Ankush Sharma darxtrix

Getting Started with NPM (as a developer)

As easy as 1, 2, 3!

Updated:

Aug, 08, 2022 update config docs for npm 8+
Jul 27, 2021 add private scopes
Jul 22, 2021 add dist tags
Jun 20, 2021 update for --access=public
Sep 07, 2020 update docs for npm version

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

OS X Screencast to animated GIF

This gist shows how to create a GIF screencast using only free OS X tools: QuickTime, ffmpeg, and gifsicle.

Instructions

To capture the video (filesize: 19MB), using the free "QuickTime Player" application:

OpenVPN on Ubuntu 12.10 at DigitalOcean

Install OpenVPN

sudo apt-get install openvpn

Generate Server Certificates

sudo cp -r /usr/share/doc/openvpn/examples/easy-rsa/2.0 /etc/openvpn/easy-rsa2

cd /etc/openvpn/easy-rsa2

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.

Virtual Hosts on nginx (CSC309)

When hosting our web applications, we often have one public IP address (i.e., an IP address visible to the outside world) using which we want to host multiple web apps. For example, one may wants to host three different web apps respectively for example1.com, example2.com, and example1.com/images on the same machine using a single IP address.

How can we do that? Well, the good news is Internet browsers

	import urllib2
	import threading
	from Queue import Queue
	import sys, os, re

	class ThreadedDownload(object):

	REGEX = {
	'hostname_strip':re.compile('.\..?/', re.I)
	}

	# this will install everything as root, so take that into account before you run it

	# need cmake, python development headers, ZLib and OpenSSL
	sudo apt-get install cmake python2.7-dev zlib1g-dev libssl-dev

	mkdir libgit && cd libgit

	git clone git://github.com/libgit2/libgit2.git

	cd libgit2

	[
	{
	"keys": ["ctrl+w"],
	"command": "run_multiple",
	"args": {
	"commands": [
	{"command": "find_under_expand", "args": null, "context": "window"},
	{"command": "show_panel", "args": {"panel": "find"}, "context": "window"}
	]
	}

	# coding=utf-8
	"""
	LICENSE http://www.apache.org/licenses/LICENSE-2.0
	"""
	import datetime
	import sys
	import time
	import threading
	import traceback
	import SocketServer