131       PROC : db2sysc
    0
    INSTANCE: db2inst1              NODE : 000         DB   : SAMPLE
    APPHDL  : 0-163                APPID: *LOCAL.DB2.091114224558
    AUTHID  : db2inst1
    EDUID   : 21131                EDUNAME: db2stmm (SAMPLE) 0
    FUNCTION: DB2 UDB, Self tuning memory manager,
    stmmCheckIfFreeMemoryIsEnoughForSizeIncr, probe:652
    MESSAGE : ZRC=0xFFFFEC49=-5047
    DATA #1 : String, 150 bytes
    There is not enough free memory for size increase. Free memory
    in pages:
    Physical memory = 2012001, Instance memory = 628208, Database
    memory = 461568
    
    This is caused by an inconsistency in the treatment of excess
    database overflow memory.  STMM considers excess database
    overflow memory as available instance memory, meaning it can be
    used or reclaimed for any desired configuration increases.
    
    Before performing any individual tuning increase, STMM performs
    a sanity check to make sure there is still available instance
    memory. The problem is that this check does not consider excess
    overflow to be available instance memory. This discrepancy can
    result in STMM failing to perform a planned
    tuning increase.
    
    Having enough excess database overflow memory to trigger this
    problem is not common. It may occur, for example, when utilities
    complete which were using more utility heap than configured
    (this is allowed as utility heap is a soft limit).
    
    
    The warning can be ignored. After performing tuning changes
    (including any failed increase), database memory overflow is
    retuned. This overflow tuning step releases excess database
    overflow memory, and it will be available for any tuning
    increases on the next STMM tuning cycle.
    
    
    
    db2diag.log:
    ==========
    2009-12-07-17.38.38.253963-480 I9251233A639       LEVEL: Warning
    PID     : 2203778              TID  : 21131       PROC : db2sysc
    0
    INSTANCE: db2app               NODE : 000         DB   : APP
    APPHDL  : 0-163                APPID: *LOCAL.DB2.091114224558
    AUTHID  : NAGIOS
    EDUID   : 21131                EDUNAME: db2stmm (APP) 0
    FUNCTION: DB2 UDB, Self tuning memory manager,
    stmmCheckIfFreeMemoryIsEnoughForSizeIncr, probe:652
    MESSAGE : ZRC=0xFFFFEC49=-5047
    DATA #1 : String, 150 bytes
    There is not enough free memory for size increase. Free memory
    in pages:
    Physical memory = 2012001, Instance memory = 628208, Database
    memory = 461568
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * Systems configured for STMM tuning of Database Memory        *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See Error Description                                        *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Errors have limited impact and are very intermittent.  It is *
    * recommend to ignore the errors unless they are very          *
    * frequent.                                                    *
    ****************************************************************
    

Problem conclusion

  • Problem first fixed in DB2 UDB 9.7 Fix Pack 4
    

Temporary fix

  • n/a
    

Comments

APAR Information

  • APAR number

    IC66094

  • 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

    2010-02-04

  • Closed date

    2011-04-29

  • Last modified date

    2011-04-29

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

    IC66006

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

    IC71563

Fix information

  • Fixed component name

    DB2 FOR LUW

  • Fixed component ID

    DB2FORLUW

Applicable component levels

  • R970 PSN

       UP

[{"Business Unit":{"code":"BU048","label":"IBM Software"},"Product":{"code":"SSEPGG","label":"DB2 for Linux, UNIX and Windows"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"9.7","Edition":"","Line of Business":{"code":"LOB10","label":"Data and AI"}}]

Document Information

Modified date:
29 April 2011