UW Advanced Rails Week 5

Transcript

1. Questions from Week 4? 1
2. Week 5: Background Jobs Spring 2015 2
3. What are Background Jobs? 3
4. What are Background Jobs? Process that are run in the background Independent from our Rails app 4
5. When should you use Background Jobs? 5
6. When should you use Background Jobs? 6
7. Long Running Requests/ Processes 7
8. Long Running Requests/ Processes HTTP requests outside of your app Image/Video Processing 8
9. Tasks to be Run at a Later Date 9
10. Tasks to be Run at a Later Date Mailers Billing Analytics Building Cleanup 10
11. How do Background Jobs Work? Queueing systems First In, First Out (FIFO) 11
12. Active Job Introduced in Rails 4 Provides an interface for queueing backends 12
13. Common Queueing Adapters Delayed Job github.com/collectiveidea/delayed_job Resque github.com/resque/resque Sidekiq http://sidekiq.org/ 13
14. Delayed Job Pros Created by Shopify Very mature product. Well maintained. Very simple to add, no external services Uses ActiveRecord for queueing 14
15. Delayed Job Cons Uses ActiveRecord for queueing Requires a separate worker to check queues No Web-ui 15
16. Resque Pros Created by Github Well maintained. Asynchronous Doesn’t use ActiveRecord Built in Web-ui Uses Redis 16
17. Resque Cons Harder to setup* Redis dependency 17
18. Sidekiq Pros Built in Web-ui Multi-threaded Uses Redis for queueing 18
19. Sidekiq Cons Harder to setup Redis dependency Thread Safety Not Guaranteed! 19
20. Using Background Jobs in Shortener 20
21. Background Jobs Welcome Email Tweeting when creating links Weekly User Stats 21
22. Adding sidekiq 22 Gemfile config/application.rb
23. Procfile with Foreman 23 Gemfile .foreman
24. Sidekiq Web View 24 Gemfile config/routes.rb
25. Sending Mail Later 25 app/controllers/users_controller.rb
26. Generate a Job 26
27. Twitter Job 27 app/controllers/links_controller.rb app/jobs/twitter_job.rb
28. Running Twitter Jobs 28 app/controllers/links_controller.rb
29. Failing Specs :( 29
30. 30 specs/controllers/users_controller_spec.rb
31. 31 app/controllers/links_controller_spec.rb
32. Cron Based Jobs 32 app/controllers/links_controller.rb config/schedule.rb
33. Cron Based Jobs 33 lib/tasks/email/weekly_tasks.rake