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

CMCDragonkai

Understanding the Memory Layout of Linux Executables

Required tools for playing around with memory:

• hexdump
• objdump
• readelf
• xxd
• gcore

troyharvey

# Use envFrom to load Secrets and ConfigMaps into environment variables

apiVersion: apps/v1beta2
kind: Deployment
metadata:
  name: mans-not-hot
  labels:
    app: mans-not-hot
spec:
  replicas: 1

niieani

#!/usr/bin/env bash

declare -i last_called=0
declare -i throttle_by=2

@throttle() {
  local -i now=$(date +%s)
  if (($now - $last_called >= $throttle_by))
  then
    "$@"

sawanoboly

#!/usr/bin/env ruby
# -*- coding:utf-8 -*-
require 'socket'
require 'openssl'
require 'timeout'
require 'pp'
include OpenSSL

timeout=15

everbeen

package main

import (
	"bytes"
	"encoding/gob"
	"fmt"
	"github.com/ugorji/go/codec"
	"io/ioutil"
	"labix.org/v2/mgo"
	"labix.org/v2/mgo/bson"

niflostancu

Installing Ubuntu 16.04 with btrfs using debootstrap

Partition layout

First, create a GPT partition table.

1. boot partition, label: EFI, flags: boot + ESP; size: 1GB, format to FAT32;
2. root partition (label: root), must same size on all devices!
3. swap partition.

karolyi

#!/usr/bin/env bash
mariabackup --stream=xbstream --backup --user root|pigz >mariadb-backup.gz

nevans

# Pass in an enumeration of data and
# (optionally) a block to extract the grouping aspect of the data.
#
# Optional: sort_by lambda (operates on group key and count)
#
def puts_hist(data, sort_by:nil, &blk)
  data   = data.map(&blk) if blk
  counts = data.each_with_object(Hash.new(0)) {|k,h| h[k]+=1}
  max    = counts.values.max
  width  = Pry::Terminal.size!.last

anarchivist

#!/bin/bash

# Slack notification script for Munin
# Mark Matienzo (@anarchivist)
#
# To use:
# 1) Create a new incoming webhook for Slack
# 2) Edit the configuration variables that start with "SLACK_" below
# 3) Add the following to your munin configuration:
#