title: Perform GC and CPU monitoring is disabled in VisualVM
body: <p>I am monitoring Java web application running on tomcat server on localhost using VisualVM tool.
  The problem I am facing is the perform GC button in sampler is disabled. Why I want explicit Perform GC is that when I am creating heap dump without performing GC it is showing all of the objects created since application run including the objects which are dereferenced and ready for garbage collection. Creating a confusion which object is still alive and which is ready for GC.</p>
  
  <p>I am attaching the snapshot of the same.</p>
  
  <p>For any other needed information please comment. 
  Thank you in advance.
  <a href="https://i.stack.imgur.com/5WXJl.png" rel="nofollow noreferrer">VisualVM Sampling</a></p>