Lee Trout leetrout

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

AWS Grok patterns for load balancer logs

Connection logs

https://docs.aws.amazon.com/elasticloadbalancing/latest/application/load-balancer-connection-logs.html#connection-log-entry-format

Sample logs:

2023-10-04T17:05:15.514108Z 203.0.113.1 36280 443 TLSv1.2 ECDHE-RSA-AES128-GCM-SHA256 4.036 "CN=amazondomains.com,O=endEntity,L=Seattle,ST=Washington,C=US" NotBefore=2023-09-21T22:43:21Z;NotAfter=2026-06-17T22:43:21Z FEF257372D5C14D4 Success

How to easily setup PXE boot for cluster provisioning

This guide will show you how to setup a PXE boot server to provision a cluster of machines. For the sake of this guide, we will be using system agnostic docker containers to simulate the DHCP and the PXE boot server.

Featured technologies:

	#!/bin/bash

	# Run PXE boot server on interface
	# Seems to work with UEFI and Secureboot
	# Spip, 2023
	#
	# Most stuff from https://www.youtube.com/watch?v=E_OlsA1hF4k
	#

	# Check args

	#!/bin/bash

	# Credit to https://gist.github.com/alisdair/ffc7c884ee36ac132131f37e3803a1fe for the excellent original
	# script that this one is based on. This script modifies the original to create the all-the-way-down effect.

	# Generate a `:*-all-the-way-down:` Slack emoji, given a reasonable image
	# input. I recommend grabbing an emoji from https://emojipedia.org/

	set -euo pipefail

	#!/bin/bash

	# Credit to https://gist.github.com/alisdair/ffc7c884ee36ac132131f37e3803a1fe for the excellent original
	# script that this one is based on. This script modifies the original to create the jumbo.

	# Generate a jumbo Slack emoji, given a reasonable image
	# input. I recommend grabbing an emoji from https://emojipedia.org/

	set -euo pipefail

	/**
	* Small helper script to debug via printing in WorldEdit CraftScript.
	* Save this file as debug.js in your WorldEdit config folder:
	* e.g. config/worldedit/craftscript/debug.js
	*
	* Use in the console:
	* /cs debug
	* /cs debug player
	*
	* With no arguments this script will print all globals.

	#!/bin/bash

	# Generate a `:something-party:` Slack emoji, given a reasonable image
	# input. I recommend grabbing an emoji from https://emojipedia.org/

	set -euo pipefail

	if [ $# -eq 0 ]; then
	echo "Usage: $0 input.png"
	exit 1

	<?xml version="1.0" encoding="UTF-8"?>
	<LightBurnProject AppVersion="1.6.03" FormatVersion="1" MaterialHeight="0" MirrorX="False" MirrorY="False">
	<Thumbnail Source="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

	BEGIN:VCARD
	VERSION:3.0
	FN;CHARSET=UTF-8:Better Uptime
	N;CHARSET=UTF-8:Uptime;Better;;;
	TEL;TYPE=CELL:+1 (872) 231-5748
	TEL;TYPE=CELL:+1 (872) 278-6922
	TEL;TYPE=CELL:+1 (872) 278-6921
	TEL;TYPE=HOME,VOICE:+1 (256) 485-4958
	TEL;TYPE=WORK,VOICE:+32 460 23 47 47
	ORG;CHARSET=UTF-8:BetterUptime

Lee Trout leetrout

Latency numbers every programmer should know

AWS Grok patterns for load balancer logs

Connection logs

How to easily setup PXE boot for cluster provisioning

PXE boot description