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Question |
This document explains why WebSphere Application Server
Version 5 uses more disk space and more memory than previous versions of
WebSphere. |
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Answer |
WebSphere Application Server and the JDK have been
enhanced to improve their usability and effectiveness; therefore, the disk
space and memory required to run the WebSphere Application Server
processes have increased.
Summary of Changes
While balancing usability, function and performance, these are the most
significant changes that affect required disk space and memory:
- Elimination of the Administrative Console as a Java thick
client moved function into the server process.
- Elimination of a database as the repository moved function
into the server process. The WebSphere repository is now maintained in
memory by the NodeAgent process.
- Distribution of v3.x and v4.x administrative server
functions improve fault tolerance and application performance. Each
application server now includes a security server and a name service.
- Addition of Java 2 security support.
- Inclusion of EJB 2.0 standard support, which includes
support for Message Driven Beans and the optional installation of an
embedded messaging provider.
- Inclusion of EJB deploy, leveraging the standards-based
Eclipse framework.
- Enhancement of ORB technology to support new standards
(for example, CSIv2), as well as prior standards for version
interoperability; for example, Secure Association Service.
- Implementation of the JMX standard as the administration
interface, which moved an administration process into each application
server. Each application server can now be directly managed, in addition
to centrally managed (in WebSphere Application Server Network
Deployment).
- Addition of installation verification classes that
interface with the IVT tool.
- Inclusion of Embedded Messaging to provide session
persistence without a database.
Characteristics of change in disk usage:
- 48% more class files
- 70% more JAR files
- 28% more disk space used (without installation of Embedded
Messaging)
Characteristics of change in memory usage:
- 21% more classes loaded during startup
- 40% more live objects created during startup
- Note: startup time was improved through performance tuning
in fix pack 2.
Aside from these specific changes, WebSphere Development endeavors to keep
the memory usage consistent from release to release.
Minimizing Disk Space and Memory Used
You can minimize disk space and memory used in a specific configuration by
selecting only the WebSphere Application Server components required to
support deployed applications.
For example, Samples and Embedded Messaging are components frequently
omitted from production configurations.
Components can be installed independently into a WebSphere Application
Server configuration when they are needed.
More Information About Performance Tuning
- Go to the WebSphere Application Server Support Page: http://www-306.ibm.com/software/webservers/appserv/was/support/
- In the "InfoCenter" section, select "Product Information."
- Select the appropriate Information Center for your needs.
- Click Performance on the Information Center main page.
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Cross Reference information |
Segment |
Product |
Component |
Platform |
Version |
Edition |
Application Servers |
Runtimes for Java Technology |
Java SDK |
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Historical Number |
PMR 39063
278 |
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