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Tuning the Java Runtime System
This chapter discusses the following topics:
■
“Java Virtual Machine Settings” on page 83
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“Managing Memory and Garbage Collection” on page 84
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“Further Information” on page 91
Java Virtual Machine Settings
J2SE 5.0 provides two implementations of the HotSpot Java virtual machine (JVM):
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The client VM is tuned for reducing start-up time and memory footprint. Invoke it by using
the -client JVM command-line option.
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The server VM is designed for maximum program execution speed. Invoke it by using the
-server JVM command-line option.
By default, the Application Server uses the JVM setting appropriate to the purpose:
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Developer Prole, targeted at application developers, uses the -client JVM ag to optimize
startup performance and conserve memory resources.
■
Enterprise Prole, targeted at production deployments, uses the default JVM startup mode.
By default, Application Server uses the client Hotspot VM. However, if a server VM is
needed, it can be specied by creating a <jvm-option> named “-server.”
You can override the default by changing the JVM settings in the Admin Console under
Congurations > cong-name > JVM Settings (JVM Options).
For more information on server-class machine detection in J2SE 5.0, see
Server-Class Machine
Detection .
For more information on JVMs, see
JavaTM Virtual Machines.
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