I would like to find out what is the total heap size that is in use at a certain time by a Java process and I have to use jmap
.
The output of jmap -heap <pid>
gives me something like this:
Attaching to process ID 2899, please wait... Debugger attached successfully. Server compiler detected. JVM version is 14.2-b01 using thread-local object allocation. Parallel GC with 2 thread(s) Heap Configuration: MinHeapFreeRatio = 40 MaxHeapFreeRatio = 70 MaxHeapSize = 1258291200 (1200.0MB) NewSize = 1048576 (1.0MB) MaxNewSize = 4294901760 (4095.9375MB) OldSize = 4194304 (4.0MB) NewRatio = 8 SurvivorRatio = 8 PermSize = 16777216 (16.0MB) MaxPermSize = 67108864 (64.0MB) Heap Usage: PS Young Generation Eden Space: capacity = 119013376 (113.5MB) used = 117277608 (111.84464263916016MB) free = 1735768 (1.6553573608398438MB) 98.54153536489882% used From Space: capacity = 131072 (0.125MB) used = 81920 (0.078125MB) free = 49152 (0.046875MB) 62.5% used To Space: capacity = 131072 (0.125MB) used = 0 (0.0MB) free = 131072 (0.125MB) 0.0% used PS Old Generation capacity = 954466304 (910.25MB) used = 80791792 (77.04905700683594MB) free = 873674512 (833.2009429931641MB) 8.46460390077846% used PS Perm Generation capacity = 57671680 (55.0MB) used = 41699008 (39.76727294921875MB) free = 15972672 (15.23272705078125MB) 72.30413263494319% used
Can I use a formula for these values to find out total memory used?
Other suggestions on how can I find this out on Linux are welcome but jmap
is preferred over them.
Thanks
jmap -heap:format=b <pid>
and parsing the heap dump file with Memory Analyzing Tool from Eclipse gives me a total usage of 22Mb. I can't find a way to obtain the same total value... – Lardy