JRockit full memory dump

Question

I suspect that my application have a memory leak. I have GC logs and when I look at them I see that memory usage is about 9-10GB. Then I try to dump memory to the file, the file size is about 5GB.

The question is why dump has not got 9GB in size, but only 5GB? How can I force jrcmd to dump full memory?

Command that I use:

jrcmd 11906 hprofdump filename=/path_to_dump/dump.hprof

JVM:

Java(TM) Platform, Standard Edition for Business (build 1.5.0_28-b04)
Oracle JRockit(R) (build R28.1.3-11-141760-1.5.0_28-20110301-1432-linux-x86_64, compiled mode)

Update:

The problem is that due to GC logs memory is never freed up to level that is below 9GB. JDK tool truncated dump to 5GB. Why?

Answer 1

I assume JRockit behaves similar to HotSpot: if your live data set is only 5 GB then the dump also only 5 GB. I assume only 5 GB of your 9-10 are live.

Answer 2

What does your GC log look like?

BTW, have you tried the JRockit Mission Control tool called Memleak? It can be useful for finding memory leaks.