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IZ26166: STMM TARGET MEMORY CONSUMPTION TOO HIGH WHEN INSTANCE_MEMORY SET TO VALUE OTHER THAN AUTOMATIC

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You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • STMM database memory usage targets are too high when
    INSTANCE_MEMORY is set to some value (non-AUTOMATIC).
    This means that DB2 does not leave enough memory free/available
    at the partition level to handle normal volatility.
    This results in out-of-memory errors.
    
    The specific problems addressed in this APAR are :
    
    1. When target memory is too high,
       STMM may try to perform a bufferpool increase
       when it should abort the attempt.  This is due
       to an invalid check for available free memory.
    
       The result is that memory may become overcommitted.
       Other memory requirements may fail at the point when
       instance memory becomes exhausted.
       (thus... statement compilation fails with SQL0101).
    
    2. Database Memory overflow is double counted in the calculation
       of target memory consumption.  This can result in targets
       that are too high, potentially resulting in out of memory
       errors.
    

Local fix

Problem summary

  • Users affected:
      Systems configured to self-tune DATABASE MEMORY (AUTOMATIC)
      with STMM AND configured with a hard-coded INSTANCE
      MEMORY VALUE (default is AUTOMATIC).
    
    Problem Description:
      See Error description
    
    Problem Summary:
      See Error Description
    

Problem conclusion

  • First fixed in DB2 UDB Version 9.5 Fixpak 2
    

Temporary fix

  • set DATABASE_MEMORY to a fixed value
    or use the default AUTOMATIC setting for INSTANCE_MEMORY
    

Comments

APAR Information

  • APAR number

    IZ26166

  • Reported component name

    DB2 UDB ESE AIX

  • Reported component ID

    5765F4100

  • Reported release

    950

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2008-07-02

  • Closed date

    2008-09-16

  • Last modified date

    2009-06-16

  • 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 UDB ESE AIX

  • Fixed component ID

    5765F4100

Applicable component levels

  • R950 PSN

       UP



Document information

More support for: DB2 for Linux, UNIX and Windows

Software version: 950

Reference #: IZ26166

Modified date: 16 June 2009


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