Malcom Gilbert mjgil

Backend Architectures

ARCHITECTURES

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

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

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

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

	/**
	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

	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'