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IC77979: UPON DATABASE TERMINATION DURING ROLLFORWARD OR RECOVER PENDING,PAGE CLEANER MAY EXIT WITH A NON-EMPTY DIRTY LIST

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APAR status

  • Closed as program error.

Error description

  • A database that is either in the recover pending or rollforward
    pending state is being terminated. Part of this termination is
    flushing changed (a.k.a. dirty) buffer pool pages to the disk.
    Under extremely rare timing circumstances, a page cleaner may
    end up dispatching a batch of asynchronous IO requests for the
    dirty pages to be written out, but the page cleaner gets
    terminated before collecting these asynchronous IO requests back
    from the operating system. This will cause that the dirty
    list(s) where the dirty pages reside will never be cleaned up,
    and a message similar to the following one will be seen in the
    DB2 diagnostic log:
    
    2011-06-23-11.49.06.227093-420 I179122E1061        LEVEL: Severe
    PID     : 14755                TID  : 47851803502912PROC :
    db2sysc
    INSTANCE: db2inst1             NODE : 000
    EDUID   : 644                  EDUNAME: db2pclnr (SAMPLE)
    FUNCTION: DB2 UDB, buffer pool services, sqlbClnrTerm, probe:10
    DATA #1 : String, 68 bytes
    ClnrTerm: Exiting with a non-empty dirty list.Please contact
    askBPS.
    
    These messages should only have a cosmetic impact. Since the IO
    requests have been submitted to the operating system, they are
    not lost, the page cleaner merely fails to collect the requests.
    It should be noted that this is a very rare timing problem that
    has only been found during deep ad-hoc testing. The problem does
    not affect AIX unless the default AIO collect method (IOCP) is
    disabled via the DB2_USE_IOCP registry variable.
    

Local fix

  • None (none needed)
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * see APAR description                                         *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * see APAR description                                         *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Upgrade to DB2 UDB 9.7 FixPack 6                             *
    ****************************************************************
    

Problem conclusion

  • Problem first fixed in DB2 UDB 9.7 FixPack 6
    

Temporary fix

Comments

APAR Information

  • APAR number

    IC77979

  • 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

    2011-08-08

  • Closed date

    2012-06-04

  • Last modified date

    2012-06-04

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

    IC77960

  • 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

  • R970 PSN

       UP



Document information

More support for: DB2 for Linux, UNIX and Windows

Software version: 9.7

Reference #: IC77979

Modified date: 04 June 2012