Danil Pismenny dapi

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

	require 'bundler/vlad'
	require 'vlad/rvm'

	set :default_stage, 'production'

	set :shared_paths, {
	'log' => 'log',
	'system' => 'public/system',
	'pids' => 'tmp/pids',
	'sockets' => 'tmp/sockets',

	#!/bin/sh
	set -e
	# Example init script, this can be used with nginx, too,
	# since nginx and unicorn accept the same signals

	# Feel free to change any of the following variables for your app:
	TIMEOUT=${TIMEOUT-60}
	APP_ROOT=/path/to/your/app/current
	PID=$APP_ROOT/tmp/pids/unicorn.pid
	ENVIRONMENT=production

	location ~* ^/remote-files/(http[s]://)(.?)/(.*) {
	# Do not allow people to mess with this location directly
	# Only internal redirects are allowed
	internal;

	# nginx has to be able to resolve the remote URLs
	resolver 8.8.8.8;

	# Location-specific logging
	#access_log /usr/local/etc/nginx/logs/internal_redirect.access.log main;

	<!DOCTYPE html>
	<html>
	<head>
	<script src='http://ajax.googleapis.com/ajax/libs/jquery/1.5.2/jquery.min.js'></script>
	<script>
	$(document).ready(function(){
	function debug(str){ $("#debug").append("<p>"+str+"</p>"); };
	if(typeof WebSocket === 'undefined') {
	alert("Your browser does not support websockets.")
	}

	module ApiPageHelper
	PAGINATE_OPTIONS = {
	:default_page_size => 10
	}
	PAGINATE_PARAMS = [ "page", "offset", "size" ]
	def paginate(coll, options = {})
	options = PAGINATE_OPTIONS.merge(options)
	if params[:page]
	page = params[:page].to_i
	size = (params[:size] \|\| options[:default_page_size]).to_i

	# let's dig the server
	dig example.com

	# from the DNS answer we are interested in the authority section
	#;; AUTHORITY SECTION:
	#example.com. 79275 IN NS a.iana-servers.net.
	#example.com. 79275 IN NS b.iana-servers.net.

	# now we find out all subdomains
	dig @a.iana-servers.net example.com axfr

	# Расширение контроллера
	#
	module Bitrix::Authorization
	def current_user
	@current_user \|\|= find_from_cookie
	end

	def login_user(user)
	logout_user if current_user
	@current_user = user

	bash -c '

	#
	# make sure sudo users have the full path...
	#
	# sudo visudo
	# Defaults env_keep += "PATH"
	# Defaults !secure_path

	#

	Latency Comparison Numbers (~2012)
	----------------------------------
	L1 cache reference 0.5 ns
	Branch mispredict 5 ns
	L2 cache reference 7 ns 14x L1 cache
	Mutex lock/unlock 25 ns
	Main memory reference 100 ns 20x L2 cache, 200x L1 cache
	Compress 1K bytes with Zippy 3,000 ns 3 us
	Send 1K bytes over 1 Gbps network 10,000 ns 10 us
	Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD