Initially delivered at LA RubyConf 2013, this presentation describes how cutting-edge technology helped to triple performance and drastically cut costs in a mobile social game. Juan Pablo Genovese, a Ruby Architect from Altoros Systems Argentina, explains how, despite the extremely tight budget, the customer managed to: - go from ~450 req/s to ~1300 req/s - reduce the number of EC2 application servers from four to one - provide fast and reliable video uploading and processing - achieve very easy scaling with automation while maintaining all the functions of the original RoR app.

1. Helping your customers to cut costs in their web APIs.

2.  16 years in Software Development
 From S/390 to Android
 In love with Ruby since 2006
 Working in
 @eljuanchosf
 Love to dance Tango and play Blues guitar

3.  Set of programming components and
standards.
 Open up your app to the world.
 Integration!

4.  Mobile social game (iOS & Android)
 Video upload & encoding
 JSON API
 AWS -> EC2/S3

5. Autoscale with
Scalr.com

6.  Find a way to cut costs and improve
performance.
 Provide a very easy way to scale the new
solution.
 Maintain all the RoR application
functionality, focusing on APIs for the mobile
clients.
 Tight, TIGHT budget.

7.  Inspiration: Draw Something –
http://goo.gl/hi7a6
 Goliath
 Beanstalk
 Couchbase
 HAProxy as load balancer.
 Varnish

8.  Asynchronous (non-blocking) web server framework.
 Based on EventMachine
 Lightweight
 Rack API & middleware support
 Very simple yet powerful configuration
 Fully async processing
 Websockets out of the box
 No callbacks!!
 Low memory footprint (only 65 KB!)
 0.3 ms from top -> bottom!
 http://postrank-labs.github.com/goliath/

9.  Very simple, very fast work queue.
 Saves memory (lots of it).
 Multiple queues.
 Generic interface.
 Several Ruby clients to choose from.
 Send your Ruby object as a JSON.
 Parallel and asynchronous.
 Scales VERY easily.
 http://kr.github.com/beanstalkd/

10.  Ruby implementation of the Reactor Pattern
 Highly scalable
 Performance optimized
 Mature & stable
 Eliminates the complexities of threaded network
programming.
 Active community
 Examples: Thin & Goliath.

11.  October 1995 by Douglas Schmidt
 AKA Dispatcher or Notifier
 Handle requests delivered to an application by one
or more clients.
 Single threaded by definition
 Separates application logic from the reactor
implementation
 Task switching = no multithreading!

13. EM.run {
EM::HttpRequest.new(‘http://www.example.com’).get.callback {
|http|
puts http.response
}
}

14. EM::HttpRequest.new(first_url).get.callback {|http|
second_url = extract_next_url(http.response)
EM::HttpRequest.new(second_url).get.callback {|http2|
puts http2.response
}
}

15. require 'em-synchrony/em-http'
http = EM::HttpRequest.new(first_url).get
second_url = extract_next_url(http.response)
http2 = EM::HttpRequest.new(second_url).get
No callbacks and still asynchronous!!!

16.  https://github.com/igrigorik/em-synchrony
 https://github.com/eventmachine/eventmachine/wiki/protoc
ol-implementations

17.  Latest version has no built-in routing system.
 Ilya Grigorik (Goliath’s creator) suggests to
start multiple Goliath servers, each one with
one endpoint and use HAProxy or any reverse
proxy to route the requests.
 That’s kind of cumbersome, don’t you think?

18.  Routing was done thru convention over
configuration with a little of Ruby’s reflection
abilities mixed with some inheritance:
 http://server/api/game/CreateGame was redirected to the
api/game/create_game.rb controller:
class CreateGame < APIController
.
.
.
.
end

19.  Goliath: add processes or servers and
configure them in HAProxy.
 Couchbase: add servers to the cluster.
 Done!
(we used Scalar to automate this, too)

20.  From ~450 req/s to ~1300 req/s.
 From 4 to 1 EC2 application servers.
 Triple performance while reducing costs.
 Video upload and processing fast and
reliable: ~250 jobs/s

21.  Contact Juan Pablo @eljuanchosf
 Contact Altoros Systems http://altoros.com/contact_us.html