PQ70308: PERFORMANCE ISSUES WHEN MANY ENTITY BEANS OF THE SAME TYPE ARE ACTIVATED.

 A fix may be available

Obtain the fix for this APAR



APAR status
Closed as program error.

Error description
Performance issues when many Entity beans of the same type are
activated.
Local fix Problem summary
****************************************************************
* USERS AFFECTED: All users of WebSphere Application Server    *
*                 V4.0.1 for z/OS and OS/390                   *
****************************************************************
* PROBLEM DESCRIPTION: Customer reported peformance issues     *
*                      when accessing many instances of the    *
*                      the same bean type.                     *
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* RECOMMENDATION:                                              *
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APAR PQ70308 addesses the following performance issues:
1) BeanIDs are inefficiently tested from start to end. When
   comparing different instances of the same beantype the unique
   information will be contained at the end of the bean id.
2) The Wrapper Cache makes a redundant lookup during insertion.
Problem conclusion
Support has been modified to address the performance issues
documented in APAR PQ70308.

APAR PQ70308 requires a change to documentation.

This APAR requires changes to documentation.

The following WebSphere Application Server V4.0.1 for z/OS
and OS/390 publications will be changed:

   Operations and Administration (GA22-7835-06)
   Assembling J2EE Applications (SA22-7836-05)

To access the latest online documentation, go to the product
library page at:

www.ibm.com/software/webservers/appserv/zos_os390/

WebSphere Application Server V4.0.1 for z/OS and OS/390
Operations and Administration (GA22-7835-06)
will be changed as follows:

Chapter 9. WebSphere for z/OS performance tuning
           guidelines
  Subtopic "Component management"
  Section "Java virtual machine properties file
          (jvm.properties):"

Add the following bullet on page 114:

  o  com.ibm.ejs.EJBCache.size --  provides the
     ability to tailor the EJB cache size. The impact
     on performance is workload dependent, and
     knowledge of entity bean usage is important in
     calculating the size of the EJB cache.

     - com.ibm.ejs.EJBCache.size=INT

     Note: The default value is 251. The value
           should be a prime number greater than 1.
           The EJB cache size should correspond to
           entity Bean usage.

WebSphere Application Server V4.0.1 for z/OS and OS/390
Assembling J2EE Applications (SA22-7836-05)
will be changed as follows:

"Appendix A. Environment and JVM properties files"
Topic "JVM properties and properties files"
"Table 24. Where to use JVM properties" will be updated with
   the new entry for property "com.ibm.ejs.EJBCache.size=251"
   which is optional for only J2EE servers.

"Appendix A. Environment and JVM properties files"
Topic "Properties descriptions" on page 303 will be updated
  with the following new property description:

  com.ibm.ejs.EJBCache.size=number
    Sets the size of the Enterprise bean (EJB) cache.

    Recommendation: Calculate the cache size based on the
    workload of this J2EE server.  The number that you
    specify for the size should correspond to the number of
    activated entity beans in the J2EE server.

    Default: 251

APAR PQ70308 is associated with SERVICE LEVEL W401501 of
WebSphere Application Server V4.0.1 for z/OS and OS/390.
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++HOLD for DOC

APAR PQ70308 requires a change to documentation.

This APAR requires changes to documentation.

The following WebSphere Application Server V4.0.1 for z/OS
and OS/390 publications will be changed:

   Operations and Administration (GA22-7835-06)
   Assembling J2EE Applications (SA22-7836-05)

To access the latest online documentation, go to the product
library page at:

www.ibm.com/software/webservers/appserv/zos_os390/

WebSphere Application Server V4.0.1 for z/OS and OS/390
Operations and Administration (GA22-7835-06)
will be changed as follows:

Chapter 9. WebSphere for z/OS performance tuning
           guidelines
  Subtopic "Component management"
  Section "Java virtual machine properties file
          (jvm.properties):"

Add the following bullet on page 114:

  o  com.ibm.ejs.EJBCache.size --  provides the
     ability to tailor the EJB cache size. The impact
     on performance is workload dependent, and
     knowledge of entity bean usage is important in
     calculating the size of the EJB cache.

     - com.ibm.ejs.EJBCache.size=INT

     Note: The default value is 251. The value
           should be a prime number greater than 1.
           The EJB cache size should correspond to
           entity Bean usage.

WebSphere Application Server V4.0.1 for z/OS and OS/390
Assembling J2EE Applications (SA22-7836-05)
will be changed as follows:

"Appendix A. Environment and JVM properties files"
Topic "JVM properties and properties files"
"Table 24. Where to use JVM properties" will be updated with
   the new entry for property "com.ibm.ejs.EJBCache.size=251"
   which is optional for only J2EE servers.

"Appendix A. Environment and JVM properties files"
Topic "Properties descriptions" on page 303 will be updated
  with the following new property description:

  com.ibm.ejs.EJBCache.size=number
    Sets the size of the Enterprise bean (EJB) cache.

    Recommendation: Calculate the cache size based on the
    workload of this J2EE server.  The number that you
    specify for the size should correspond to the number of
    activated entity beans in the J2EE server.

    Default: 251
Temporary fix Comments
APAR information
APAR number PQ70308
Reported component name WASKBASE
Reported component ID 5655A9801
Reported release 401
Status CLOSED PER
PE NoPE
HIPER NoHIPER
Submitted date 2003-01-27
Closed date 2003-03-05
Last modified date 2003-04-03

APAR is sysrouted FROM one or more of the following:

APAR is sysrouted TO one or more of the following:

Modules/Macros
BBOUBINF          

Fix information
Fixed component name WASKBASE
Fixed component ID 5655A9801

Applicable component levels
R401 PSY UQ74747    UP03/03/12 P F303

  Fix is available
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Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server for z/OS
Operating system(s):
Software version: 401
Software edition:
Reference #: PQ70308
IBM Group: Software Group
Modified date: Apr 3, 2003