1. Ruby on Rails &
WebSocket
Le Hoai Phuong
Nguyen Huy Hung Hoang Van Quan
Cao Duy Khanh Vu Van Chuyen
Timeless

2. ● WebSocket Overview
● Benefit
● How does WS work?
● Pros & Cons
● WebSocket on Rails
● Summary
Content

3. WebSocket Overview
● Full-duplex channels over a single TCP
connection
● Was standardized in 2011
● Use an HTTP Upgrade request for
handshaking

4. Upgrade Request
GET /chat HTTP/1.1
Host: server.example.com
Upgrade: websocket
Connection: Upgrade
Sec-WebSocket-Key: x3JJHMbDL1EzLkh9GBhXDw==
Sec-WebSocket-Protocol: chat, superchat
Sec-WebSocket-Version: 13
Origin: http://example.com
HTTP/1.1 101 Switching Protocols
Upgrade: websocket
Connection: Upgrade
Sec-WebSocket-Accept: HSmrc0sMlYUkAGmm5OPpG2HaGWk=
Sec-WebSocket-Protocol: chat
Client Request
Server Response

5. WebSocket Benefit
● Overhead of HTTP
○ 1 HTTP request/response Header: 871 bytes
○ 1 WS frame: 2 bytes
● Low Latency

7. How does it work?

8. Pros & Cons
● Pros
○ Realtime
○ Lightweight
○ Low latency
○ Full duplex
● Cons
○ Still in working progress
○ Not suitable for streaming large data (HD video)
○ Hard to control multi-channels

9. WebSocket on Rails
● Web server
○ Event Based
○ or Client WS simulation using JavaScript
● Many gems: websocket-rails, em-websocket,
evma_httpserver

10. Reactor pattern
Request
EventMachine
(demultiplexer
- dispatcher)
Thin
(Web Server)
Rack Rails
adapter
Rack Thin
handler
Rails

11. A demo coding with gem websocket-rails

12. Summary
● Realtime
● New
● Lightweight
● Full duplex