1. Introduction to
Node.JS
Pragnesh Vaghela | @technologythree | technologythree.com

2. Problem
what’s a really common thing to do in a web application?
Database access, of course. Too bad database I/O is one of the
slowest things a web app has to deal with
data = readFromDatabase();
printData(data);
doSomethingUnrelated();
asynchronous JavaScript:
readFromDatabase(function(data) {
printData(data);
})
doSomethingUnrelated();
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3. NODE.JS
1. platform built on Chrome's JavaScript runtime for
easily building fast, scalable network applications
2. perfect for data-intensive real-time applications that
run across distributed devices
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4. NODE.JS
1. server-side JavaScript framework - the same type of
code that powers awesome Ajax applications like
Gmail will now power its servers, too
2. driven by asynchronous design - that it doesn’t have
to wait for slow file I/O or database operations to
continue processing, which makes it really damn
fast. It also means that it can handle millions of
concurrent connections at once
3. real-time applications - you do not have to bother
with low-level sockets and protocols
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5. Bad Use Cases
1. apps that are very heavy on CPU usage, and very
light on actual I/O - video encoding software,
artificial intelligence or similar CPU hungry software
2. simple CRUD / HTML apps
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6. Good Use Cases
• JSON APIs
building light-weight REST / JSON api's is something where
node.js really shines. Its non-blocking I/O model combined
with JavaScript make it a great choice for wrapping other data
sources such as databases or web services and exposing them
via a JSON interface
• Single page Apps
if you are planning to write an AJAX heavy single page app
(think gmail), node.js is a great fit as well. The ability to
process many requests / seconds with low response times, as
well as sharing things like validation code between the client
and server make it a great choice for modern web
applications that do lots of processing on the client
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7. Good Use Cases
• Streaming data
one great example is parsing file uploads in real time, as well
as building proxies between different data layers
• Soft Realtime Applications
easy to develop soft real time systems like twitter, chat
software, sport bets or interfaces to instant messaging
networks
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8. Example Web Server
var http = require('http');
http.createServer(function (request, response) {
response.writeHead(200, {'Content-Type': 'text/plain'});
response.end('Hello Worldn');
}).listen(8124);
console.log('Server running at http://127.0.0.1:8124/');
To run the server, put the code into a file called example.js and
execute it with the node program:
> node example.js
Server running at http://127.0.0.1:8124/
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9. Real world Node.JS
Applications
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10. NODE.JS in the industry
1. CBS, Linkedin use Node.js for mobile
2. Walmart’s Node-powered mobile app front-end code
gets executed on the back end
3. Yahoo has released some things for Node, and supports
cocktails - a Node.js platform. It also uses Node.js in the
livestand infrastructure
4. Mozilla has implemented Node.js to support browser
APIs which has half a billion installs
5. Pinterest uses Node as a webserver in some instances
6. Ebay hosts their HTTP API service with Node
7. HP uses Node for their WebOS initiatives
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11. Thank You
Pragnesh Vaghela | @technologythree | technologythree.com