title: HTTP-Long Polling keep-alive and handshakes
body: <p>I'm doing a test where I examine how much HTTP-long polling compared to Websockets is affecting the battery performance on my iPhone. Basically what I have is a Node.js with express server that sends out a random string every 0.5 or 10th second to the iPhone. I've inspected the messages in Chrome and I can see the keep-alive header is present. I know keep-alive is a default feature since HTTP/1.1. From what I've understood the TCP-connection will be held open and can be used for pipelining, and this is certainly the case when I'm sending out pings from the server every 0.5 seconds. But when I send out every 10 seconds, will the connection be closed during that time?</p>
  
  <ol>
  <li><p>How do I know how long the connection is open? This seems to be a crucial part to have in mind when doing the tests. </p></li>
  <li><p>Will the HTTP-handshake still be made when the TCP-connection is open?</p></li>
  </ol>