"A dizzying lifetime... Reeling by on Celluloid" -- Rush / Between The Wheels
Reel is a fast, non-blocking "evented" web server built on http_parser.rb, websocket_parser, Celluloid::IO, and nio4r. Thanks to Celluloid, Reel also works great for multithreaded applications and provides traditional multithreaded blocking I/O support too.
Connections to Reel can be either non-blocking and handled entirely within the Reel::Server thread, or the same connections can be dispatched to worker threads where they will perform ordinary blocking IO. Reel provides no built-in thread pool, however you can build one yourself using Celluloid.pool, or because Celluloid already pools threads to begin with, you can simply use an actor per connection.
This gives you the best of both worlds: non-blocking I/O for when you're primarily I/O bound, and threads for where you're compute bound.
Here's a "hello world" web server benchmark, run on a 2GHz i7 (OS X 10.7.3). All servers used in a single-threaded mode.
Reel performance on various Ruby VMs:
# httperf --num-conns=50 --num-calls=1000
Ruby Version Throughput Latency
------------ ---------- -------
JRuby 1.7.0 3978 req/s (0.3 ms/req)
rbx HEAD 2288 reqs/s (0.4 ms/req)
Ruby 1.9.3 2071 req/s (0.5 ms/req)
Comparison with other web servers:
Web Server Throughput Latency
---------- ---------- -------
Goliath (0.9.4) 2058 reqs/s (0.5 ms/req)
Thin (1.2.11) 7502 reqs/s (0.1 ms/req)
Node.js (0.6.5) 11735 reqs/s (0.1 ms/req)
All Ruby benchmarks done on Ruby 1.9.3. Latencies given are average-per-request and are not amortized across all concurrent requests.
Reel also provides a "bare metal" API which was used in the benchmarks above. Here are some examples:
Reel lets you pass a block to initialize which receives connections:
require 'reel'
Reel::Server.supervise("0.0.0.0", 3000) do |connection|
while request = connection.request
case request
when Reel::Request
puts "Client requested: #{request.method} #{request.url}"
request.respond :ok, "Hello, world!"
when Reel::WebSocket
puts "Client made a WebSocket request to: #{request.url}"
request << "Hello everyone out there in WebSocket land"
request.close
break
end
end
end
sleep
When we read a request from the incoming connection, we'll either get back a Reel::Request object, indicating a normal HTTP connection, or a Reel::WebSocket object for WebSockets connections.
You can also subclass Reel, which allows additional customizations:
require 'reel'
class MyServer < Reel::Server
def initialize(host = "127.0.0.1", port = 3000)
super(host, port, &method(:on_connection))
end
def on_connection(connection)
while request = connection.request
case request
when Reel::Request
handle_request(request)
when Reel::WebSocket
handle_websocket(request)
end
end
end
def handle_request(request)
request.respond :ok, "Hello, world!"
end
def handle_websocket(sock)
sock << "Hello everyone out there in WebSocket land!"
sock.close
end
end
MyServer.run
Reel can be used as a standard Rack server via the "reel" command line application. Please be aware that Rack support is experimental and that there are potential complications between using large numbers of rack middlewares and the limited 4kB stack depth of Ruby Fibers, which are used extensively by Celluloid. In addition, the Rack specification mandates that request bodies are rewindable, which prevents streaming request bodies as the spec dictates they must be written to disk.
To really leverage Reel's capabilities, you must use Reel via its own API, or another Ruby library with direct Reel support.
The most notable library with native Reel support is webmachine-ruby, an advanced HTTP framework for Ruby with a complete state machine for proper processing of HTTP/1.1 requests. Together with Reel, Webmachine provides full streaming support for both requests and responses.
To use Reel with Webmachine, add the following to your Gemfile:
gem 'webmachine', git: 'git://github.com/seancribbs/webmachine-ruby.git'
Then use config.adapter = :Reel
when configuring a Webmachine app, e.g:
MyApp = Webmachine::Application.new do |app|
app.routes do
add ['*'], MyHome
end
app.configure do |config|
config.ip = MYAPP_IP
config.port = MYAPP_PORT
config.adapter = :Reel
# Optional: (WM master only) handler for incoming websockets
config.adapter_options[:websocket_handler] = proc do |websocket|
# socket is a Reel::WebSocket
socket << "hello, world"
end
end
end
MyApp.run
See the Webmachine documentation for further information
- Fork this repository on github
- Make your changes and send me a pull request
- If I like them I'll merge them
- If I've accepted a patch, feel free to ask for commit access
Copyright (c) 2012 Tony Arcieri. Distributed under the MIT License. See LICENSE.txt for further details.