Justin Holmes justinholmes

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

	---
	- hosts: localhost
	connection: local
	tasks:
	- name: add apt repo
	apt_repository: repo='ppa:ubuntu-lxc/lxd-stable'

	- name: install lxc and lxd
	apt: name=lxd state=latest update_cache=yes cache_valid_time=600

	# Documentation for HAProxy
	# http://code.google.com/p/haproxy-docs/w/list
	# http://haproxy.1wt.eu/download/1.2/doc/architecture.txt

	# NOTES:
	# open files limits need to be > 256000, use ulimit -n to set (on most POSIX systems)

	global
	log 127.0.0.1 local0
	log 127.0.0.1 local1 notice

	package controllers

	import org.squeryl.PrimitiveTypeMode._
	import org.squeryl.{Session}

	import play.api._
	import play.api.mvc._

	import models._