1. Large Scale Ruby Project, Challenges
and Pitfalls
● Karunakar Revuri
● Castle Rock Research
● Rails Contributor
● @karuna_revuri
● https://github.com/Karunakar

2. Ruby Project
● Code
● Tests
● Performance

3. Test Driven Development

4. Good
● My_code has_many units and functionals
● Thoughtbot-shoulda

5. Bad
● Test suite is taking more than 45 mins

6. Why?
● Many tests
● Bad Tests
● Unnecessary objects
● Unnecessary tests
● Tests with assert true
● Tests with !assert failure
● Big tests
● Random failure tests

7. Solution
● Cleanup
● Mock your objects when needed
● Run tests in parallel

8. DEMO

9. Behavior Driven Development
FRAMEWORK
● Cucumber-capybara
GOOD
MyCode has many scenarios
BAD
● Cucumber is slow because of selenium

10. Selenium
● Running selenium with cucumber can eat up lot of time.
● Build time reached more than 3 hours

11. Solutions
● @rack_test
● Parallel processes

12. BORG
A Distributed Test Suite Runner for Rails
-- Hemant Kumar and Karunakar
● Eventmachine is fast, simple eventmachine processing lib
● Redis is advanced key value storage

13. How BORG works?
Developer
Machine-1
Borg Server
Developer
Machine-2
Cruise
Machine
Developer
Redis Machine-3
Server

14. BORG Supports
● Shoulda on MRI with rails
● Cucumber on MRI with rails
● Rake::Test on MRI with rails
● Rspec on MRI with rails
Works with 1.8.7 and 1.9.1, 1.9.2 with rails2x and 3x
https://github.com/Karunakar/borg
https://github.com/gnufied/borg

15. GOOD and BAD
GOOD
● Fast build
● Devs spend less time waiting to checkin
BAD
● Developer machines
● Test Splitting

16. Code Coverage Tools
● Simple Cov 1.9
● Rcov 1.8

17. Continuous Integration
● Continuous processes of applying quality
● Reduce the time to deliver
● Build

18. Continuous Integration
● Continuous processes of applying quality
● Reduce the time to deliver
● Build

20. Code Quality
● Pair programming
● Code review

21. Pairing Environment

22. Advantages
● Code is clean
● Bugs are less
● More than one will be familiar with code
● Sharing the knowledge is easy
● Good Learning curve
● Maintaining the code quality

23. Disadvantages
● Active vs Passive
● Communication between the pairs
Solutions
Switch the pairs frequently

24. Code Reviews
● Code review helps spread information about a project
between team members
● Allows people to suggest ideas and help clarify code
● Its a good time to implement some small refactoring, as
soon as problems are found
● Works best with small groups

25. Statistical Code Analysis
Statistics of code without actually executing code

26. rake stats

27. Code Smell using REEK
● Duplicate Code
● Long Method
● Large Class
● Simulated Polymorphism

28. Performance Improvements
● Internal quality
● External quality (External quality is end user happiness)

29. Performance Tools
● Bullet
● Rails indexes
● NewRelic
● Oink

30. Demo on Bullet

31. Rails Indexes Demo

32. Oink
● Memory usage in rails applications
● Memory and active record instantiation information

33. Oink
2012-03-25T03:45:15+00:00 app[web.2]: Oink Action:
sessions#new
2012-03-25T03:45:15+00:00 app[web.2]: Memory usage:
500408 | PID: 3
2012-03-25T03:45:15+00:00 app[web.2]: Instantiation
Breakdown: Total: 13 | RegionalOption: 8 | Region: 3 |
Country: 2

34. New Relic
● Performance management tool
● Slow web transactions
● Database hits and queries
● Slow web pages
● What are the reasons

35. Optimization
● Find with select
● Eager loading
● Use active-reload in development
● Use ActiveRecord to_xml instead of the xml_bulders
● Validations when needed
● Use memcache
● Use query-analyzer in development

36. Optimization
● Iterators
● Explain command
● Error notifier

37. Client Side
● Asset pipelining
● Load the js at the end of the file
● Valid HTML / XHTML

38. Thanks

39. Questions