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IC90150: "MEMORY LEAK" ISSUE IN PACKAGE CACHE.

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You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • If DB2 failed to compile a dynamic SQL statement, it'd drop the
    statement to free the space in package cache. However DB2 would
    fail to drop the statement if there's latch contention.
    As a result, the statement is left in package cache and the
    space will never be freed or reused, even if the "flush package
    cache dynamic" statement is performed.
    
    A typical compilation error is SQL1415N which simply means the
    SQL statement is to trigger some internal setting, but not to be
    executed. For example, when the "db2Import()" API is called it
    internally issues a "SET QUERY PATROLLER BYPASS" statement which
    leads to SQL1415N during compilation.
    
    To identify the problem, it'd be good if DB2 trace (db2trc) data
    can be gathered to confirm all details.
    If DB2 trace data can not be gathered, please check the "Dynamic
    SQL Variations" data in package cache by following steps:
    1) Issue "flush package cache dynamic" statement.
    2) Issue "db2pd -dynamic -db <dbname>" command then check data
    in the "Dynamic SQL Variations" section.
    For a "leaked" variation, the "Val Insert Time" is an old time
    and the "NumRef" is 0. Here is an example of 'db2pd' output:
    ===========================================
    Address            AnchID StmtUID    NumEnv     NumVar
    NumRef     NumExe     Text
    0x07000009D572AB80 477    23169      1          0          0
    0          SET QUERY PATROLLER BYPASS =    'FALSE'
    0x07000009C526F740 456    9437       1          0          0
    0          SET QUERY PATROLLER BYPASS =    'TRUE'
    
    Dynamic SQL Variations:
    Address            AnchID StmtUID    EnvID      VarID
    NumRef     Typ Lockname                   Val Insert Time
    Sect Size
    0x07000009AF526180 477    23169      1          33019676   0
    0   0000280701F7D71C00013BA256 N   2013-01-18-13.25.27.870141 0
    
    0x07000008559BB300 477    23169      1          33019091   0
    0   0000280701F7D4D300013BA256 N   2013-01-18-13.23.56.546901 0
    
    0x07000009B8652C80 477    23169      1          33018776   0
    0   0000280701F7D39800013BA256 N   2013-01-18-13.22.40.039870 0
    
    ......
    0x07000009B4209560 456    9437       1          18830274   0
    0   0000218F011F53C20001390256 N   2013-01-18-13.25.30.803808 0
    
    0x07000009B0220DE0 456    9437       1          18829964   0
    0   0000218F011F528C0001390256 N   2013-01-18-13.24.48.168895 0
    
    0x070000093A5E54E0 456    9437       1          18829943   0
    0   0000218F011F52770001390256 N   2013-01-18-13.24.47.844114 0
    
    ===========================================
    

Local fix

  • Issuing "flush package cache dynamic" statement less frequently,
    to lessen the chances of latch contention.
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * All users of version 9.7 on Linux, Unix and Windows          *
    * platforms.                                                   *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See Error Description                                        *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Update to DB2 LUW Version 9.7 Fix Pack 9 or higher levels.   *
    ****************************************************************
    

Problem conclusion

  • First fixed in DB2 LUW Version 9.7 Fix Pack 9.
    

Temporary fix

  • Issuing "flush package cache dynamic" statement less frequently,
    to lessen the chances of latch contention.
    

Comments

APAR Information

  • APAR number

    IC90150

  • 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

    2013-02-12

  • Closed date

    2013-10-07

  • Last modified date

    2013-10-07

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

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

    IC94988 IC95512

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 #: IC90150

Modified date: 07 October 2013