About EventMachine 
What is EventMachine
EventMachine is an event-driven I/O and lightweight concurrency library for Ruby.
It provides event-driven I/O using the Reactor pattern,
much like JBoss Netty, Apache MINA,
Python's Twisted, Node.js, libevent and libev.
EventMachine is designed to simultaneously meet two key needs:
- Extremely high scalability, performance and stability for the most demanding production environments.
- An API that eliminates the complexities of high-performance threaded network programming,
allowing engineers to concentrate on their application logic.
This unique combination makes EventMachine a premier choice for designers of critical networked
applications, including Web servers and proxies, email and IM production systems, authentication/authorization
processors, and many more.
EventMachine has been around since the early 2000s and is a mature and battle-tested library.
What EventMachine is good for?
EventMachine supports Ruby 2.0.0 through 2.6, JRuby and works well on Windows as well
as many operating systems from the Unix family (Linux, Mac OS X, BSD flavors).
Install the gem
Install it with RubyGems
gem install eventmachine
or add this to your Gemfile if you use Bundler:
gem 'eventmachine'
Getting started
For an introduction to EventMachine, check out:
Server example: Echo server
Here's a fully-functional echo server written with EventMachine:
require 'eventmachine'
module EchoServer
def post_init
puts "-- someone connected to the echo server!"
end
def receive_data data
send_data ">>>you sent: #{data}"
close_connection if data =~ /quit/i
end
def unbind
puts "-- someone disconnected from the echo server!"
end
end
# Note that this will block current thread.
EventMachine.run {
EventMachine.start_server "127.0.0.1", 8081, EchoServer
}
EventMachine documentation
Currently we only have reference documentation and a wiki.
Community and where to get help
- Join the mailing list (Google Group)
- Join IRC channel #eventmachine on irc.freenode.net
License and copyright
EventMachine is copyrighted free software made available under the terms
of either the GPL or Ruby's License.
Copyright: (C) 2006-07 by Francis Cianfrocca. All Rights Reserved.
Alternatives
If you are unhappy with EventMachine and want to use Ruby, check out Celluloid.
