Node js techtalksto

Chief Architect

[email protected]

James A. Duncan

Node

Friday, March 4, 2011

mailto:[email protected]

mailto:[email protected]

Chief Architect @ Joyent

Spend a lot of my time thinking about how things should join together and why they shouldnʼt.

Grew up in Hawkesbury, Ontario

Live in the mountains to the north of Montreal in Quebec, Canada.

Formerly lived in London & was a CIO of a subsidiary of Canon Europe.

Open Source guy for 15 years.

Gardener, skier, and technologist.

James A. Duncan

2


C10K




Between 70-100 microprocessors

in a car!


1 flight, 1 plane, 480 TBs


Intel shipped 3.3 billion CPUs in Q1 2010

1.5ZBs of storage sold in 2010


Scale Up

From 1990 to 2010, “RAM” in computers increased 1,000,000x in the

same power footprint


Computer Scientistsand

Computer Engineers



the node.js project

To provide a purely evented, non-blocking infrastructure to script highly

concurrent programs.

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TwistedPOEEventMachine


TwistedPOE = Pain.EventMachine


a snippet of code

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...rows = db.select("col,umns FROM aTable WHERE aRow=‘foo’");do_something( rows );...


Computers can do nothing.Very fast.


L1: 3 cycles


L2: 14 Cycles


RAM: 250 cycles


Disk: 41,000,000 cycles


Network: 240,000,000 cycles


Anything that waits for a response from the disk, or the network can be considered “blocking” IO


a better snippet of code

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...sql = "col,umns FROM aTable WHERE aRow=‘foo’";db.select(sql, do_something);...


Computer can keep doing things very fast.


Asynchronous IO.


Alternatives


Multiple ProcessesThreadsGreen Threads, Coroutines


Asynchronous IO.Not New.


Cultural Biasputs("Enter your name: ");var name = gets();puts("Name: " + name)


Infrastructural Bias


Callbacks


C will never go away.


Man Pages


Library support


Async File IO

• BSD:

• poll/select

• Linux:

• epoll

• FreeBSD

• kqueue

• Solaris

• /dev/poll

• libevent, libev

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C will never go away.


C will never go away.Nor will JavaScript.


JavaScript is a cultural fit

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the node.js project

• Evented server-side javascript

• All IO is non-blocking

• Good at handling lots of different IO at the same time

• Achieves this by making all IO non-blocking

• Primary author, and benevolent dictator for life is Ryan Dahl

• Owned by us (Joyent), but MIT/BSD licensed

• seems to be pretty popular, which is making us happy

• running our http://no.de service - lets you get started using node quickly

• running on HPʼs webOS as the underlying service mechanism (replaced Java)

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http://no.de

http://no.de

a pleasing example

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var http = require("http");var net = require("net");var c = 0;

http.createServer( function( req, res ) { c++; res.writeHead(200); res.end("Hello World");}).listen(8000);

net.createServer( function( socket ) { socket.write("connections: " + c); socket.end();}).listen(8001);


speed is obviously important

• Benchmark:

• nginx v0.7.65

• node v0.1.91

• tornado v0.2 (python 2.6.4)

• thin v1.2.7 (ruby 1.9.1-p376)

• Linux 2.53, using Intel Core 2 Duo & 4GB RAM

• Standard hello world, with a 100 byte response

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establish the competition

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Why is nginx so fast?


plot node.js results

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what if we change the response size?

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Implementation

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buffer = new Buffer(16*1024);for (i = 0; i < buffer.length; i++) { buffer[i] = 100;}

http.createServer(function(req, res){ res.writeHead(200); res.end(buffer);});


JavaScript is only a little bit slower than lovingly hand-crafted optimized C.


JavaScript is only a little bit slower than lovingly hand-crafted optimized C. Wow.


How is this true?



ECMAScript




Speedy

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Dogfood.



Libraries


var express = require('express');var app = express.createServer();

app.get("/", function(req, res, next) { res.send("Hello from the URL " + req.url);});

app.get(“/:name”, function(req, res, next) { res.send(“Hello “ + req.params.name);});app.listen(3000);

Web Framework - Express

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Connect Middleware


Databases


Multi-process


npm


Demo App


Conclusions& Thanks for Listening!


Documents

Node js techtalksto