title: monitoring applications, uptime, log files, etc
body: <p>How do you monitor your application in production?  logs, uptime, etc... (I would prefer an external application, free and open source)</p>
  
  <p>For example, I would like</p>
  
  <ol>
  <li>ability to send out alert if the application goes down</li>
  <li>send alert if cpu usage > than a set threshold</li>
  <li>send alert if memory usage > than a set threshold</li>
  <li>send alert for error messages</li>
  <li>must be configurable, maybe some errors send alert if occurs X times in Y time period</li>
  </ol>