title: Tool for analyzing large Java heap dumps
body: <p>I have a HotSpot JVM heap dump that I would like to analyze. The VM ran with <code>-Xmx31g</code>, and the heap dump file is 48 GB large.</p>
  
  <ul>
  <li>I won't even try <code>jhat</code>, as it requires about five times the heap memory (that would be 240 GB in my case) and is awfully slow.</li>
  <li>Eclipse MAT crashes with an <code>ArrayIndexOutOfBoundsException</code> after analyzing the heap dump for several hours.</li>
  </ul>
  
  <p>What other tools are available for that task? A suite of command line tools would be best, consisting of one program that transforms the heap dump into efficient data structures for analysis, combined with several other tools that work on the pre-structured data.</p>