IBM Support

IT47328: HIGH MEMORY AND CPU USAGE BY DB2SYSC SEEN WHEN THERE IS SLOW RETRIEVE OF DATA FROM ARCHIVES.

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APAR status

  • Closed as program error.

Error description

  • Retrieving data from archives can perform slowly.
    
    The system statistics indicate high memory and cpu usage of
    db2sysc process.
    
    This has been seen in a Content Management environment
    retrieving documents.
    
    In dsminstr.log the following threads are seen performing
    slowly:
    
    PROCESS[7668652] TSM Client final instrumentation statistics:
    Tue Aug 27 13:00:23 2024
    Instrumentation class: API
    Completion status: Success
    Detailed Instrumentation statistics for
    Thread: 1 Elapsed time = 22.203 sec
    Section Actual(sec) Average(msec) Frequency used Bytes Involved
    ---------------------------------------------------------------
    --------------------
    Waiting on App 0.008 0.3 30 0
    API Send Data 2.571 257.1 10 0
    API Query 0.023 2.0 12 0
    API End Txn 19.293 9646.3 2 0
    API Misc 0.035 5.8 6 0
    Other 0.272 0.0 0 0
    ---------------------------------------------------------------
    --------------------
    PROCESS[7668652] Ended TSM Instrumentation Report: Tue Aug 27
    13:00:46 2024
    
    PROCESS[25953204] TSM Client final instrumentation statistics:
    Tue Aug 27 20:47:52 2024
    Instrumentation class: API
    Completion status: Success
    Detailed Instrumentation statistics for
    Thread: 1 Elapsed time = 6.417 sec
    Section Actual(sec) Average(msec) Frequency used Bytes Involved
    ---------------------------------------------------------------
    --------------------
    Waiting on App 0.017 0.7 23 0
    API Query 5.069 389.9 13 0
    API Get Data 0.711 88.9 8 0
    Other 0.619 0.0 0 0
    ---------------------------------------------------------------
    --------------------
    PROCESS[25953204] Ended TSM Instrumentation Report: Tue Aug 27
    20:47:59 2024
    
    PROCESS[25953204] TSM Client final instrumentation statistics:
    Wed Aug 28 00:01:22 2024
    Instrumentation class: API
    Completion status: Success
    Detailed Instrumentation statistics for
    Thread: 1 Elapsed time = 6.350 sec
    Section Actual(sec) Average(msec) Frequency used Bytes Involved
    ---------------------------------------------------------------
    --------------------
    Waiting on App 0.006 0.2 23 0
    API Query 5.210 400.7 13 0
    API Get Data 0.494 61.7 8 0
    Other 0.641 0.0 0 0
    ---------------------------------------------------------------
    --------------------
    PROCESS[25953204] Ended TSM Instrumentation Report: Wed Aug 28
    00:01:29 2024
    
    PROCESS[23790292] TSM Client final instrumentation statistics:
    Wed Aug 28 00:01:23 2024
    Instrumentation class: API
    Completion status: Success
    Detailed Instrumentation statistics for
    Thread: 1 Elapsed time = 5.798 sec
    Section Actual(sec) Average(msec) Frequency used Bytes Involved
    ---------------------------------------------------------------
    --------------------
    Waiting on App 0.007 0.2 30 0
    API Send Data 0.002 0.3 6 0
    API Query 0.023 1.9 12 0
    API End Txn 5.138 2569.0 2 0
    API Misc 0.055 9.1 6 0
    Other 0.574 0.0 0 0
    ---------------------------------------------------------------
    --------------------
    PROCESS[23790292] Ended TSM Instrumentation Report: Wed Aug 28
    00:01:29 2024
    
    In the activity log are seen the following related sessions:
    66474, 70221, 70987 and 70986:
    
    Session 66474:
    Date/Time: 27.08.2024 13:00:23 Message: ANR0400I Session 66474
    started for node ABCD (AIX) (ShMem). (SESSION: 66474)
    ...
    Date/Time: 27.08.2024 13:00:44 Message: ANR0511I Session 66474
    opened output volume  /filesystem/ABCD_1/0011D0B9.BFS. (SESSION:
    66474)
    ...
    Date/Time: 27.08.2024 13:00:45 Message: ANR0514I Session 66474
    closed volume  /filesystem/ABCD_1/0011D0B9.BFS. (SESSION: 66474)
    
    Date/Time: 27.08.2024 13:00:45 Message: ANR0514I Session 66474
    closed volume  /filesystem/0011D0B8.BFS. (SESSION: 66474)
    Date/Time: 27.08.2024 13:00:45 Message: ANR0403I Session 66474
    ended for node ABCD (AIX). (SESSION: 66474)
    
    Session 70221:
    Date/Time: 27.08.2024 20:47:53 Message: ANR0400I Session 70221
    started for node ABCD (AIX) (ShMem). (SESSION: 70221)
    ...
    Date/Time: 27.08.2024 20:47:59 Message: ANR8340I FILE volume
    /filesystem/ABCD_1/0011D0B7.BFS mounted. (SESSION: 70221)
    Date/Time: 27.08.2024 20:47:59 Message: ANR0510I Session 70221
    opened input volume  /filesystem/ABCD_1/0011D0B7.BFS. (SESSION:
    70221)
    Date/Time: 27.08.2024 20:47:59 Message: ANR0514I Session 70221
    closed volume  /filesystem/ABCD_1/0011D0B7.BFS. (SESSION: 70221)
    
    Date/Time: 27.08.2024 20:47:59 Message: ANR0403I Session 70221
    ended for node ABCD (AIX). (SESSION: 70221)
    
    Session 70987:
    Date/Time: 28.08.2024 00:01:23 Message: ANR0400I Session 70987
    started for node ABCD (AIX) (ShMem). (SESSION: 70987)
    Date/Time: 28.08.2024 00:01:24 Message: ANR8340I FILE volume
    /filesystem/ABCD_1/0011D0B7.BFS mounted. (SESSION: 70987)
    Date/Time: 28.08.2024 00:01:24 Message: ANR0511I Session 70987
    opened output volume  /filesystem/ABCD_1/0011D0B7.BFS. (SESSION:
    70987)
    Date/Time: 28.08.2024 00:01:24 Message: ANR8340I FILE volume
    /filesystem/0011D0B6.BFS mounted. (SESSION: 70987)
    Date/Time: 28.08.2024 00:01:24 Message: ANR0511I Session 70987
    opened output volume  /filesystem/0011D0B6.BFS. (SESSION: 70987)
    
    ...
    Date/Time: 28.08.2024 00:01:28 Message: ANR0514I Session 70987
    closed volume  /filesystem/ABCD_1/0011D0B7.BFS. (SESSION: 70987)
    
    Date/Time: 28.08.2024 00:01:28 Message: ANR0514I Session 70987
    closed volume  /filesystem/0011D0B6.BFS. (SESSION: 70987)
    Date/Time: 28.08.2024 00:01:28 Message: ANR0403I Session 70987
    ended for node ABCD (AIX). (SESSION: 70987)
    
    Session 70986:
    Date/Time: 28.08.2024 00:01:23 Message: ANR0400I Session 70986
    started for node ABCD (AIX) (ShMem). (SESSION: 70986)
    ...
    Date/Time: 28.08.2024 00:01:28 Message: ANR8340I FILE volume
    /filesystem/ABCD_1/0011D0B7.BFS mounted. (SESSION: 70986)
    Date/Time: 28.08.2024 00:01:28 Message: ANR0510I Session 70986
    opened input volume  /filesystem/ABCD_1/0011D0B7.BFS. (SESSION:
    70986)
    ...
    Date/Time: 28.08.2024 00:01:28 Message: ANR0514I Session 70986
    closed volume  /filesystem/ABCD_1/0011D0B7.BFS. (SESSION: 70986)
    
    Date/Time: 28.08.2024 00:01:28 Message: ANR0403I Session 70986
    ended for node ABCD (AIX). (SESSION: 70986)
    
    Looking at servermon data, it is seen that:
       In the case of session 66474 20,484 sec (from 22,955 sec) was
    spent in Thread Wait and from this 16,716 sec was spent in Tm
    Lock Wait.
       In the case of session 70221 5.032 sec (from 6.642 sec) was
    spent in DB2 MFtch Prep
    
    Thread 472816 SessionThread parent=354
    2024-08-27T20:47:53.023-->2024-08-27T20:47:59.665
    NODE_NAME:ABCD,SESSION:70221,SESSION_TYPE:NODE
    Session ID 70221 ABCD (AIX)
    Operation Count Tottime Avgtime Mintime Maxtime InstTput Total
    KB
    ---------------------------------------------------------------
    -------------
    Shmem Read 41 0.310 0.008 0.000 0.194 0.0 0
    Shmem Write 68 0.010 0.000 0.000 0.007 1737.1 19
    DB2 Fetch Prep 24 0.044 0.002 0.000 0.009
    DB2 MFtch Prep 14 5.032 0.359 0.000 5.008   <==
    DB2 Inser Prep 1 0.003 0.004 0.003 0.003
    DB2 Updat Prep 3 0.005 0.002 0.001 0.003
    DB2 Fetch Exec 58 0.034 0.001 0.000 0.019
    DB2 MFtch Exec 30 0.014 0.000 0.000 0.003
    DB2 Inser Exec 1 0.000 0.000 0.000 0.000
    DB2 Updat Exec 3 0.000 0.000 0.000 0.000
    DB2 Fetch 58 0.000 0.000 0.000 0.000
    DB2 MFetch 48 0.000 0.000 0.000 0.000
    DB2 Commit 23 0.029 0.001 0.000 0.009
    DB2 Rollback 2 0.000 0.000 0.000 0.000
    DB2 Reg Prep 16 0.047 0.003 0.000 0.009
    DB2 Reg Exec 17 0.044 0.003 0.000 0.013
    DB2 Reg Fetch 17 0.000 0.000 0.000 0.000
    DB2 Connect 2 0.025 0.013 0.012 0.012
    Decrypt Init 3 0.000 0.000 0.000 0.000
    Decrypt Data 3 0.000 0.000 0.000 0.000 0
    Decrypt Final 3 0.000 0.000 0.000 0.000
    Acquire Latch 25 0.000 0.000 0.000 0.000
    Acquire XLatch 4 0.000 0.000 0.000 0.000
    Sleep 1 0.300 0.300 0.300 0.300
    Thread Wait 9 0.581 0.065 0.000 0.564
    Unknown 0.154
    ---------------------------------------------------------------
    -------------
    Total 6.642 3.0 20
    
    The above confirms the performance bottleneck on Storage Protect
    server that this APAR addresses.
    
    There is a slow sql statement on the Storage Protect server:
    SELECT NODEID,DESCR,FSID,OBJTYPE,HL,LL,INSDATE,OBJID,RETINIT_DA
    TE,OWNER,CLNTTYPE,HLID,LLIDFROM "TSMDB1"."ARCHDESC_NAMEVIEW"
    
    WHERE
    
    (NODEID=? AND DESCR=? AND FSID=? AND OBJTYPE=? AND HLID=? AND
    LLID=?)
    
    FOR READ ONLY OPTIMIZE FOR 10 ROWS WITH UR
    
    which shows an index access IMARPARENT_NDX (NODEID, DESCR, FSID,
    PARENTHL with 3 columns and over 2 million distinct values in
    this example).
    
    The column "descr" has a bad distribution.
    On The table there are some constraints like:
    
    ALTER TABLE "TSMDB1 "."ARCHIVE_OBJECTS"
    ADD CONSTRAINT "IMAR_00" CHECK
    (NODEID >= 0 )
    NOT ENFORCED
    DISABLE QUERY OPTIMIZATION;
    
    which has an impact on the access path.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * All IBM Storage Protect server users.                        *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See error description.                                       *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Apply fixing level when available. This problem is currently *
    * projected to be fixed in level 8.1.26. Note that this is     *
    * subject to change at the discretion of IBM                   *
    ****************************************************************
    

Problem conclusion

  • This problem was fixed.
    Affected platforms: AIX, Linux, and Windows.
    

Temporary fix

Comments

APAR Information

  • APAR number

    IT47328

  • Reported component name

    TSM SERVER

  • Reported component ID

    5698ISMSV

  • Reported release

    81A

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2024-11-27

  • Closed date

    2025-02-13

  • Last modified date

    2025-02-13

  • 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

[{"Business Unit":{"code":"BU029","label":"Software"},"Product":{"code":"SSGSG7","label":"Tivoli Storage Manager"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"81A"}]

Document Information

Modified date:
29 March 2025