1.
An Introduction to
WebSockets
Steve Agalloco
May 20th 2010
twitter.com/anno
beforeitwasround.com
steveagalloco.com

2.
About Me
• New to Charlotte (Hello!)
• Developer at TradeKing
• recovering Java programmer, currently
working primarily with Ruby and Rails
• interested in NoSQL, Node, HTML5

3.
Realtime Web
• Round Trips - meta refresh, onchange
events
• Ajax
• Comet - long polling
• Flash XMLSocket

4.
The ugly side of Ajax

5.
The ugly side of Comet

6.
WebSockets
• Part of HTML5
• Bi-directional communication between
browser and server
• Works with Proxy/Firewall
• Less network overhead
• Faster than Ajax/Comet

7.
More Details
• It’s own protocol (ws://)
• different headers
• Language support - libraries available for
Ruby, Node.js, Erlang, PHP, Java, Python, etc.

8.
Possible Uses
• Realtime Data - Chat, Stocks, Sports
• Presence
• Collaboration
• Notifications

9.
Browser Support
• Chrome and WebKit support now
• Safari 4.x (anticipated)
• Firefox 4.0 (expected in November 2010)
• Internet Explorer (no indications it’ll be
supported in IE 9)
• Fallback to our old friend... Flash
http://github.com/gimite/web-socket-js

10.
Client-Side Code

11.
Example

12.
In the Wild
• http://hummingbirdstats.com
• http://pusherapp.com

13.
Thank You!
• http://github.com/spagalloco - Fork me!
• http://github.com/spagalloco/websockets-
example