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IT32654: ACTIVITY EVENT MONITORS RETURN INCORRECT CPU TIME FOR SP CALLS WITH NESTED STATEMENTS

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You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • If you have defined activity event monitors to get CPU times for
    stored procedures with nested statements, you may get incorrect
    results.
    
    Example :
    
    CREATE PROCEDURE SP1 (
    IN IN_STMT VARCHAR(10000)
    )
    LANGUAGE SQL
    SPECIFIC EXECSQL
    MODIFIES SQL DATA
    NOT DETERMINISTIC
    COMMIT ON RETURN NO
    NO EXTERNAL ACTION
    BEGIN
    EXECUTE IMMEDIATE in_stmt;--
    END@
    
    
    CREATE EVENT MONITOR "DB2ACTIVITIES"
    FOR ACTIVITIES
    WRITE TO TABLE ACTIVITY (TABLE ACTIVITY_DB2ACTIVITIES"),
    ACTIVITYMETRICS (TABLE "ACTIVITYMETRICS_DB2ACTIVITIES"),
    ACTIVITYSTMT (TABLE ACTIVITYSTMT_DB2ACTIVITIES"),
    ACTIVITYVALS (TABLE "ACTIVITYVALS_DB2ACTIVITIES"),
    CONTROL (TABLE "CONTROL_DB2ACTIVITIES")
    AUTOSTART@
    
    
    call sp ( 'delete from tab1 where 1=1')
    
    db2 "SELECT UOW_ID,ACTIVITY_ID,SYSTEM_CPU_TIME,USER_CPU_TIME
    From ACTIVITY_DB2ACTIVITIES"
    
    UOW_ID ACTIVITY_ID SYSTEM_CPU_TIME USER_CPU_TIME
    ----------- -------------------- --------------------
    --------------------
    1007 2 21 2616
    1007 1 374 5752
    
    $ db2 "SELECT UOW_ID,ACTIVITY_ID, SUBSTR(STMT_TEXT, 1,70) AS
    STMT_TEXT FROM ACTIVITYSTMT_DB2ACTIVITIES"
    
    UOW_ID ACTIVITY_ID STMT_TEXT
    ----------- --------------------
    ----------------------------------------------------------------
    ------
    1007 2 delete from cpu where 1=1
    1007 1 CALL sp1(?)
    
    CPU time for the SP is twice the CPU time of the delete.
    

Local fix

  • Use TOTAL_CPU_TIME returned by ACTIVITYMETRICS
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * All Db2 users                                                *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See Error Description                                        *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Upgrade to at least Db2 11.1 Mod 4 Fix Pack 6                *
    ****************************************************************
    

Problem conclusion

  • Problem was first fixed Db2 11.1 Mod 4 Fix Pack 6
    

Temporary fix

Comments

APAR Information

  • APAR number

    IT32654

  • Reported component name

    DB2 FOR LUW

  • Reported component ID

    DB2FORLUW

  • Reported release

    B10

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2020-04-25

  • Closed date

    2021-03-19

  • Last modified date

    2021-03-19

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

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

Fix information

  • Fixed component name

    DB2 FOR LUW

  • Fixed component ID

    DB2FORLUW

Applicable component levels

  • RB10 PSY

       UP

[{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SSEPGG","label":"DB2 for Linux- UNIX and Windows"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"11.1","Line of Business":{"code":"LOB10","label":"Data and AI"}}]

Document Information

Modified date:
04 May 2022