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PH10577: PERFORMANCE OPTIMIZATION OF ASYNCHRONOUS CROSS-INVALIDATION EXPLOITATION

A fix is available

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APAR status

  • Closed as new function.

Error description

  • Performance optimization of asynchronous cross-invalidation
    exploitation (Async XI)
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * All Db2 12 for z/OS data sharing users.                      *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * APAR PH10577 enables the use of                              *
    * Coupling Facility (CF) asynchronous                          *
    * cross-invalidation (XI).                                     *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Apply corrective PTF when available                          *
    ****************************************************************
    In APAR PH05193, Db2 provided exploitation of the Coupling
    Facility (CF) asynchronous cross-invalidation (XI) feature
    for cross invalidations of data pages when the table space
    is not using row-level locking and invalidation is done
    when writing updated pages during commit.
    
    Db2's use of asynchronous CF XI was initially disabled when
    APAR PH05193 was shipped.
    

Problem conclusion

Temporary fix

Comments

  • In this APAR, Db2 enables the use of asynchronous CF XI and
    delivers the performance optimization of asynchronous CF XI
    exploitation implemented via APAR PH05193.
    
    Db2 implements a threshold for how many pages needed to be
    writing at a time before using asynchronous XI.
    
    Db2 allows the use of asynchronous XI for deferred writes
    as well as force-at-commit writes, and also allows the use
    of asynchronous XI when a page P-lock is held.
    
    The dimension of various page lists used during GBP writes
    is tweaked in order to be more compatible with one another.
    
    The force-at-commit page lists are kept for the same object
    together on the chain in order to keep the writes together.
    
    Note that Db2 does not allow the use of asynchronous XI for
    cross invalidations of 32K pages.
    

APAR Information

  • APAR number

    PH10577

  • Reported component name

    DB2 OS/390 & Z/

  • Reported component ID

    5740XYR00

  • Reported release

    C10

  • Status

    CLOSED UR1

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2019-04-03

  • Closed date

    2019-05-01

  • Last modified date

    2019-06-03

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

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

    UI62802

Modules/Macros

  • DSNB5SCM DSNB1GC1 DSNB1TPL DSNB1PMI DSNB5SC1 DSNB5CMX DSNB1RBC
    DSNB1DAL DSNB1CSX DSNB1DCM DSNB1CNE DSNB1RWI DSNB1PCP DSNB5SC2
    DSNB1SWS DSNB1CPP DSNB1AGB DSNB1CLT DSNB1ULT DSNB1CMU
    

Fix information

  • Fixed component name

    DB2 OS/390 & Z/

  • Fixed component ID

    5740XYR00

Applicable component levels

  • RC10 PSY UI62802

       UP19/05/16 P F905

Fix is available

  • Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.

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Document Information

Modified date:
03 June 2019