How to make async http request in rails

Question

In my rails app, I need to make a http request to 3rd party service, since http request is synchronous, sometimes it takes more than 20 seconds to get response back from them.

I just push some data to that service, I don't care about what the response will be, so I want to make the request asynchronous, so my code will continue execution and not been blocked.

How could I do it in ruby?

Answer 1

You need to use Event Machine and Fibers in ruby.

Github: em-http-request

Answer 2

I need to make a http request...so my code will continue execution and not been blocked.

def some_action
  Thread.new do
    uri = URI('http://localhost:4567/do_stuff')
    Net::HTTP.post_form(uri, 'x' => '1', 'y' => '2')
  end

  puts "****Execution continues here--before the response is received."
end

Here's a sinatra app you can use to test it:

1) $ gem install sinatra

2)

#my_sinatra_app.rb

require 'sinatra'

post '/do_stuff' do
  puts "received: #{params}" #Check the sinatra server window for the output.
  sleep 20  #Do some time consuming task.

  puts "Sending response..."
  "The result was: 30"   #The response(which the rails app ignores).
end

output:

$ ruby my_sinatra_app.rb
== Sinatra (v1.4.6) has taken the stage on 4567 for development with backup from Thin
Thin web server (v1.6.4 codename Gob Bluth)
Maximum connections set to 1024
Listening on localhost:4567, CTRL+C to stop

received: {"x"=>"1", "y"=>"2"}
<20 second delay>
Sending response...

127.0.0.1 - - [11/Nov/2015:12:54:53 -0400] "POST /do_stuff HTTP/1.1" 200 18 20.0032

When you navigate to some_action() in your rails app, the rails server window will immediately output ****Execution continues here--before the response is received., and the sinatra server window will immediately output the params hash, which contains the data sent in the post request. Then after a 20 second delay the sinatra server window will output Sending response....