In fact, analyzing the heap dump is not rocket science, many tools are available to do this. My intention was to use the IBM Support Assistant and then install the MDD4J-plugin on my laptop. All done without much hassle, so then of to analyze the actual heap dumps made available to me. Problem was that the dump-files are all about 400Mb, which it turns out my Windows XP-running laptop ain’t capable of managing. Tried to change default heap size for the tooling by following the steps I found in this post on Developerworks, but no help. I still got the “negative size” error. This was when using the 2.0.x version of MDD4J.
So, I tried to use the beta version of the 3.0.1.x version of MDD4J. I got rid of the negative size-error, just to get a new one “Capacity is less than zero”. Did a Google-search and found yet another post on Developerworks, with one reply from a guy named Thomas who is part of the MDD4J development team saying:
Hello everyone, this is Tomas, I’m a member of MDD4J development team.
I’m posting this just to confirm that in cases when MDD4J is unable to run analysis on a 32 bit platform, the right solution is to follow the instructions on how to run the analysis outside of ISA. The best combination is a 64bit Linux machine with IBM’ 1.5 JRE.
After running the analysis, you can copy the analysis directory back to your ISA’s workspace, into directory: <user home>/ibm/isa41/.metadata/.plugins/com.ibm.websphere.mdd4j.beta
Tomas
…so, just forget my Win XP and instead off to find a running Linux installation which I can use.