MD mengdiwang

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

Setting up a SSL Cert from Comodo

I use Namecheap.com as a registrar, and they resale SSL Certs from a number of other companies, including Comodo.

These are the steps I went through to set up an SSL cert.

Purchase the cert

I heard from GitHub Two-Factor Authentication](https://github.com/blog/1614-two-factor-authentication) nearly a couple of days ago when I was reading my RSS feed. I enabled it and couldn' push to any of my repositories anymore. Learn in this blog post how to fix it.

Two-Factor Authentication

"Is a process involving two stages to verify the identity of an entity trying to access services in a computer or in a network". Github solves this authentication with sending an SMS to a device which wants to push to their platform.

Enabling Two-Factor Authentication

Setting up iOS Universal Links

	#!/bin/bash

	cd `dirname $0`

	curl\
	--remote-name \
	--remote-header-name\
	http://www.topcoder.com/contest/arena/ContestAppletProd.jnlp

	JAVAWS="/Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Home/bin/javaws"

	driver = 'mysql+pymysql://'
	driver = 'postgresql+psycopg2://'

	app.config['SQLALCHEMY_DATABASE_URI'] = driver \
	+ os.environ['RDS_USERNAME'] + ':' + os.environ['RDS_PASSWORD'] \
	+'@' + os.environ['RDS_HOSTNAME'] + ':' + os.environ['RDS_PORT'] \
	+ '/' + os.environ['RDS_DB_NAME']