Simple SSE example -- works fine locally, connections never close on Heroku. Running at http://obscure-depths-3413.herokuapp.com/

app.rb

require 'sinatra/base'

class MyApp < Sinatra::Base

  set :path, '/tmp'
  set :environment, 'production'

  def initialize
    @connections = []

    EM::next_tick do
      EM::add_periodic_timer(1) do
        @connections.each do |out|
          out << "connections: " << @connections.count << "\n"
        end
        puts "*** connections: #{@connections.count}"
      end
    end

  end

  get '/' do
    stream(:keep_open) do |out|
      @connections << out
      puts "Stream opened from #{request.ip} (now #{@connections.size} open)"

      out.callback do
        @connections.delete(out)
        puts "Stream closed from #{request.ip} (now #{@connections.size} open)"
      end
    end
  end

end

config.ru

require "./app"

$stdout.sync = true
run MyApp

Gemfile

source "https://rubygems.org"
ruby '1.9.3'

gem 'sinatra'
gem 'thin'
gem 'foreman'

Gemfile.lock

GEM
  remote: https://rubygems.org/
  specs:
    daemons (1.1.9)
    dotenv (0.8.0)
    eventmachine (1.0.3)
    foreman (0.63.0)
      dotenv (>= 0.7)
      thor (>= 0.13.6)
    rack (1.5.2)
    rack-protection (1.5.0)
      rack
    sinatra (1.4.3)
      rack (~> 1.4)
      rack-protection (~> 1.4)
      tilt (~> 1.3, >= 1.3.4)
    thin (1.5.1)
      daemons (>= 1.0.9)
      eventmachine (>= 0.12.6)
      rack (>= 1.0.0)
    thor (0.18.1)
    tilt (1.4.1)

PLATFORMS
  ruby

DEPENDENCIES
  foreman
  sinatra
  thin

Procfile

web: bundle exec thin -R config.ru start -p $PORT

Ever figure out a solution to this?