alex-quiterio

PSQL

Magic words:

psql -U postgres

Some interesting flags (to see all, use -h or --help depending on your psql version):

• -E: will describe the underlaying queries of the \ commands (cool for learning!)
• -l: psql will list all databases and then exit (useful if the user you connect with doesn't has a default database, like at AWS RDS)

alex-quiterio

#!/usr/bin/env bash
set -e

function usage() {
    set -e
    cat <<EOM
    ##### ecs-run #####
    Simple script for running tasks on Amazon Elastic Container Service
    One of the following is required:
    Required arguments:

alex-quiterio

# 
# Install the MYSQL driver
#   gem install mysql2
#
# Ensure the MySQL gem is defined in your Gemfile
#   gem 'mysql2'
#
# And be sure to use new-style password hashing:
#   http://dev.mysql.com/doc/refman/5.0/en/old-client.html
development:

alex-quiterio

var mediaQueryListElement = window.matchMedia("all and (min-width: 666px)");

function call_me(name) {
	console.log("És um " + name);
	mediaQueryListElement.removeListener(call_me.caller);
}

mediaQueryListElement.addListener(function() {
	call_me("sugar");
});

alex-quiterio

#!/usr/bin/env ruby
# A quick and dirty implementation of an HTTP proxy server in Ruby
# because I did not want to install anything.
# 
# Copyright (C) 2009-2014 Torsten Becker <torsten.becker@gmail.com>
# 
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,

alex-quiterio

Latency Comparison Numbers
--------------------------
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
Send 1K bytes over 1 Gbps network        10,000   ns    0.01 ms
Read 4K randomly from SSD*              150,000   ns    0.15 ms

alex-quiterio

--- module ScottsSnake where

import Keyboard
import Random
import String
import Set

type Position = {x: Int, y: Int }
type Board = {w: Int, h: Int, wall: [Position]}
type Apple = Position

alex-quiterio

Benchmarking Nginx with Go

Today I just wanted to know which of these options is faster:

• Go HTTP standalone
• Nginx proxy to Go HTTP
• Nginx fastcgi to Go TCP FastCGI
• Nginx fastcgi to Go Unix Socket FastCGI

Hardware

alex-quiterio

$VERBOSE = nil
require File.expand_path('../rooby', __FILE__)


Person = Rooby::Class.new 'Person' do
  define :initialize do |name|
    @name = name
  end
  
  define :name do

alex-quiterio

Security is Hard

Massive Assignment

• watch for ActiveRecord Relation, like has_many, has_many :through
• watch for user_roles, `group_users
• UPDATE action

Admin