mikemrm

#!/bin/sh

set -e -o pipefail

install_nat(){
  local int_iface="$1"; shift
  local ext_iface="$1"

  if [[ "$(sysctl net.ipv4.ip_forward)" =~ .*0$ ]]; then
    echo "Enabling ipv4 forwarding" >&2

egernst

Pre-requisites

Install IPMItools using your package manager on laptop and target machine. Load the drivers on the target.

modprobe ipmi_devintf
modprobe ipmi_si

If you see the following, drivers are not loaded.

skreuzer

global:
  evaluation_interval: 15s
rule_files:
  - smokeping.rules
scrape_configs:
  - job_name: 'blackbox_icmp'
    metrics_path: /probe
    params:
      module: [icmp]
    scrape_interval: 1s

sdstrowes

Source: https://web.archive.org/web/20141216073338/https://gkbrk.com/blog/read?name=reverse_engineering_the_speedtest_net_protocol Author: Gökberk Yaltıraklı

Reverse Engineering the Speedtest.net Protocol

After finishing my command line speed tester written in Rust, I didn't have a proper blog to document this process. A few days ago I wrapped up a simple blogging script in Python so hopefully it works good enough to explain how everything works.

By now I have already figured out the whole protocol for performing a speed test but I will write all the steps that I took so you can learn how to reverse engineer a simple protocol.

The code that I wrote can be found at https://github.com/gkbrk/speedtest-rust.

lichti

git clone https://github.com/certbot/certbot /opt/letsencrypt

ln -s /opt/letsencrypt/certbot-auto /usr/bin/certbot

certbot certonly --expand --agree-tos --text --non-interactive \
 --standalone \

JamieMason

Unfollow everyone on twitter.com

1. Go to https://twitter.com/YOUR_USER_NAME/following
2. Open the Developer Console. (COMMAND+ALT+I on Mac)
3. Paste this into the Developer Console and run it

// Unfollow everyone on twitter.com, by Jamie Mason (https://twitter.com/fold_left)
// https://gist.github.com/JamieMason/7580315
//

dmytro

#!/bin/bash
# ssh-multi
# D.Kovalov
# Based on http://linuxpixies.blogspot.jp/2011/06/tmux-copy-mode-and-how-to-control.html

# a script to ssh multiple servers over multiple tmux panes


starttmux() {
    if [ -z "$HOSTS" ]; then

hellerbarde

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

jboner

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

chitchcock

Stevey's Google Platforms Rant

I was at Amazon for about six and a half years, and now I've been at Google for that long. One thing that struck me immediately about the two companies -- an impression that has been reinforced almost daily -- is that Amazon does everything wrong, and Google does everything right. Sure, it's a sweeping generalization, but a surprisingly accurate one. It's pretty crazy. There are probably a hundred or even two hundred different ways you can compare the two companies, and Google is superior in all but three of them, if I recall correctly. I actually did a spreadsheet at one point but Legal wouldn't let me show it to anyone, even though recruiting loved it.

I mean, just to give you a very brief taste: Amazon's recruiting process is fundamentally flawed by having teams hire for themselves, so their hiring bar is incredibly inconsistent across teams, despite various efforts they've made to level it out. And their operations are a mess; they don't real