HEAP DUMP too big to open in Eclipse MAT

Question

I have a heap dump that is causing out of memory exception for my program, the size for the heap dump is 12GB because of which I am unable to load it in my MAT analyser, what are the alternatives I can try, or is there a way I can upload the heap dump to MAT.

Answer 1

If you have a server with good amount of free memory, then you can try to run MAT on that server after increasing it's heap size. The more memory you allocate to MAT, the faster it will operate.

In MemoryAnalyzer.ini file you'll get -Xmx option to change max heap size of MAT. MAT documentation also suggests to disable GC overhead limit.

-vmargs
-Xmx18g
-XX:-UseGCOverheadLimit

You can also try to use ParseHeapDump script to run MAT in "headless" mode. There are other tools like visualvm but you need to allocate it almost similar amount of memory to process this large heap dump.

As far as I know, there is no online version of MAT. There is other online option is heaphero but please be careful while uploading heap dump to third party sites as heap dumps may contain sensitive information.

Answer 2

It would be better if you analyze the heap dump in to the remote Unix server. If it has enough RAM (Available RAM should be > heap-dump-size ).

I was unable to parse the heap dump ( > 8 GB) Using MAT GUI in local system ( having RAM < 16GB).

Hence go for headless MAT option. Please check https://stackoverflow.com/a/76298700/5140851