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IT07676: SLOW "GENERATE BACKUPSETS" WITH POOR PERFORMANCE READING FROM BFIM_AGGREGATES

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APAR status

  • Closed as program error.

Error description

  • The Tivoli Storage Manager server "generate backupset" process
    performs poorly when DB2 uses a different index as intended.
    This happens though the REORG status of the tables/indexes are
    fine and the RUNSTATS data are current.
    This leads to unnecessary index reads slowing down the "generate
    backupset" processing, e.g. a backupset generation which takes
    in common two days, take weeks to complete.
    
    Customer/L2 Diagnostics (If Applicable):
    The instrumentation trace may show a high value in the "DB2
    MFtch Exec" section for the ProcessNodesThread:
    
    Thread 4158482 ProcessNodesThread ...
    Operation       Count  Tottime  Avgtime  Mintime  Maxtime
    InstTput   Total KB
    ----------------------------------------------------------------
    ------------
    DB2 Fetch Prep    287    0.049    0.000    0.000    0.000
    DB2 MFtch Prep    286    0.068    0.000    0.000    0.000
    DB2 Fetch Exec   4611    0.731    0.000    0.000    0.009
    DB2 MFtch Exec   1002 1210.283    1.208    0.000    9.595
    DB2 Inser Exec   1154    0.210    0.000    0.000    0.000
    [...]
    
    The collectstmt instrumentation output shows that the above
    thread spends the most time running the following query:
    [...]
    Execution Time: 1208.922 sec, Number of Executions: 143,
    RowsReturned:  1159
    SELECT
    NODEID,FSID,OBJTYPE,HL,LL,STATE,INSDATE,OBJID,DEACDATE,OBJINFO,O
    WNER,MCI
    D,CGID,EXTOBJID,EXTTOKEN,GROUPTYPE,GROUPID,METADATASIZE FROM
    "TSMDB1"."BFIM_AGGREGATES"  WHERE (NODEID=? AND FSID>=? AND
    SUPERBFID=?) AND (NODEID=? AND FSID<=? AND SUPERBFID=?) ORDER
    BY OBJID FOR READ ONLY WITH UR --4158482
    [...]
    
    
    Tivoli Storage Manager Versions Affected:
    Tivoli Storage Manager server: All versions, All platforms
    
    Initial Impact: Medium
    
    Additional Keywords:
    TSM, BFIM_AGGREGATES, worse, performance, zz63, zz71, zz62
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * All Tivoli Storage Manager server users.                     *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See ERROR DESCRIPTION.                                       *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Apply fixing level when available. This problem is currently *
    * projected to be fixed in levels 6.3.6 and 7.1.3. Note that   *
    * this is subject to change at the discretion of IBM.          *
    ****************************************************************
    

Problem conclusion

  • This problem was fixed.
    Affected platforms:  AIX, HP-UX, Solaris, Linux, and Windows.
    

Temporary fix

Comments

APAR Information

  • APAR number

    IT07676

  • Reported component name

    TSM SERVER

  • Reported component ID

    5698ISMSV

  • Reported release

    63L

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2015-03-17

  • Closed date

    2015-04-02

  • Last modified date

    2015-04-02

  • 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

    TSM SERVER

  • Fixed component ID

    5698ISMSV

Applicable component levels

  • R63A PSY

       UP

  • R63H PSY

       UP

  • R63L PSY

       UP

  • R63S PSY

       UP

  • R63W PSY

       UP

  • R71A PSY

       UP

  • R71H PSY

       UP

  • R71L PSY

       UP

  • R71S PSY

       UP

  • R71W PSY

       UP



Document information

More support for: Tivoli Storage Manager

Software version: 63L

Reference #: IT07676

Modified date: 02 April 2015