1. What Every
Programmer Should
Know About
Distributed Systems
Friday, November 11, 11

2. What Every
Programmer Could
Possibly Want To Know
About Me
Friday, November 11, 11

3. Friday, November 11, 11

4. Friday, November 11, 11

5. Friday, November 11, 11

6. Friday, November 11, 11

7. What Every
Programmer Should
Know About
Distributed Systems
Friday, November 11, 11

8. I
Definition
Friday, November 11, 11

9. A distributed system
consists of multiple
autonomous applications
that interact with each other to
achieve a common goal.
Friday, November 11, 11

10. II
Code Granularity
Photo by Matt Gibson
Friday, November 11, 11

11. print "Converting Celsius or Fahrenheit? "
option = gets[0,1].downcase
case option
when "c"
print "Convert C: "
celsius = gets.to_i
fahrenheit = celsius * 9/5 + 32
puts "#{celsius}C = #{fahrenheit}F"
when "f"
print "Convert F: "
fahrenheit = gets.to_i
celsius = (fahrenheit - 32) * 5/9
puts "#{fahrenheit}F = #{celsius}C"
end
Friday, November 11, 11

12. def main
convert(pick_unit)
end
def pick_unit
print "Convert Celsius ou Fahrenheit? "
gets[0,1].downcase
end
def convert(unit)
case unit
when "c": convert_celsius
when "f": convert_fahrenheit
end
end
...
Friday, November 11, 11

13. Ideal Granularity
Somewhere in between
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14. Units & OO
• Methods
• Classes
• Packages
Friday, November 11, 11

15. Units & Languages
• Ruby # sinatra.rb
module Sinatra
• Java class Application
...
• PHP class Event
...
module Streaming
class FileStreamer
...
Friday, November 11, 11

16. Units & Languages
• Ruby
• Java
• PHP $ javac Sinatra.java
sinatra.java:5: class Application is public, should be
declared in a file named Application.java
Friday, November 11, 11

17. Units & Languages
• Ruby
• Java
• PHP
Friday, November 11, 11

18. Units & Architecture
• Applications
Friday, November 11, 11

19. III
The Evolution of Óbidos
From Google Maps
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20. Friday, November 11, 11

21. Heroku
• Instance management
• Billing & invoices
• Process orchestration
• Public API
Friday, November 11, 11

22. Heroku
• Instance management
• Billing & invoices
• Process orchestration
• Public API
Friday, November 11, 11

23. Heroku
• Instance management
• Billing & invoices
• Process orchestration
• Public API
Friday, November 11, 11

24. Heroku
• Instance management
• Billing & invoices
• Process orchestration
• Public API
Friday, November 11, 11

25. IV
Developing the Medium
Friday, November 11, 11

26. Problem:
?
Friday, November 11, 11

27. Share the Database
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28. OT
O NShare the Database
D
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29. REST
RestClient.get "host/users/1" get "/users/:id" do |id|
user = User.find(id)
user.to_json
end
Friday, November 11, 11

30. MQ
AMQP.start(:host => "1.2.3.4") do AMQP.start(:host => "1.2.3.4") do
q = MQ.new.queue("user.created") q = MQ.new.queue("user.created")
q.publish(:email => "pedro@heroku.com") q.subscribe do |msg|
end ...
end
end
Friday, November 11, 11

31. V
Challenges
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32. Challenges
• Versioning
• Testing
• Authentication
• Development environment
• Visual consistency
• Deploying
Friday, November 11, 11

33. Summary
1. Definition
2. Code Granularity
3. The Evolution of Óbidos
4. Developing the Medium
5. Challenges
Friday, November 11, 11

34. Thank you!
pedro@heroku.com
http://pedro.heroku.com
@ped
Friday, November 11, 11