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PM33176: IMPROVE CALCULATION OF SIZE OF SRQE QUEUE LIMIT FOR DEFAULT MESSAGING PROVIDER.

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APAR status

  • Closed as program error.

Error description

  • Default messaging provider experiences slowdown and eventually
    transaction timeouts and ABENDEC3/ABENDSEC3 reason 04130005.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:  All users of IBM WebSphere Application      *
    *                  Server V7.0                                 *
    ****************************************************************
    * PROBLEM DESCRIPTION: Default messaging provider              *
    *                      experiences slowdown and eventually     *
    *                      transaction timeouts and                *
    *                      ABENDEC3/ABENDSEC3 reason 04130005.     *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    The default messaging provider (Service Integration Bus)
    experiences a slowdown and eventually transaction timeouts
    that cause an Abend of the servant job. The slowdown is the
    result of the queue limit value of 15 on an internal SRQE
    queue. During higher workloads, PUTs to the queue may outpace
    GETs and once the queue limit is reached, the queue is
    temporarily write-disabled. When space is available again, the
    queue is write-enabled but may almost immediately become
    disabled again, causing a type of "thrashing" cycle.
    

Problem conclusion

  • The static value of 15 for the internal queue limit has been
    replaced with a calculated limit based on the number of
    servant threads. The number of servant threads is controlled
    by the setting of the Workload Profile (ISOLATE, IOBOUND,
    CPUBOUND, LONGWAIT, or CUSTOM). The calculated limit provides
    a more optimal value based on workload and removes an
    arbitrary restraint.
    
    It is also important to review the topic "Configuring MDB
    throttling for the default messaging provider" in the
    InfoCenter. This topic provides additional information for the
    tuning of MDB performance.
    
    APAR PM33176 requires changes to documentation.
    
    NOTE: Periodically, we refresh the documentation on our Web
    site, so the changes might have been made before you read this
    text. To access the latest on-line documentation, go to the
    product library page at:
    
    http://www.ibm.com/software/webservers/appserv/library
    
    The following changes to the z/OS version of the WebSphere
    Application Server Version 7.0 Information Center will be made
    available in May, 2011.
    
    The following information will be added to the topic
    "Application server custom properties that are unique for the
    z/OS platform":
    
    protocol_jfap_queue_limit
    Specifies the number of messages that can reside on the JFAP
    protocol message queue that is associated with a servant
    process. This queue is used to hold pending messages that are
    being sent between the servant process and the controller.
    You can specify any positive integer as the value for this
    property. However, whenever possible, you should use the
    default value 0. A value of 0 indicates that the number of
    messages that can reside in the JFAP protocol message queue is
    four times  the number of dispatch threads in the servant.
    Therefore, this value provides a calculated limit based on
    workload, and removes the arbitrary restraints imposed by
    specifying a specific value for this property.
    The number of dispatch threads in the servant is controlled by
    the ORB services Workload profile setting. See the topic "ORB
    services advanced settings on the z/OS platform" for more
    information about this setting.
    You should also review the topic "Configuring MDB throttling
    for the default messaging provider" for a description of how
    to tune message-driven beans.
    
    Data Type                             Integer
    Default                                     0
    Used by Daemon               No
    
    APAR PM33176 is currently targeted for inclusion in Service
    Level (Fix Pack) 7.0.0.17 of WebSphere Application Server V7.0.
    
    Please refer to URL:
    //www.ibm.com/support/docview.wss?rs=404&uid=swg27006970
    for Fix Pack availability.
    

Temporary fix

Comments

APAR Information

  • APAR number

    PM33176

  • Reported component name

    WEBSPHERE FOR Z

  • Reported component ID

    5655I3500

  • Reported release

    700

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2011-02-18

  • Closed date

    2011-03-01

  • Last modified date

    2011-06-02

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

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

Fix information

  • Fixed component name

    WEBSPHERE FOR Z

  • Fixed component ID

    5655I3500

Applicable component levels

  • R700 PSY UK67335

       UP11/05/19 P F105

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.



Document information

More support for: WebSphere Application Server for z/OS
General

Software version: 7.0

Reference #: PM33176

Modified date: 02 June 2011