Javier García manzanit0

Don't use VPN services.

No, seriously, don't. You're probably reading this because you've asked what VPN service to use, and this is the answer.

Note: The content in this post does not apply to using VPN for their intended purpose; that is, as a virtual private (internal) network. It only applies to using it as a glorified proxy, which is what every third-party "VPN provider" does.

A Russian translation of this article can be found here, contributed by Timur Demin.
A Turkish translation can be found here, contributed by agyild.
There's also this article about VPN services, which is honestly better written (and has more cat pictures!) than my article.

Uber facts

Original posts/information

Migrating Uber from MySQL to PostgreSQL

Key points

~50GB MySQL Application
Main motivation: PostGis
Migration made with a custom tool(xml2pgcopy) and mysqldump on 45min

Code is clean if it can be understood easily – by everyone on the team. Clean code can be read and enhanced by a developer other than its original author. With understandability comes readability, changeability, extensibility and maintainability.

General rules

Follow standard conventions.
Keep it simple stupid. Simpler is always better. Reduce complexity as much as possible.
Boy scout rule. Leave the campground cleaner than you found it.
Always find root cause. Always look for the root cause of a problem.

	-- show running queries (pre 9.2)
	SELECT procpid, age(clock_timestamp(), query_start), usename, current_query
	FROM pg_stat_activity
	WHERE current_query != '<IDLE>' AND current_query NOT ILIKE '%pg_stat_activity%'
	ORDER BY query_start desc;

	-- show running queries (9.2)
	SELECT pid, age(clock_timestamp(), query_start), usename, query
	FROM pg_stat_activity
	WHERE query != '<IDLE>' AND query NOT ILIKE '%pg_stat_activity%'

	sudo wget http://repos.fedorapeople.org/repos/dchen/apache-maven/epel-apache-maven.repo -O /etc/yum.repos.d/epel-apache-maven.repo
	sudo sed -i s/\$releasever/6/g /etc/yum.repos.d/epel-apache-maven.repo
	sudo yum install -y apache-maven
	mvn --version

	--- Actions ---
	$Copy <M-C>
	$Cut <M-X> <S-Del>
	$Delete <Del> <BS> <M-BS>
	$LRU
	$Paste <M-V>
	$Redo <M-S-Z> <A-S-BS>
	$SearchWeb <A-S-G>
	$SelectAll <M-A>
	$Undo <M-Z>

	iex(2)> pid = spawn Traps, :init, []
	waiting to die...
	#PID<0.92.0>
	Nobody tried to kill me! ^_^
	waiting to die...
	Nobody tried to kill me! ^_^
	waiting to die...
	iex(3)> Process.exit pid, :normal
	true
	(⊙＿⊙') somebody tried to kill me! {:EXIT, #PID<0.88.0>, :normal}

	<!DOCTYPE html>
	<html>

	<head>
	<meta charset="utf-8">
	<title></title>
	<meta name="author" content="">
	<meta name="description" content="">
	<meta name="viewport" content="width=device-width, initial-scale=1">

	defmodule Map.Helpers do
	@moduledoc """
	Functions to transform maps
	"""

	@doc """
	Convert map string camelCase keys to underscore_keys
	"""
	def underscore_keys(nil), do: nil

	defmodule YourApp.Validators.Email do
	use Ecto.Changeset
	@mail_regex ~r/^[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]{2,4}$/
	# ensure that the email looks valid
	def validate_email(changeset, field) do
	changeset
	\|> validate_format(field, @mail_regex)
	end
	end