Oliver Mannion tekumara

Internet Scale Services Checklist

A checklist for designing and developing internet scale services, inspired by James Hamilton's 2007 paper "On Desgining and Deploying Internet-Scale Services."

http://mvdirona.com/jrh/talksandpapers/jamesrh_lisa.pdf

Basic tenets

Does the design expect failures to happen regularly and handle them gracefully?
Have we kept things as simple as possible?

Basic diffing

Line by line
No colors
Able to be piped into vim (shown later on)

diff <(curl -vs https://reddit.com 2>&1) <(curl -vs https://reddit.com 2>&1)

What is the appeal of dynamically-typed languages?

Kris Nuttycombe asks:

I genuinely wish I understood the appeal of unityped languages better. Can someone who really knows both well-typed and unityped explain?

I think the terms well-typed and unityped are a bit of question-begging here (you might as well say good-typed versus bad-typed), so instead I will say statically-typed and dynamically-typed.

I'm going to approach this article using Scala to stand-in for static typing and Python for dynamic typing. I feel like I am credibly proficient both languages: I don't currently write a lot of Python, but I still have affection for the language, and have probably written hundreds of thousands of lines of Python code over the years.

HTTP Streaming (or Chunked vs Store & Forward)

The standard way of understanding the HTTP protocol is via the request reply pattern. Each HTTP transaction consists of a finitely bounded HTTP request and a finitely bounded HTTP response.

However it's also possible for both parts of an HTTP 1.1 transaction to stream their possibly infinitely bounded data. The advantages is that the sender can send data that is beyond the sender's memory limit, and the receiver can act on

Using py.test is great and the support for test fixtures is pretty awesome. However, in order to share your fixtures across your entire module, py.test suggests you define all your fixtures within one single conftest.py file. This is impractical if you have a large quantity of fixtures -- for better organization and readibility, you would much rather define your fixtures across multiple, well-named files. But how do you do that? ...No one on the internet seemed to know.

Turns out, however, you can define fixtures in individual files like this:

tests/fixtures/add.py

import pytest

@pytest.fixture

Setup

Add this to your .profile, .bashrc, .zshrc...

decode_base64_url() {
  local len=$((${#1} % 4))
  local result="$1"
  if [ $len -eq 2 ]; then result="$1"'=='
  elif [ $len -eq 3 ]; then result="$1"'=' 
  fi
 echo "$result" | tr '_-' '/+' | openssl enc -d -base64

	" A minimal vimrc for new vim users to start with.
	"
	" Referenced here: http://www.benorenstein.com/blog/your-first-vimrc-should-be-nearly-empty/

	" Original Author: Bram Moolenaar <[email protected]>
	" Made more minimal by: Ben Orenstein
	" Last change: 2012 Jan 20
	"
	" To use it, copy it to
	" for Unix and OS/2: ~/.vimrc

	#!/bin/bash

	function test {
	MESSAGE=$1
	RECEIVED=$2
	EXPECTED=$3

	if [ "$RECEIVED" = "$EXPECTED" ]; then
	echo -e "\033[32m✔︎ Tested $MESSAGE"
	else

	# On slow systems, checking the cached .zcompdump file to see if it must be
	# regenerated adds a noticable delay to zsh startup. This little hack restricts
	# it to once a day. It should be pasted into your own completion file.
	#
	# The globbing is a little complicated here:
	# - '#q' is an explicit glob qualifier that makes globbing work within zsh's [[ ]] construct.
	# - 'N' makes the glob pattern evaluate to nothing when it doesn't match (rather than throw a globbing error)
	# - '.' matches "regular files"
	# - 'mh+24' matches files (or directories or whatever) that are older than 24 hours.
	autoload -Uz compinit

	#!/bin/sh

	### Desktop & Screen Saver

	# Desktopを黒に
	echo "Change Desctop Pictures"
	osascript -e 'tell application "Finder" to set desktop picture to POSIX file "/Library/Desktop Pictures/Solid Colors/Black.png"'

	# ScreenSaver Kill
	echo "Disable screensaver"