For more information on performance tuning and troubleshooting, see the following resources:
Java Performance portal site
http://java.sun.com/javase/technologies/performance.jsp
Java Tuning Whitepaper
http://java.sun.com/performance/reference/whitepapers/tuning.html
Java Hotspot VM Options
http://java.sun.com/javase/technologies/hotspot/vmoptions.jsp
Solaris TCP Tuning Parameters
http://docs.sun.com/app/docs/doc/817-0404/6mg74vsaj?a=view
Understanding Tuning TCP
http://www.sun.com/blueprints/1205/819-5144.pdf
Tuning for Linux platforms
http://www.redbooks.ibm.com/abstracts/redp4285.html
Java 5.0 Troubleshooting and Diagnostic Guide
http://java.sun.com/j2se/1.5/pdf/jdk50_ts_guide.pdf
Troubleshooting JRE 6 Deployment
http://java.sun.com/developer/technicalArticles/javase/troubleshoot/