{"id":3113,"date":"2010-03-01T07:57:45","date_gmt":"2010-03-01T07:57:45","guid":{"rendered":""},"modified":"2026-04-18T22:54:39","modified_gmt":"2026-04-18T22:54:39","slug":"how-to-analyze-a-heap-dump","status":"publish","type":"post","link":"https:\/\/hellem.org\/wblog\/?p=3113","title":{"rendered":"How to analyze a heap dump"},"content":{"rendered":"

In fact, analyzing the heap dump<\/a> is not rocket science, many tools are available to do this. My intention was to use the IBM Support Assistant<\/a> and then install the MDD4J<\/a>-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<\/a>, but no help. I still got the “negative size” error. This was when using the 2.0.x version of MDD4J. <\/p>\n

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<\/a>, with one reply from a guy named Thomas who is part of the MDD4J development team saying:<\/p>\n

Hello everyone, this is Tomas, I’m a member of MDD4J development team.
\nI’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.
\nAfter 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<\/p>\n

Tomas<\/p><\/blockquote>\n

…so, just forget my Win XP and instead off to find a running Linux installation which I can use.<\/p>\n","protected":false},"excerpt":{"rendered":"

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 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[47],"tags":[],"class_list":["post-3113","post","type-post","status-publish","format-standard","hentry","category-work-geek"],"_links":{"self":[{"href":"https:\/\/hellem.org\/wblog\/index.php?rest_route=\/wp\/v2\/posts\/3113","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/hellem.org\/wblog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/hellem.org\/wblog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/hellem.org\/wblog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/hellem.org\/wblog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3113"}],"version-history":[{"count":1,"href":"https:\/\/hellem.org\/wblog\/index.php?rest_route=\/wp\/v2\/posts\/3113\/revisions"}],"predecessor-version":[{"id":14488,"href":"https:\/\/hellem.org\/wblog\/index.php?rest_route=\/wp\/v2\/posts\/3113\/revisions\/14488"}],"wp:attachment":[{"href":"https:\/\/hellem.org\/wblog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3113"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/hellem.org\/wblog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3113"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/hellem.org\/wblog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3113"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}