eclipse memory analyzer sees small part (363,2MB) of entire heap dump (8GB)

Question

I was trying to investigate java.lang.OutOfMemoryError: GC limit exceeded which occurs at high load of our web app deployed in tomcat. Heap size was set to 8GB

Answer 1

We found a bug in MAT recently where it would only see a subset of the heap: https://bugs.eclipse.org/bugs/show_bug.cgi?id=404679#c3

The problem was that the JVM wrote a single HEAP_DUMP record that was more than 4GB and therefore the length in the header wrapped.

What version of MAT are you running? Please try a more recent build.