title: Do SSE / long-polling connections tie up Unicorn processes on Heroku?
body: <p>We've got a Rails app running on Unicorn/Heroku, with Unicorn configured to handle 3 concurrent worker processes. </p>
  
  <p>We've also got delayed job set up, to asynchronously handle some long-running file processing tasks that get triggered by a client request. </p>
  
  <p>We want to update the client when the task completes. We could do this with traditional polling, but are looking into using the new <a href="http://www.eventsourcehq.com/" rel="nofollow">EventSource HQ</a> Heroku add-on in order increase responsiveness and reduce the overhead of unnecessary HTTP polling requests. </p>
  
  <p>EventSource HQ uses a mix of SSE and long-polling to ensure cross-browser compatibility. What I'm trying to figure out is if the connection that gets opened up by EventSource HQ ties up a Unicorn worker process for the lifetime of the connection? In other words, if I have 3 concurrent long-running tasks processing through EventSource HQ connections, is my web dyno unable to receive new requests?</p>