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IC69352: A CLEAN HADR TAKEOVER PROCESS (WHILE THE DATABASES ARE IN PEER STATE) CAN BE SLOW IF THE HISTORY FILE IS VERY LARGE.

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APAR status

  • Closed as program error.

Error description

  • During a clean takeover process (while primary and standby
    databases are in peer sate), we make an unnecessary history
    cleanup call during rollforward recovery.  Original standby will
    call sqlprDoForwardPhase() to finish its rollforward call at the
    end of the takeover before the standby database becomes primary
    database.  During this call, we make a history cleanup call
    through sqlpCleanHistFile() for retrieved log files.
    
    In a clean takeover (while the databases are in peer state), no
    logs are really retrieved to complete the rollforward process on
    the standby before it becomes primary.  Hence, we should be able
    to skip this call to clean up the history file.  This will avoid
    performance issues during takeover for databases with large
    history files.
    

Local fix

  • Prune history to make the history file smaller in size.
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * Users using HADR on all platforms                            *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * HADR takeover is slow when database history file is large    *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Upgrade to DB2 v97fp3                                        *
    ****************************************************************
    

Problem conclusion

  • The problem is fixed in DB2 v97fp3. The performance of HADR
    takeover then has nothing to do with database history file size.
    

Temporary fix

Comments

APAR Information

  • APAR number

    IC69352

  • 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

    2010-06-21

  • Closed date

    2010-08-02

  • Last modified date

    2010-08-02

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

    IZ77372

  • 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

  • R910 PSN

       UP

  • R950 PSN

       UP

  • R970 PSN

       UP

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Document Information

Modified date:
02 August 2010