I recently wrote an article "Monitoring and Managing Java SE 6 Platform Applications". Alan, Sundar, Kelly and I have blogged about various JDK 6 enhancements in the monitoring, management, and diagnosability area.

This article gives you an overview of the monitoring and management capabilities out of the box in JDK 6 and presents a short course how to diagnose several common Java SE problems including memory leaks, deadlocks, and synchronization issues with the use of the JDK tools.