title: Diagnosing node crush in JMS communication through ActiveMQ
body: <p>I have java applications (nodes) that communicate via JMS (ActiveMQ + Camel). I have situation like this one:</p>
  
  <p>1.) Node_1 put message in queue
  2.) message is in queue for a while, because Node_2 is busy
  3.) Node_2 take message whenever is ready</p>
  
  <p>Each node and ActiveMQ are in separable machines. Let's say that Node_2 became inaccessible (maybe machine just crushed). <strong>What is the best way to inform Node_1 that Node_2 is inaccessible?</strong> </p>
  
  <p>I'm not jet fully familiar with those technologies. I have noticed that there is some kind of inactivity monitor, and I thought that it could be a good tool to use. Unfortunately, I do not know and can't find if I can use it to run a custom action in ActiveMQ side. <strong>Can I run a custom action in ActiveMQ if Node_2 is inaccessible?</strong></p>