IC83184: NO AVAILABLE BUFFER POOL PAGES IN BUFFER POOL BLOCK AREA

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You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • This problem is only affecting block-based buffer pools. When a
    large number of sequential prefetch requests is serviced by a
    single buffer pool, the block area of the buffer pool may become
    permanently occupied by pages that can never be removed from the
    buffer pool. The eyecatcher is SQLB_BPFULL reported by
    sqlbFreeUpBlock() in the diagnostic log, for example:
    
    2012-03-29-19.09.01.604728-300 I6250582A498 LEVEL: Warning
    PID : 7667754 TID : 12338 PROC : db2sysc 0
    INSTANCE: db2inst1 NODE : 000
    EDUID : 12338 EDUNAME: db2pfchr (SAMPLE) 0
    FUNCTION: DB2 UDB, buffer pool services, sqlbFreeUpBlock,
    probe:20
    MESSAGE : ZRC=0x8502002C=-2063466452=SQLB_BPFULL
    "no available buffer pool pages"
    DATA #1 : <preformatted>
    Buffer pool 2 (BP_8K) is full.
    This message will be suppressed for 60 minutes.
    
    This error is not to be confused with legitimate "buffer pool
    full" errors. In the normal "buffer pool full" case, the error
    disappears once the workload decreases; for this case it is
    recommended to tune the buffer pool. In the malicious case,
    SQLB_BPFULL will persist regardless of the workload until the
    next database restart, and no tuning can alleviate the error.
    Also, a buffer pool contents dump (to be taken by DB2 Support
    Analyst) will reveal that the block area is permanently occupied
    by a relatively small number of pages that are located on
    so-called "alternate hate lists" (term understood by DB2
    Service).
    
    Upon encountering SQLB_BPFULL from sqlbFreeUpBlock(), DB2 will
    revert to using the page-based area of the buffer pool, and no
    application error will be returned. This means that in many
    cases, the impact will be unnoticeable. However, the permanent
    presence of the error may compromise the performance of
    sequential prefetching.
    
    WORKAROUND:
    1. Restart the database (deactivate/activate), OR
    2. If feasible, revert to using page-based buffer pools only.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * All                                                          *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See Error description listed above.                          *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Upgrade to DB2 9.7 FP7 or subsequent fix pack.               *
    ****************************************************************
    

Problem conclusion

  • Problem First Fixed in DB2 Version 9.7 Fix Pack 7
    

Temporary fix

Comments

APAR Information

  • APAR number

    IC83184

  • 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

    2012-05-07

  • Closed date

    2012-10-26

  • Last modified date

    2012-11-28

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

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

    IC87853

Fix information

  • Fixed component name

    DB2 FOR LUW

  • Fixed component ID

    DB2FORLUW

Applicable component levels

  • R970 PSN

       UP



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Document information


More support for:

DB2 for Linux, UNIX and Windows

Software version:

9.7

Reference #:

IC83184

Modified date:

2012-11-28

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