seboudry

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

Belphemur

#!/usr/bin/env bash
 
# names of latest versions of each package
export NGINX_VERSION=1.15.5
export VERSION_NGINX=nginx-$NGINX_VERSION
export VERSION_LIBRESSL=libressl-2.8.1
export VERSION_PCRE=pcre-8.42
#export NPS_VERSION=1.9.32.10
#export VERSION_PAGESPEED=v${NPS_VERSION}-beta
 

grugq

Operational PGP

This is a guide on how to email securely.

There are many guides on how to install and use PGP to encrypt email. This is not one of them. This is a guide on secure communication using email with PGP encryption. If you are not familiar with PGP, please read another guide first. If you are comfortable using PGP to encrypt and decrypt emails, this guide will raise your security to the next level.

kachayev

Channels Are Not Enough

... or Why Pipelining Is Not That Easy

Golang Concurrency Patterns for brave and smart.

By @kachayev

Intro

pinge

How to install Ubuntu 14.04.1 LTS 64-bit on a MacBook Pro Retina 15" Mid 2014 (11,3)

download

• Ubuntu 14.04 Desktop 64-bit ISO (default, non-Mac version)
  http://www.ubuntu.com/download/desktop
• UNetbootin
  http://unetbootin.sourceforge.net/
• Broadcom 802.11 Linux STA wireless driver source dependencies
  http://packages.ubuntu.com/trusty/all/dkms/download

lavalamp

There are three easy to make mistakes in go. I present them here in the way they are often found in the wild, not in the way that is easiest to understand.

All three of these mistakes have been made in Kubernetes code, getting past code review at least once each that I know of.

1. Loop variables are scoped outside the loop.

What do these lines do? Make predictions and then scroll down.

func print(pi *int) { fmt.Println(*pi) }

magnetikonline

BIND - delegate a sub domain for a zone

The scenario:

• DNS zone myzone.com defined in BIND.
• Authoritative name server at 123.16.123.1.
• Subzone sub.myzone.com with an authoritative name server at 123.16.123.10.
• Wishing to forward sub-zone to authoritative name server.

Config

AGWA

/*
 * Demonstrates that an RSA signature does not uniquely identify a public key.
 * Given a signature, s, and a message m, it's possible to construct a new RSA key
 * pair such that s is a valid signature for m under the new key pair.
 *
 * Requires Go version >= 1.5.  Go <= 1.4 doesn't work due to a bug in the bignum
 * package: https://github.com/golang/go/issues/9826
 *
 * Written in 2015 by Andrew Ayer <[email protected]>
 *

technion

#!/usr/bin/env ruby
# We're going to need a private key.
require 'openssl'
# Initialize the client
require 'acme/client'

# We need an ACME server to talk to, see github.com/letsencrypt/boulder
ENDPOINT = 'https://acme-v01.api.letsencrypt.org/'
#ENDPOINT = 'https://acme-staging.api.letsencrypt.org'
ACCOUNT_FILE = 'account_key.pem'

julz

package main

import (
	"fmt"
	"os"
	"os/exec"
	"syscall"
)

func main() {