title: What makes hot deployment a "hard problem"?
body: <p>At work, we've been having a problem with "<a href="http://www.jroller.com/agileanswers/entry/preventing_java_s_java_lang" rel="noreferrer">PermGen out of memory</a>" exceptions, with the team lead deciding it was a bug in the JVM - something related to hot-deployment of code. Without explaining many details, he pointed out that hot deployment is a "hard problem", so hard that even .NET doesn't do it yet.</p>
  
  <p>I found a lot of articles explaining hot deployment from the bird's-eye-view, but always lacking technical details. Could anyone point me to a technical explanation, and explain why hot deployment is "a hard problem"?</p>