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Distributed Caching Using the JCACHE API and ehcache, Including a Case Study on Wotif.com (A nice caching overview article)
http://developers.sun.com/learning/javaoneonline/2007/pdf/TS-6175.pdf
The Apache Tomcat 5.5 Servlet/JSP Container - Monitoring and Managing Tomcat
http://tomcat.apache.org/tomcat-5.5-doc/monitoring.html
Monitoring and Management Using JMX
http://java.sun.com/j2se/1.5.0/docs/guide/management/agent.html