title: HTTP POST: content-length header required?
body: <p>I'm currently trying to optimize http-based data transfer between several applications.
  Our current approach, downloading first and then creating the post-request, obviously add extra IO/memory load and latencies, which I'd like to circumvent.</p>
  
  <p>The core question of all:</p>
  
  <p>Is it required to send a "Content-Length" header in HTTP POST requests?
  IIRC, HTTP 2616 declares that it's optional, but I'm not sure how applications actually behave at this point.</p>