gistfile1.txt

class ConcurrencyTestApp < Sinatra::Base

  get "/asynch_test" do
    Net::HTTP.get(URI("http://localhost:5000/long_call"))
    "Hello world"
  end

  get "/long_call" do
    sleep 4
  end
end

gistfile2.txt

get "/asynch_test" do    
    Celluloid.defer do
      response = Net::HTTP.get(URI("http://localhost:5000/long_call"))
    end
  "Hello world"
end



Celluloid::Task::TerminatedError

gistfile3.txt

require 'sinatra'
require 'celluloid/io'
require 'http'

class HttpFetcher
  include Celluloid::IO

  def fetch(url)
    HTTP.get(url, socket_class: Celluloid::IO::TCPSocket).response
  end
end

class ConcurrencyTestApp < Sinatra::Base

  get "/asynch_test" do
    fetcher = HttpFetcher.new

    response = fetcher.fetch('http://localhost:5001/long_call')

    "Hello world"
  end

  # This is being run on another server
  get "/long_call" do
    sleep 4
    'woow'
  end
end

@Nerian, thanks! it's good to have use cases to test with! :)

So i tried this: https://gist.github.com/kenichi/9944480

and it seems to work... lemme know what you find!