Malcom Gilbert mjgil

Data visualization in one of three most important steps in data mining (https://github.com/entaroadun/hnpickup#readme). Often times, it's impossible to understand data without proper visualization. I went looking for great tools to do that.

Two website list recent JS visualization frameworks:

Most of them are available on Github. My three favorite:

https://github.com/DmitryBaranovskiy/g.raphael

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

Each of these commands will run an ad hoc http static server in your current (or specified) directory, available at http://localhost:8000. Use this power wisely.

Discussion on reddit.

Python 2.x

$ python -m SimpleHTTPServer 8000

Backend Architectures

ARCHITECTURES

Twitter

ror, scala, jetty, erlang, thrift, mongrel, comet server, my-sql, memchached, varnish, kestrel(mq), starling, gizzard, cassandra, hadoop, vertica, munin, nagios, awstats

Setup a Local Only SMTP Email Server (Linux, Unix, Mac)

1 - Point localhost.com to your machine

Most of programs will not accept an email using just @localhost as domain. So, edit /etc/hosts file to make the domain localhost.com point to your machine, including this content to the file:

127.0.0.1 localhost.com

2 - Install Postfix

Clustering: The basics

The trick? pass the file descriptor from a parent process and have the server.listen reuse that descriptor. So multiprocess in their own memory space (but with ENV shared usually)

It does not balance, it leaves it to the kernel.

In the last nodejs > 0.8 there is a cluster module (functional although marked experimental)

http://nodejs.org/api/cluster.html
Simple cluster example:

	require.config({
	baseUrl: '/backbone-tests/',
	paths: {
	'jquery' : '/app/libs/jquery',
	'underscore' : '/app/libs/underscore',
	'backbone' : '/app/libs/backbone',
	'mocha' : 'libs/mocha',
	'chai' : 'libs/chai',
	'chai-jquery' : 'libs/chai-jquery',
	'models' : '/app/models'

	/**
	Returns a bounding rect for _el_ with absolute coordinates corrected for
	scroll positions.

	The native `getBoundingClientRect()` returns coordinates for an element's
	visual position relative to the top left of the viewport, so if the element
	is part of a scrollable region that has been scrolled, its coordinates will
	be different than if the region hadn't been scrolled.

	This method corrects for scroll offsets all the way up the node tree, so the

	"""
	MIT License

	Copyright (c) 2017 Cyrille Rossant

	Permission is hereby granted, free of charge, to any person obtaining a copy
	of this software and associated documentation files (the "Software"), to deal
	in the Software without restriction, including without limitation the rights
	to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	copies of the Software, and to permit persons to whom the Software is

	// pre-render d3 charts at server side
	var d3 = require('d3')
	, jsdom = require('jsdom')
	, fs = require('fs')
	, htmlStub = '<html><head></head><body><div id="dataviz-container"></div><script src="js/d3.v3.min.js"></script></body></html>'

	jsdom.env({
	features : { QuerySelector : true }
	, html : htmlStub
	, done : function(errors, window) {