Taming Monoliths without Microservices - RubyConf AU 2019

https://kellysutton.com/2019/02/07/taming-monoliths-without-microservices-rubyconf-au.html

Transcript

1. TAMING MONOLITHS WITHOUT MICROSERVICES Kelly Sutton — Rubyconf AU 2019
2. Overview I. About Me II. Breaking the Monolith III. Tactics IV. Wrap Up kellysutton.com
3. Part I: About Me
4. About Me
5. About Greta
6. About Greta
7. About Greta
8. About Greta
9. But that’s not why we’re here kellysutton.com
10. We’re here to talk about Rails projects that push the limits kellysutton.com
11. kellysutton.com
12. Time Geography Money People kellysutton.com
13. Correctness > Performance kellysutton.com
14. What goes wrong, when things get too big kellysutton.com
15. Part II: Breaking the Monolith
16. The Swamp kellysutton.com
18. kellysutton.com
19. kellysutton.com
20. The Swamp Payroll HR Benefits Infra kellysutton.com
21. “Let’s Extract a Service!” kellysutton.com
22. Photo by Thomas Halfmann kellysutton.com
23. The Swamp Payroll HR Benefits Infra kellysutton.com
24. The Swamp Payroll HR Benefits Infra kellysutton.com
25. The Swamp Payroll HR Benefits Infra HR v2 kellysutton.com
26. The Swamp Payroll HR Benefits Infra HR v2 kellysutton.com
27. The Swamp Payroll Old HR Benefits Infra HR v2 kellysutton.com
28. But there is a better way
29. kellysutton.com
30. Employee HR Payroll kellysutton.com
31. Employee HR Payroll kellysutton.com
32. Employee HR Payroll employee.last_name kellysutton.com
33. HR Payroll kellysutton.com
34. HR Payroll kellysutton.com
35. HR Payroll Employee PayrollEmployee kellysutton.com
36. HR Payroll Employee PayrollEmployee kellysutton.com
37. HR Payroll Employee PayrollEmployee payroll_employee.last_name kellysutton.com
38. HR Payroll kellysutton.com
39. HR Payroll kellysutton.com
40. Value Objects HR Payroll kellysutton.com
41. Conceptual Compression
42. Conceptual Expansion
43. Part III: Tactics
44. Recommendation #1 Mind and Avoid Circular Dependencies kellysutton.com
45. As your Rails code base grows, question bidirectional relationships kellysutton.com
46. 1 # app/models/company.rb 2 class Company < ApplicationRecord 3 has_many :employees 4 end 5 6 # app/models/employee.rb 7 class Employee < ApplicationRecord 8 belongs_to :company 9 end kellysutton.com
47. 1 # app/models/company.rb 2 class Company < ApplicationRecord 3 has_many :employees 4 end 5 6 # app/models/employee.rb 7 class Employee < ApplicationRecord 8 belongs_to :company 9 end Do we need this? kellysutton.com
48. Company Employee kellysutton.com
49. Company Employee kellysutton.com
50. Recommendation #2 Use Value Objects to Traverse Edges kellysutton.com
51. 1 # app/services/company_signed_up.rb 2 class CompanySignedUp 3 def self.call(company) 4 CompanyMailer.welcome_email(company) 5 StatsTracker.company_signed_up(company) 6 end 7 end kellysutton.com
52. 1 # app/services/company_signed_up.rb 2 class CompanySignedUp 3 def self.call(company) 4 user_first_name = company.admin_first_name 5 email = company.admin_email 6 7 CompanyMailer.welcome_email(email, user_first_name) 8 StatsTracker.company_signed_up(company.id) 9 end 10 end kellysutton.com
53. Recommendation #3 Avoid Callbacks kellysutton.com
54. 1 # app/models/company.rb 2 class Company < ApplicationRecord 3 after_create :send_update_email, if: :has_email? 4 5 private 6 7 def send_update_email 8 CompanyMailer.welcome_email(self) 9 end 10 end kellysutton.com
55. Company CompanyMailer kellysutton.com
56. 1 # app/services/create_company.rb 2 class CreateCompany 3 def self.call(company_params) 4 company = Company.create!(company_params) 5 6 CompanyMailer.welcome_email(company) 7 end 8 end kellysutton.com
57. Company CompanyMailer CreateCompany kellysutton.com
58. Recommendation #4 Move slowly! kellysutton.com
59. Part IV: Wrap Up kellysutton.com
60. –Kent Beck “Make the hard change easy (this may be hard), then make the easy change.” kellysutton.com
61. Thanks! Slides and more available at kellysutton.com
62. References • Bernhardt, Gary. “Boundaries.” 2012. • Bernhardt, Gary. “Functional Core, Imperative Shell.” 2012. • Evans, Eric. “Domain-Driven Design: Tackling Complexity in the Heart of Software.” 2003. • Fowler, Martin, et al. “Refactoring: Improving the Design of Existing Code.” 1999. • Feathers, Michael. “Working Effectively with Legacy Code.” 2004. • Hickey, Rich. “Simple Made Easy.” 2011. • Hickey, Rich. “The Value of Values.” 2012. • Scott, James C. “Seeing Like a State.” 1999. • Searls, Justin. “My Preferred Method of TDD.” 2017 • Spolsky, Joel. “Things You Should Never Do, Part I.” 2006.
63. Special Thanks • Noa Elad • Matan Zruya • Sihui Huang • Natalie Wong • Karlo Hoa • Amelie Meyer-Robinson • Quentin Balin