IBM Support

IT27775: SLOW DATABASE ROLLFORWARD OR HADR REPLAY OF "REDUCE MAX" OPERATION

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APAR status

  • Closed as program error.

Error description

  • Database rollforward or HADR replay of REDUCE MAX operation will
    progress with a lower rate than it is required to ensure data
    consistency.
    Whilst a record of this type is replayed, in the backtrace of
    all engine threads one  will see all redo
    workers (db2redow EDUs) but one waiting in:
    
    sqlprWaitDuringPRec
    sqlprFindQueue
    sqlpPRecProcLog
    sqlpParallelRecovery
    sqleSubCoordProcessRequest
    
    and a single EDU with sqlbMoveOneExtent or sqlbRedoFreeExtents
    function on the stack, e.g.:
    
    sqlbMoveOneExtent
    sqlbRedoUpdateEMP
    sqlbRedo
    sqldmrdo
    sqlpRecDbRedo
    sqlpPRecProcLog
    sqlpParallelRecovery
    
    This is caused by a too high level of synchronization for log
    records of this type. This APAR will relax the restriction and
    allow for a faster processing of log records, that affect other
    tablespaces, whilst "REDUCE MAX" is running.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * ALL                                                          *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See Error Description                                        *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Upgrade to Db2 11.1 Mod 4 Fixpack 5 or higher                *
    ****************************************************************
    

Problem conclusion

  • First fixed in Db2 11.1 Mod 4 Fixpack 5
    

Temporary fix

Comments

APAR Information

  • APAR number

    IT27775

  • 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

    2019-01-15

  • Closed date

    2020-01-16

  • Last modified date

    2020-01-16

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

    IT27769

  • 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 PSN

       UP

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Document Information

Modified date:
16 January 2020