I’m currently monitoring a Java application with jconsole. The memory tab lets you choose between: Heap Memory Usage Non-Heap Memory Usage Memory Pool “Eden Space” Memory Pool “Survivor Space” Memory Pool “Tenured Gen” Memory Pool “Code Cache” Memory Pool “Perm Gen” What is the difference between them ?
Assuming that you're using the Sun JDK, the best answer will be found in their documentation: Tuning Garbage Collection (JDK 1.5) and Garbage Collection FAQ (JDK 1.4)