Node.js

@ samshull Who is this guy? Follow along: http://ta.gd/samsnodepresentation

Topics
What is it? How does it differ?
Why to use it?

What is node.js?
Evented I/O for JavaScript
Server Side JavaScript Runs on Google's V8 JavaScript Engine

node.js is not threaded!
Node.js uses a event driven non-blocking concurrency model Like a web browser!

Synchronous Model

Threaded Model

Evented Model

How does it differ?
"Node is similar in design to and influenced by systems like Ruby's Event Machine or Python's Twisted . Node takes the event model a bit further—it presents the event loop as a language construct instead of as a library."
-- nodejs.org

Traditional I/O
var fs = require( 'fs' ),
fd = fs.open( '/path/to/file' , 'r' ),
line = fs.read(fd, 100 );
while (line) {
console.log(line);
line = fs.read(fd, 100 );
}

File Read from Stream
require( 'fs' ).createReadStream( '/path/to/file' , {

'flags' : 'r'
, 'bufferSize' : 4 * 1024
}).on( 'data' , function (data) {
console.log(data); });

Basic HTTP Server
require( 'http' ).createServer( function (req, res) {

res.writeHead( 200 , { 'Content-Type' : 'text/plain' });
res.end( 'Hello World ' );

}).listen( 8124 , '127.0.0.1' );

Events
A TCP server emits a `connection` event each time a connection is made.
A HTTP request emits a `data` event each time a packet is received.
A readable file stream emits a `data` event each time the requested buffer is read into memory.

Typical Web Page Client Server Database

Web Application Client Server Database

Future Web Application Client Server Database

Why to use it?
"Node's goal is to provide an easy way to build scalable network programs."
--nodejs.org
"Node perfectly fills the proxy and authentication layer between the storage backend and client" --nodejs.org No waiting for a blocking database call or file system call allows developers to create faster systems

Benefits Efficient resource multiplexing by preventing MUTEX locks Multi-process resource sharing with libraries, like multi-node, take advantage of multi-core CPUs Up to 20,000 streams can be handled by a single thread without thread safety issues

Awesomeness
It's fast
It can handle tons of concurrent requests
It's written in JavaScript (which means you can use the same code server side and client side...way cool)
* http://www.synchrosinteractive.com/blog/3-websites/22-nodejs-has-a-bright-future Platform Number of Requests per seconds PHP (via Apache) 3187.27 Static (via Apache) 2966.51 Node.js 5569.30

Links
http://github.com/ry/node - Source code

http://nodejs.org/ - Documentation
http://ta.gd/realtimemousetracking - Real Time Example

http://github.com/kriszyp/multi-node - Multi-node

Node.js

by Sam Shull

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Node.js Presentation Transcript