title: How scalable are server-sent events in Rails?
body: <p>I'm planning on writing a Rails app where multiple users are going to have updated information pushed to them using server-sent events with ActionController::Live and Puma.  I've already written a test app and it seems to work very well.  For what I'm doing, SSEs make more sense than WebSockets as most of the users are just 'listening' and SSEs are much simpler than setting up websockets-rails which also depends on Faye(in which case I'd just write my own code on top of Faye).  </p>
  
  <p>What I want to know is just how scalable are server-sent events in Rails?  This is under the premise that I'll be using Puma, which creates a new thread for every user who is connected to the EventSource.  Potentially, this app aims towards the possibility of having hundreds of thousands of users connected at once, but by Puma's default thread limit is 16.  Is there any reason why I can't change the thread limit to 200,000?</p>