Микросервисы. Мифы и суровая реальность

Разговоры о микросервисах уже всех порядком достали. Много литературы, докладов и обсуждений, но все кажется оторвано от реальности – половина статей слащаво-приторно заискивающие, а остальные – полны ненависти.

Но есть суровая реальность. Мы два года работаем над переходом Gett от монолитного приложения к микросервисной архитектуре. Gett – международный сервис заказа такси и курьерской доставки, работающий в семидесяти городах и четырех странах. За это время мы столкнулись со множеством проблем, как технических так и организационных. Мой доклад будет посвящен этим проблемах и их решениям.

В докладе я буду развенчивать мифы идеальных микросервисов и рассказывать про разработку в условиях распределенной команды. Также я расскажу какие техники, практики и инструменты мы применяем в боевом коде с учетом специфики разработки на Ruby.

Transcript

1. BRUG 2016 Microservices: 
 myths and true Andrey Deryabin
2. Team Lead Andrey Deryabin
4. Taxi Beauty Home Services Food Delivery 10+ million users 80+ cities
5. James Hughes April 29, 2013 “Microservice Architecture is an architectural concept that aims to decouple a solution by decomposing functionality into discrete services”
6. Sam Newman “Microservices are small, autonomous services that work together”
7. Google Trends
8. Myth: Any language and any platform
9. Theory
10. Practice
11. Reason – Problem with HR – Corporate standard – Сomplicated Support (shared code, compatibility)
12. curl http://example.com/status { “now”:1478811001, "status":"ok", “git_revision":"6ad49a76646962ccc4362123f832ef74341f978e" } Compatibility
13. Myth: Independent Development
14. Theory
15. Practice
16. Shared code – Layout – API Client – Global Configurator – Common endpoints - Authoring system
17. Shared code – Gems – Separate private github repository
18. Shared code github 'gettservices/common', branch: 'master' do gem 'gett-api' gem 'gett-auth' gem 'gett-config' gem 'gett-ops' gem 'gett-ui' end
19. Common layout # app/views/layouts/application.slim = content_for :head do = stylesheet_link_tag 'application', media: 'all' = javascript_include_tag 'application' = csrf_meta_tags = render file: 'layouts/gett'
20. Common layout # gett-ui/app/views/layouts/gett.slim doctype html head meta charset='UTF-8' title= "Gett" = stylesheet_link_tag 'ui', media: 'all' = javascript_include_tag 'ui' = yield :head = csrf_meta_tags = favicon_link_tag body data=body_data = yield :end_of_body
21. Common settings # config/global.yml global: api: open_timeout: 5 read_timeout: 5 env: US: map_engine: 'google' distance_unit: 'imperial' time_zone: 'Pacific Time (US & Canada)' user_languages: - en-GB - en-US endpoints: user_service: hostname: user.gettservices.com ops: airbrake_api_key: 'xxx'
22. Common settings - `config/settings/base.yml` - used first in any environment - `config/settings/development_or_test.yml` - used in development or test - `config/settings/#{Rails.env}.yml` - used in Rails.env - `config/settings/developer.yml` - developer-specific settings
23. Common settings Settings.global.api => #<RailsConfig::Options open_timeout=5, read_timeout=5, write_timeout=5, open_timeout_retries=3> Settings.global.env => #<RailsConfig::Options US=#<RailsConfig::Options currency="USD", map_center_lat=39.08202, map_center_lng=-94.62726, map_engine="google", distance_unit="imperial", time_zone="Pacific Time (US & Canada)", user_languages=["en-GB", "en-US"]>
24. API client – HTTP client – Circuit Breaker – Monitoring
25. Closed Open Half open Timeout reset Success Failure Threshold reached Success Circuit Breaker
26. Circuit Breaker require 'stoplight' stoplight = Stoplight('ping') { ping 'brug.ru' } stoplight.run # => true stoplight.color # => “green" ############## stoplight.run # => false stoplight.color # => "red"
27. API client class Api::User < Api::Endpoint endpoint :user_service def self.find(env:, id:, &block) raise ArgumentError if id.blank? new get "#{env}/users/#{id}", &block end def self.all(env:, &block) wrap get "#{env}/users", &block end end Api::User.all(env: "RU")
28. Interservice Communication – Service Discovery (RPC Style) – Message Bus (Event-driven) – Hybrid
29. Interservice Communication "some_service": { "publish": ["coupon_activated", "coupons_redeemed"], "subscribe": [ { "type": "redeem_max_amount", "retry": [60, 120, 300, 600]} ] }
30. Myth: Easy Testing
31. Testing – Validating JSON Schema – Documentation – UI for live testing (Swagger integration)
32. Local Server Staging Server QA Server Production Testing workflow
33. Complication
34. Versioning/Auditing
35. A B C D
36. Two phase commit 1. Voting Phase • Coordinator sends a can_commit? request to all participants • Each participant votes YES/NO to coordinator 2. Completion Phase • Coordinator collects votes and makes the decision • YES Participants wait for a commit! or abort! request.
37. A B C D
38. A B C D check check check
39. A B C D check check check
40. A B C D check check check
41. A B C D check check check confirmation confirmation confirmation
42. A B C D check check check confirmation confirmation confirmation
43. A B C D check check check confirmation confirmation confirmation
44. A B C D check check check confirmation confirmation confirmation
45. — Mia Hamm “Failure happens all the time. It happens every day in practice. What makes you better is how you react to it”
46. Setup/Deployment
47. Monitoring
48. Release it!
49. http://bit.ly/Lurker http://bit.ly/ReleaseIt http://bit.ly/BuildingMicroservices http://microservices.io/
50. Thanks! aderyabin @aderyabin @evilmartians evilmartians.com ad@evl.ms
51. http://cultofmartians.com