PM81785: READ-AHEAD

A fix is available

Subscribe

You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • Read-ahead improvements.
    *
    Additional keywords:
    QRep
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED: All users of WebSphere MQ for z/OS Version 7 *
    *                 Release 1.                                   *
    ****************************************************************
    * PROBLEM DESCRIPTION: InfoSphere Data Replication, Q          *
    *                      Replication slows down when MQ transmit *
    *                      queue or Q Replication apply queue      *
    *                      exceed buffer pool capacity and size of *
    *                      MQ messages is greater than 30kB.       *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    New read ahead function is provided to parallelize the disk read
    operations required to pre-stage data for large messages from
    the pageset into the bufferpool for MQGET operations.
    

Problem conclusion

  • Users of Q Replication can enable the large message read ahead
    function for the queue managers hosting Q Replication
    transmission and apply queues with the MQSC commands:
     RECOVER QMGR(TUNE READAHEAD ON)
     RECOVER QMGR(TUNE RAHGET    ON)
    
    The function can be activated dynamically by entering at a
    console, or, added to the queue manager configuration by adding
    to a file processed in the CSQINP2 concatenation during queue
    manager start up.
    
    Additionally, non-serialized pageset access should be enabled
    by rebuilding ZPARM with an additional service switch activated
    and restarting queue manager. Contact IBM support for details
    on setting the Service parameter.
    100Y
    CSQIDUSE
    CSQIMGE9
    CSQIRAHP
    CSQIRECP
    CSQPMTRM
    CSQP1CON
    CSQP1DWP
    CSQP1INI
    CSQP1RAH
    

Temporary fix

Comments

APAR Information

  • APAR number

    PM81785

  • Reported component name

    WMQ Z/OS V7

  • Reported component ID

    5655R3600

  • Reported release

    100

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    YesSpecatt / New Function

  • Submitted date

    2013-01-31

  • Closed date

    2013-02-06

  • Last modified date

    2013-09-25

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

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

    UK91439

Modules/Macros

  • CSQIDUSE CSQIMGE9 CSQIRAHP CSQIRECP CSQPMTRM
    CSQP1CON CSQP1DWP CSQP1INI CSQP1RAH
    

Fix information

  • Fixed component name

    WMQ Z/OS V7

  • Fixed component ID

    5655R3600

Applicable component levels

  • R100 PSY UK91439

       UP13/02/20 P F302

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.



Rate this page:

(0 users)Average rating

Document information


More support for:

z/OS family

Software version:

7.1

Reference #:

PM81785

Modified date:

2013-09-25

Translate my page

Machine Translation

Content navigation