title: how to collect jmeter runtime measurements and create a graph
body: <p>I'm looking for a way to run a jmeter from command line, 
  collect the data from Summary Report to some file (say every x seconds) during the execution. 
  Then load the saved file to the jmeter to see the limeline graphs of the collected metrics.</p>
  
  <p>How can I do such thing?</p>