OnePlaylist prod use case on using websocket, ruby-eventmachine via a HA-Proxy loadbalancer

1. websocket on ruby
oneplaylist.fm beta use case

2. The Stack
• ruby on rails
• redis
• ruby-eventmachine
• HA-Proxy

3. Other on Stack
• Resque: background processing in rails
• mongodb
• coffeescript js heavy
• elasticsearch (tire ruby gem)

4. HA-Proxy
• tcp level load balancer
• handle http level too
• super fast, and so on.....
• high availaibility made easy

5. HA-Proxy stack
• HA-Proxy -> 3 ruby on rails front
• HA-Proxy -> 3 elasticsearch instance
(direct from coffee)
• HA-Proxy -> event-machine tcp level
websocket

6. HA-Proxy websocket
• http://oneplaylist.fm -> app
• http://oneplaylist.fm/websocket -> tcp event
machine !!
• same ip, same domain, sub path !!!!

7. Redis and websocket ?
• handle stateless auth -> pass a token each
request pass from front
• redis is a central point of communication:
super fast and performant
• PUB SUB ! -> push to websocket

8. Redis and websocket
• each token -> a user id
• after authenticate, the eventmachine tcp
session register to redis pub pipe with key
user id
• all message to user from rails -> pub redis
key -> eventmachine redis -> websocket /
browser in real time of course

9. Rails -> redis
• Rails app write data in redis key before
pushing
• when user reconnect -> eventmachine
make a get on key and push back to
browser
• some part of app are render only with
webscoket data -> better consistency

10. more infos
• http://oneplaylist.fm
• https://twitter.com/mathieuel
• http://www.mathieu-elie.net