multithreading not working for requests to the same url

[Mathijs <bluescreen303@gmail.com>]

Hi all,


In my application, a lot of time is spent on /inbox.
However, it looks as if rack does not support handling multiple
requests to the same url simultaneously.

I used this 'demo' app:
class HelloWorld
  def call(env)
    sleep 15
    [200, {'Content-Type' => 'text/plain'}, ["Hello world!"]]
  end
end
run Helloworld.new

run with rackup demo.ru
open 3 browser tabs, enter these urls:
- http://localhost:9292/path1
- http://localhost:9292/path1
- http://localhost:9292/path2

You'll see that if you start the requests roughly at the same time,
the first path1 and path2 will complete at the same time.
The second path1 comes 15sec behind.

Passing params (localhost:9292/path1?blah=3) will
trick the app to handle the request in parallel. Also, aliasing
localhost does the trick.
So it looks as if rack does some locking per url.
I couldn't find anything though.

I tried this under REE with mongrel and webrick and under jruby with
trinidad and webrick.
They all behave the same.

Is anyone aware of this behavior? What is the cause?
Thanks,
Mathijs