At 66677d3, the performance of a minimal Rack application decreased from 77,000 reqs / sec. to 68,000 reqs / sec. due to the overhead of context switch (between fibers).

With commit e2f6d9e, it is now possible to write a mruby handler like below that issues HTTP requests. And the HTTP request issued by http_request method does not block the event loop of H2O.

mruby.handler: |
  Proc.new do |env|
    # return response from example.com
    http_request("GET", "http://example.com/#{env["PATH_INFO"]}")
  end

(note: snippet update to reflect latest commit)

ToDo:

• accept headers passed to http_request method
• pass request body to mruby handler in a way that can be passed effectively to the http_request method (relates to mruby: support env[rack.input] #515)
• separate timeout for http_request?
  • at the moment, the value is fixed to that defined using proxy.timeout.io
• find a way to handle 399 response returned after async calls
• add tests