Terry Wang terrywang

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns                     on recent CPU
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 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 4X memory

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.

THIS GIST WAS MOVED TO TERMSTANDARD/COLORS REPOSITORY.

PLEASE ASK YOUR QUESTIONS OR ADD ANY SUGGESTIONS AS A REPOSITORY ISSUES OR PULL REQUESTS INSTEAD!

check_puppet_run_health

A Nagios check that connects to PuppetDB and determines the Puppet agent run health on a host.

Requires

PuppetDB
A puppetmaster configured to send reports to PuppetDB

	#!/bin/bash

	# Your github username
	github_user="dcai"
	# The remote name of your github repo, it usually origin
	github_remote_name="github"


	### STOP CONFIG SINCE HERE! ###
	github_diff_root="https://github.com/$github_user/moodle/compare/"

	require "fileutils"
	root_dir = "/Users/jason/Downloads/images"
	Dir.chdir(root_dir)
	puts Dir.pwd
	Dir.glob("*/.{jpg}").each do \|fname\|
	tfname = fname.split("/").last
	if fname.match("[small\|large\|normal]_")
	tfname = fname.split("_").last
	end
	p1,p2 = tfname[0,1],tfname[1,1]

	#!/bin/sh
	# https://gist.github.com/smoser/5823699
	set -e

	[ "$(id -u)" = "0" ] && sudo="" \|\| sudo="sudo"
	[ -e "/usr/bin/apt-get.distrib" ] \|\|
	$sudo dpkg-divert --local --rename --add /usr/bin/apt-get

	$sudo tee /usr/bin/apt-get >/dev/null <<"EOF"
	#!/bin/sh

	# -- mode: ruby --
	# vi: set ft=ruby :

	# override these variables in ~/.vagrant.d/Vagrantfile for your local changes

	$local_username \|\|= `whoami`.strip
	$local_projects_directory \|\|= "~/projects/vagrant/"
	$vm_memory \|\|= "4096"
	$vm_cpus \|\|= "4"
	$server_root_password = "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"

	# based on http://stackoverflow.com/questions/549186/change-background-of-terminal-app-from-the-commandline

	function darkback {
	osascript -e "tell application \"Terminal\" to set background color of window 1 to {0,0,0}"
	}

	function lightback {
	osascript -e "tell application \"Terminal\" to set background color of window 1 to {65535,65535,65535}"
	}