If you have a Java application that is consuming CPU when it isn't doing anything, how do you determine what it is doing?

Question

I am calling a vendor\'s Java API, and on some servers it appears that the JVM goes into a low priority polling loop after logging into the API (CPU at 100% usage). The sam

Answer 1

If JConsole can't be used you can

• press CTRL+BREAK under Windows
• send kill -3 <process id> under Linux

to get a full Thread Dump. This doesn't affect performance and can always be run in production.

Answer 2

For completeness sake: even though my company more or less standardizes on Eclipse we use Netbeans (6 and up) with its included, free profiler on a daily basis. It works better than the Eclipse TPTP plugin (last checked 3 months ago) and for us it removes any need for a commercial profiler such as JProfiler, which is excellent, but fast becoming unnecessary.