Optimizing Java™ application performance for the Java™ virtualization agent

The performance of a Java™ application can be affected adversely when the Java™ virtualization agent is loaded into the application. For example, memory usage may increase or there might be pauses during application startup. To prevent these problems from occurring, modify performance parameters supported by the Java™ virtualization agent.

About this task

Procedure

If you observe "out of memory" errors, increase the size of the permanent generation space by modifying the size of the -XX:MaxPermSize JVM parameter of the Java™ application.
If you do not require the Java™ application to pause during start to collect recording and intercept rules from IBM® Rational® Test Control Panel, edit the invocation command line to include the greenhat.javaagent.waitForRules property as follows:
```
"%JAVA_HOME\bin\java" "-javaagent:%JAVA_AGENT%" -Dgreenhat.javaagent.waitForRules=-1 or X (milliseconds) -jar Java application name.jar
```
Setting the Dgreenhat.javaagent.waitForRules property to -1 prevents the Java™ virtualization agent from waiting for recording or routing rules from Rational® Test Control Panel. Alternatively, setting the Dgreenhat.javaagent.waitForRules property to X milliseconds causes the Java™ virtualization agent to wait X milliseconds when starting for recording or routing rules from Rational® Test Control Panel.

For example, to make the Java™ virtualization agent to wait 10 seconds when starting for recording or routing rules from Rational® Test Control Panel, edit the invocation command line as follows:
```
"%JAVA_HOME\bin\java" "-javaagent:%JAVA_AGENT%" -Dgreenhat.javaagent.waitForRules=10000 -jar Java application name.jar
```
To make the Java™ application to wait for a specific number of seconds for Rational® Integration Tester to determine how to process an intercepted message, edit the invocation command line to include the greenhat.javaagent.dispatchTimeout property as follows:
```
"%JAVA_HOME\bin\java" "-javaagent:%JAVA_AGENT%" -Dgreenhat.javaagent.dispatchTimeout=X (milliseconds) -jar Java application name.jar
```
For example, if you want the Java™ application to wait 60 seconds for Rational® Integration Tester to determine how to process an intercepted message, edit the invocation command line as follows:
```
"%JAVA_HOME\bin\java" "-javaagent:%JAVA_AGENT%" -Dgreenhat.javaagent.dispatchTimeout=60000 -jar Java application name.jar
```