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IC66944: SETTING PRIORITY OF EDU VIA DB2_RESOURCE_POLICY EDU_PRIORITY DOESN'T WORK ON LINUX

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APAR status

  • Closed as program error.

Error description

  • Setting priority of an EDU (DB2's engine thread) via
    DB2_RESOURCE_POLICY EDU_PRIORITY doesn't work on Linux.  For
    example, given the following setting,
    
    >> db2set
    DB2_RESOURCE_POLICY=/home/db2inst1/loggerpri.cfg
    >> cat loggerpri.cfg
    <RESOURCE_POLICY>
       <SCHEDULING_POLICY>
          <PRIORITY_VALUE>75</PRIORITY_VALUE>
          <EDU_PRIORITY>
             <EDU_NAME>db2loggw</EDU_NAME>
             <PRIORITY_VALUE>60</PRIORITY_VALUE>
          </EDU_PRIORITY>
       </SCHEDULING_POLICY>
    </RESOURCE_POLICY>
    
    All EDUs should have the priority of 75, except the db2loggw
    (log writer), which should have 60.  However, none of them has
    any priority change.  This APAR will address this problem.
    
    Note that one can view the priority of DB2 EDUs by
    cross-referencing 'ps -lLfp <PID of db2sysc>' and 'db2pd -edus'.
    
    Also note that changing priority of EDUs can greatly impact the
    overall performance of DB2 as well as the server both positively
    and negatively.  Only experienced DBAs should make use of it
    after a large amount of tests.
    

Local fix

  • To change the priority of DB2 EDU's without DB2_RESOURCE_POLICY,
    one can manually run renice command.
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * DB2 servers on Linux platform that makes use of              *
    * DB2_RESOURCE_POLICY registry variable                        *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * Same as ERROR DESCRIPTION                                    *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Upgrade to DB2 9.7 Fix Pack 2 or later.                      *
    ****************************************************************
    

Problem conclusion

  • Fixed in DB2 9.7 Fix Pack 2.
    

Temporary fix

Comments

APAR Information

  • APAR number

    IC66944

  • 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

    2010-03-06

  • Closed date

    2010-04-08

  • Last modified date

    2010-04-08

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

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

    IC67205

Fix information

  • Fixed component name

    DB2 FOR LUW

  • Fixed component ID

    DB2FORLUW

Applicable component levels

  • R970 PSN

       UP

[{"Line of Business":{"code":"LOB10","label":"Data and AI"},"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":"9.7"}]

Document Information

Modified date:
16 September 2021