danvideo

class BottlesOfBeer
  def count_off
    puts "How many bottles of beer have you got? "
    numbers = gets.chomp.to_i
    numbers.downto(1) do |number|
    puts "#{number} bottles of beer on the wall, #{number} bottles of beer! Take one down, pass it around, #{number-1} bottles of beer on the wall!"   
  end
end

bottle = BottlesOfBeer.new

danvideo

require 'rest-client'
require 'json'

room_name = "INSERT_ROOM_NAME_HERE"

url = "http://tlk.io/" + room_name + "/messages"

result = RestClient.get(url)
parsed = JSON.parse result
parsed.each do |element|

danvideo

# Compiled source #
###################
*.com
*.class
*.dll
*.exe
*.o
*.so

# Packages #

danvideo

Final Projects from BEWD 5

Flash sale app                                                                     
http://intense-stream-5307.herokuapp.com/                                          

Ten Thousand Hours                                                                 
http://infinite-basin-5033.herokuapp.com                                           

Photobooth app                                                                     
http://hidden-reaches-9583.herokuapp.com/                                          

danvideo

# You don't need Fog in Ruby or some other library to upload to S3 -- shell works perfectly fine
# This is how I upload my new Sol Trader builds (http://soltrader.net)
# Based on a modified script from here: http://tmont.com/blargh/2014/1/uploading-to-s3-in-bash

S3KEY="my aws key"
S3SECRET="my aws secret" # pass these in

function putS3
{
  path=$1

danvideo

git branch -m old_branch new_branch         # Rename branch locally    
git push origin :old_branch                 # Delete the old branch    
git push --set-upstream origin new_branch   # Push the new branch, set local branch to track the new remote

danvideo

#System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

##Basic Steps

1. Clarify and agree on the scope of the system

• User cases (description of sequences of events that, taken together, lead to a system doing something useful)
  • Who is going to use it?
  • How are they going to use it?

danvideo

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        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

danvideo

global
  maxconn 4096
  pidfile /tmp/haproxy-queue.pid

defaults
  log global
  mode http
  timeout connect 300000
  timeout client 300000
  timeout server 300000

danvideo

socat - udp4-listen:8125,fork | tee >(socat - udp-sendto:127.0.0.1:8135) >(socat - udp-sendto:127.0.0.1:8140)