Riza rizafr

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

Questions

Front-end Job Interview Questions https://github.com/h5bp/Front-end-Developer-Interview-Questions

JS quiz https://github.com/nathansmith/javascript-quiz

Homework

Moved to git repository: https://github.com/denji/nginx-tuning

NGINX Tuning For Best Performance

For this configuration you can use web server you like, i decided, because i work mostly with it to use nginx.

Generally, properly configured nginx can handle up to 400K to 500K requests per second (clustered), most what i saw is 50K to 80K (non-clustered) requests per second and 30% CPU load, course, this was 2 x Intel Xeon with HyperThreading enabled, but it can work without problem on slower machines.

You must understand that this config is used in testing environment and not in production so you will need to find a way to implement most of those features best possible for your servers.

Configuring Gammu in OSX with MySQL

Requirements:

Install Gammu
Install MySQL v5.5 (not working with 5.6 >)
Install wget

Step by step:

Check the sql files in here

Configuring Gammu for Mac OSX 10.11

Requirements

Disconnect modem first
Download and Install Driver USB Prolific for PL2303 Mac OS X
Reboot Mac
Install Homebrew

Step by step:

Type below command :

[ Launch: Arc Pie ] 04ca0aae958ff6e0e02d25e6ef466d74 by rizafr[ Launch: Arc Pie ] 48f51dcc6f9ccf536ff3f71add9a6877 by rizafr

	<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');

	/**
	* CodeIgniter Google Maps API V3 Class
	*
	* Displays a Google Map
	*
	* @package CodeIgniter
	* @subpackage Libraries
	* @category Libraries

	// Demo: http://jsfiddle.net/xuyp8qb5/
	// Note: You need Google Map API Key to run demo; bit.ly/2pBgToW

	var latlng;
	latlng = new google.maps.LatLng(40.730885, -73.997383); // New York, US
	//latlng = new google.maps.LatLng(37.990849233935194, 23.738339349999933); // Athens, GR
	//latlng = new google.maps.LatLng(48.8567, 2.3508); // Paris, FR
	//latlng = new google.maps.LatLng(47.98247572667902, -102.49018710000001); // New Town, US
	//latlng = new google.maps.LatLng(35.44448406385493, 50.99001635390618); // Parand, Tehran, IR
	//latlng = new google.maps.LatLng(34.66431108560504, 50.89113940078118); // Saveh, Markazi, IR

	function slugify(text)
	{
	return text.toString().toLowerCase()
	.replace(/\s+/g, '-') // Replace spaces with -
	.replace(/[^\w\-]+/g, '') // Remove all non-word chars
	.replace(/\-\-+/g, '-') // Replace multiple - with single -
	.replace(/^-+/, '') // Trim - from start of text
	.replace(/-+$/, ''); // Trim - from end of text
	}

	# to generate your dhparam.pem file, run in the terminal
	openssl dhparam -out /etc/nginx/ssl/dhparam.pem 2048