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IC90006: SMALL PRIVATE MEMORY LEAK ON THE DB2 SERVER EVERY TIME AN OPTIMIZATION PROFILE IS LOADED

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You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • A small amount of private memory is leaked when an optimization
    profile is first accessed.  SAP systems are vulnerable through
    the use of the DB2WORKLOAD=SAP registry setting.
    
    In most cases, the memory leak is minimal, as optimizer profile
    information is cached in the catalog cache.  The leak only
    occurs when the profile is loaded into the cache, i.e. on the
    first access after database activation, and on subsequent
    accesses only if the profile has been evicted from the cache
    (due to limited space/configuration).
    
    On SAP systems, the leak is only likely to be significant when
    the package cache is constrained, causing frequent statement
    recompilations.
    
    The memory leak is outside of DB2's memory manager, so it cannot
    be seen by DB2 diagnostic tools.  It can only be monitored as
    part of overall private memory usage by the db2sysc/db2syscs.exe
    process.  The best way to identify the problem is:
    - confirm vulnerability
    - monitor the catalog cache and package cache hit ratio
    - assess the catalog cache/package cache configuration
    - confirm that private memory usage for the db2sysc process is
    growing consistently over time
    

Local fix

  • Increase the catalog cache setting (catalogcache_sz) and/or the
    package cache setting (pckcachesz)
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * systems using optimizer profiles or with DB2_WORKLOAD=SAP    *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See Error Description                                        *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Upgrade to DB2 Version 9.7 Fix Pack 9                        *
    ****************************************************************
    

Problem conclusion

  • Problem first fixed in DB2 Version 9.7 Fix Pack 9
    

Temporary fix

  • See Local Fix
    

Comments

APAR Information

  • APAR number

    IC90006

  • 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

    2013-02-04

  • Closed date

    2013-12-18

  • Last modified date

    2013-12-18

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

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

    IC90008 IC90009 IC95438

Modules/Macros

  • sqno
    

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 #: IC90006

Modified date: 18 December 2013