Heapdump

For IBM® JVMs, generate a heapdump and use the IBM Memory Dump Diagnostic tool to identify the memory leak.

We have found this tool to be easy to use and easy to identify memory leaks. The IBM JVM automatically generates the heapdump when it runs into an OutOfMemory exception. You can also request a heapdump using a kill -3 by first setting the following environment variables:

   IBM_HEAPDUMP=true
   IBM_HEAPDUMP_OUTOFMEMORY=true
   IBM_HEAPDUMPDIR=<directory to store the heap dumps>

The IBM Memory Dump Diagnostic is an excellent tool for analyzing the heapdump. You can download the Memory Dump Diagnostic from IBM developerWorks.

You can read up on IBM heapdumps (and a lot more) in the IBM JDK 5.0/6.0 Diagnostic Guides (see IBM Developer Kit and Runtime Environment, Java™ Technology Edition, Diagnostic Guide, Version 5.0, SC34-6650).