Studying Heap Usage in a JRockit Flight Recording

A JRockit flight recording of your application shows detailed statistics on garbage collection activity and heap contents during the recording.

As described in "Studying Heap Usage in Verbose Outputs", an increasing heap usage over time might be a sign of a memory leak in your application; for example, in the Flight Recorder, the Memory tab's Heap Contents subtab shows the amount of dark matter on the heap. Dark matter is fragmented free space on the heap, where each fragment is too small for object allocation. A small amount of dark matter is normal, but if the amount of dark matter grows over time, this is a sign of a fragmentation problem. Increasing fragmentation also increases the heap usage. If you see both increased heap usage and increased fragmentation at the same time, the problem might be in fragmentation rather than a memory leak.