title: Analyse MongoDB's diagnostic.data files
body: <p>My MongoDB crashed and I am trying to understand why. On Ubuntu MongoDB produces files in <code>/var/lib/mongodb/diagnostic.data</code>. Those files, e.g. <code>metrics.2016-03-08T17-15-01Z0</code>, are binary files.</p>
  
  <p>What tool should I use to analyse MongoDB diagnostic files? What data do the diagnostic files have?</p>