about-ruby-concurrent-requests.md

Web server comparison experiment: threaded Ruby vs. Node.js

Since a few weeks I’m working on a Node.js project at my day work, and I kind of loved the idea of the event loop, and then, because I just got off a Rails project, was wondering why wouldn’t that be possible with Ruby?

Googled a couple of evenings to find how Node.js manages to serve multiple requests on the same thread, and how its IO works. Then did the same for Ruby, read a bit about GIL, and found that in the end, there is not that much of a difference between what you can get from a threaded Ruby server and Node.js.

Played a bit with hello worlds and ended up with similar results from the speed and concurency standpoint: max 2 concurent requests on my 2CPU laptop.

For Ruby I spawn a separated Thread for every request. And from what I could google, Node.js uses a thread pool to handle the IO and one single other to run JS, which is kind of similar as far as I can understand these things. Now, I’ve tried hello world Rails and Sinatra projects, and couldn’t get any concurrency: requests were basically serialized.

So here is what ab -n 1000 -c 10 http://127.0.0.1:2345/ have shown me. I’ve run every one of the tests a few times, and the results jump around but are basically pretty close.

Now, the question I don’t have answered yet is: is this approach used somewhere in Ruby web servers?

server.js

var http = require('http'),
    request = require('request');

http.createServer(function (req, res) {
  res.writeHead(200, {'Content-Type': 'text/plain'});
  res.end('hello world');
}).listen(1337, '127.0.0.1');

console.log('Server running at http://127.0.0.1:1337/');

server.js.log

    ~/tmp/node ⌘  ab -n 2000 -c 10 http://127.0.0.1:1337/
This is ApacheBench, Version 2.3 <$Revision: 655654 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking 127.0.0.1 (be patient)
Completed 200 requests
Completed 400 requests
Completed 600 requests
Completed 800 requests
Completed 1000 requests
Completed 1200 requests
Completed 1400 requests
Completed 1600 requests
Completed 1800 requests
Completed 2000 requests
Finished 2000 requests


Server Software:        
Server Hostname:        127.0.0.1
Server Port:            1337

Document Path:          /
Document Length:        11 bytes

Concurrency Level:      10
Time taken for tests:   0.496 seconds
Complete requests:      2000
Failed requests:        0
Write errors:           0
Total transferred:      224000 bytes
HTML transferred:       22000 bytes
Requests per second:    4036.12 [#/sec] (mean)
Time per request:       2.478 [ms] (mean)
Time per request:       0.248 [ms] (mean, across all concurrent requests)
Transfer rate:          441.45 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    0   0.1      0       1
Processing:     1    2   0.6      2       7
Waiting:        1    2   0.6      2       7
Total:          1    2   0.5      2       7

Percentage of the requests served within a certain time (ms)
  50%      2
  66%      2
  75%      3
  80%      3
  90%      3
  95%      3
  98%      4
  99%      5
 100%      7 (longest request)
    ~/tmp/node ⌘  

server.rb

require 'socket'
require 'net/http'

server = TCPServer.new('localhost', 2345)

Thread.abort_on_exception = true

def respond(socket)
  request = socket.gets
  STDERR.puts request

  Thread.new do
    response = 'hello world'
    socket.print "HTTP/1.1 200 OK\r\n" +
                 "Content-Type: text/plain\r\n" +
                 "Content-Length: #{response.bytesize}\r\n" +
                 "Connection: close\r\n\r\n#{response}"
    socket.close
  end
end

loop do
  respond server.accept
end

server.rb.log

    ~/tmp/ruby ⌘  ab -n 2000 -c 10 http://127.0.0.1:2345/
This is ApacheBench, Version 2.3 <$Revision: 655654 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking 127.0.0.1 (be patient)
Completed 200 requests
Completed 400 requests
Completed 600 requests
Completed 800 requests
Completed 1000 requests
Completed 1200 requests
Completed 1400 requests
Completed 1600 requests
Completed 1800 requests
Completed 2000 requests
Finished 2000 requests


Server Software:        
Server Hostname:        127.0.0.1
Server Port:            2345

Document Path:          /
Document Length:        11 bytes

Concurrency Level:      10
Time taken for tests:   0.473 seconds
Complete requests:      2000
Failed requests:        0
Write errors:           0
Total transferred:      190000 bytes
HTML transferred:       22000 bytes
Requests per second:    4228.35 [#/sec] (mean)
Time per request:       2.365 [ms] (mean)
Time per request:       0.236 [ms] (mean, across all concurrent requests)
Transfer rate:          392.28 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    0   0.2      0       2
Processing:     1    2   1.2      2      13
Waiting:        0    2   1.2      2      13
Total:          1    2   1.2      2      13

Percentage of the requests served within a certain time (ms)
  50%      2
  66%      2
  75%      2
  80%      2
  90%      3
  95%      3
  98%      5
  99%     11
 100%     13 (longest request)
    ~/tmp/ruby ⌘