[RubyWine #1] Event-Driven Architecture and Messaging Patterns for Ruby Microservices

How to choose a communication protocol for services? Synchronous vs Asynchronous approach. HTTP, Brokered Messaging and gRPC. Issues when working with Threads and asynchronous message queues in Ruby and their solutions. Logging and monitoring of transactional integrity. Publish/Subscribe messaging systems and a brief comparison of them.

Video - https://youtu.be/e9AAUy4kkek

Transcript

1. Event-Driven Architecture Event-Driven Architecture Messaging Patterns for Ruby Microservices https://bit.ly/2RSudnT Kirill Shevchenko Kirill Shevchenko
2. Who I am Who I am Ruby/JS developer, Tech Lead at
3. Who I am Who I am Ruby/JS developer, Tech Lead at Two years with Microservices
4. Who I am Who I am Ruby/JS developer, Tech Lead at Two years with Microservices Maintainer of Ruby/Rails digest on
5. Who I am Who I am Ruby/JS developer, Tech Lead at Two years with Microservices Maintainer of Ruby/Rails digest on Live in Dnipro, Ukraine
6. Who I am Who I am Ruby/JS developer, Tech Lead at Two years with Microservices Maintainer of Ruby/Rails digest on Live in Dnipro, Ukraine kirill_shevch
7. Who I am Who I am Ruby/JS developer, Tech Lead at Two years with Microservices Maintainer of Ruby/Rails digest on Live in Dnipro, Ukraine kirillshevch kirill_shevch
8. Agenda Agenda Road from Monolith to Microservices Communication Patterns Message Brokers Publish/Subscribe Testing and Monitoring
9. Microservices Are Microservices Are Something You Grow Into, Something You Grow Into, Not Begin With Not Begin With
10. Let The Adventure Let The Adventure Begin Begin
11. "Hello World" Setup "Hello World" Setup +
12. "Hello World" Setup "Hello World" Setup
13. Background Jobs Background Jobs +
14. Background Jobs Background Jobs
15. Cache Cache
16. Business logic size Business logic size Orders?
17. Business logic size Business logic size Products? Orders?
18. Business logic size Business logic size Analytics? Products? Orders?
19. Business logic size Business logic size Analytics? Products? Orders? Users?
20. Applying DDD to Microservices Applying DDD to Microservices
21. Pattern: Database Per Service Pattern: Database Per Service
22. Pattern: Database Per Service Pattern: Database Per Service
23. Pattern: Database Per Service Pattern: Database Per Service
24. Messaging Patterns Messaging Patterns
25. Sync vs Async Approach Sync vs Async Approach Two Ways Two Ways
26. Sync vs Async Approach Sync vs Async Approach Two Ways Two Ways The publisher writes a message and waits until reader confirm the reading
27. Sync vs Async Approach Sync vs Async Approach Two Ways Two Ways The publisher writes a message and waits until reader confirm the reading The writer doesn't wait for the reader, you can read the message at any time
28. Synchronous Calls Synchronous Calls Probably, easiest communication pattern to Probably, easiest communication pattern to implement is simply calling another service implement is simply calling another service synchronously, usually via REST. synchronously, usually via REST. Service 1 Service 2 REST
29. Synchronous Calls Synchronous Calls Protocols Protocols HTTP/RPC HTTP/RPC
30. Synchronous Calls Synchronous Calls Protocols Protocols HTTP/RPC HTTP/RPC except for except for streaming streaming
31. HTTP/REST IS GREAT HTTP/REST IS GREAT Easy to understand (text protocol) Web infrastructure already built on top of HTTP Great tooling for testing, inspection, modification Loose coupling between clients/server makes changes easy High-quality http implementations in every language
32. Synchronous Calls Synchronous Calls Problems? Problems? You need wait for a response You need to handle errors (like timeouts) You work with many different APIs You you use a lot of different API wrappers
33. A gem for building API Wrappers in Ruby A gem for building API Wrappers in Ruby
34. ApiStruct: Configuration ApiStruct: Configuration ApiStruct::Settings.configure do |config| config.endpoints = { some_api: { root: 'https://someapi.dev/v1' } } end
35. ApiStruct: Client ApiStruct: Client class OrdersClients < ApiStruct::Client some_api :orders def index get end def show(id) get(id) end end
36. ApiStruct: Entity ApiStruct: Entity class Order < ApiStruct::Entity client_service OrdersClient attr_entity :id, :state, :total_price end
37. ApiStruct: Entity ApiStruct: Entity class Order < ApiStruct::Entity client_service OrdersClient attr_entity :id, :state, :total_price end order = Order.show(1) # => {"id"=>1, "state"=>"shipping", "total_price"=>"99"}
38. Event-Driven Architecture Event-Driven Architecture ( (EDA EDA) )
39. Сommunication Сoncepts Сommunication Сoncepts Messages Messages Events Events Commands Commands
40. Messages Messages The basic unit of communication in Message Brokers The basic unit of communication in Message Brokers
41. Messages Messages The basic unit of communication in Message Brokers The basic unit of communication in Message Brokers Literally can be anything Literally can be anything
42. Messages Messages The basic unit of communication in Message Brokers The basic unit of communication in Message Brokers Literally can be anything Literally can be anything An ID, a string, an object, a An ID, a string, an object, a command, an event or whatever. command, an event or whatever.
43. Commands Commands It's a one-to-one communication between publisher It's a one-to-one communication between publisher and subscriber and subscriber
44. Commands Commands It's a one-to-one communication between publisher It's a one-to-one communication between publisher and subscriber and subscriber Event Publisher Subscriber
45. Events Events An event is a message which informs listeners about An event is a message which informs listeners about something which has happened something which has happened
46. Events Events An event is a message which informs listeners about An event is a message which informs listeners about something which has happened something which has happened Event Publisher Subscriber 1 Subscriber 2
47. Topic Topic Queue Queue vs
48. Topic Topic Queue Queue vs All subscribers will receive a All subscribers will receive a copy of the message copy of the message
49. All subscribers will receive a All subscribers will receive a copy of the message copy of the message A single message will be A single message will be received by exactly one received by exactly one consumer consumer Topic Topic Queue Queue vs
50. Queues Queues Pros Pros Simple messaging pattern with a transparent communication flow Messages can be recovered by putting them back on the queue
51. Cons Cons Only one consumer can get the message Implies a coupling between producer and consumer as it’s an one-to-one relation Queues Queues
52. Topics Topics Pros Pros Multiple consumers can get a message Decoupling between producer and consumers (publish-and- subscribe pattern)
53. Cons Cons More complicated communication flow A message cannot be recovered for a single listener Topics Topics
54. Virtual Topics Virtual Topics Pros Pros Multiple consumers can get a message Decoupling between producer and consumers (publish-and-subscribe pattern) Messages can be recovered by putting them back on the queue
55. Virtual Topics Virtual Topics Cons Cons Might require additional configuration in the broker
56. FIFO (First-In-First-Out) FIFO (First-In-First-Out) Queues Queues The order in which messages are sent and received is strictly preserved.
57. Message Brokers Message Brokers
58. Checklist Checklist Services discovery Messaging Load balancing Logging Queuing
59. ACTIVE Apache MQ
60. Amazon SQS Amazon SQS Fully managed message queue Fully managed message queue
61. Amazon SQS Amazon SQS Fully managed message queue Fully managed message queue Pros Pros Cons Cons
62. Amazon SQS Amazon SQS Fully managed message queue Fully managed message queue Pros Pros Available as a cloud service Cons Cons
63. Amazon SQS Amazon SQS Fully managed message queue Fully managed message queue Pros Pros Available as a cloud service Cons Cons FIFO queues support only 300 messages per second
64. Amazon SQS Amazon SQS Fully managed message queue Fully managed message queue Pros Pros Available as a cloud service Cons Cons FIFO queues support only 300 messages per second No ability to use FIFO with Pub/Sub (SNS)
65. ACTIVE Apache MQ
66. ActiveMQ ActiveMQ Pros Pros It has two main concepts: topics and queues
67. ActiveMQ ActiveMQ Pros Pros It has two main concepts: topics and queues Load Balancing: replication, horizontal scaling
68. ActiveMQ ActiveMQ Pros Pros It has two main concepts: topics and queues Load Balancing: replication, horizontal scaling Support for most protocols
69. ActiveMQ ActiveMQ Pros Pros It has two main concepts: topics and queues Load Balancing: replication, horizontal scaling Support for most protocols Cons Cons Need backups
70. ActiveMQ ActiveMQ Pros Pros It has two main concepts: topics and queues Load Balancing: replication, horizontal scaling Support for most protocols Cons Cons Need backups Might require additional configuration(FIFO, Virtual Topics)
71. Protocols Protocols
72. Protocols Protocols OpenWire OpenWire STOMP STOMP AMQP AMQP MQTT MQTT What to сhoose? What to сhoose? WebSocket WebSocket XMPP XMPP
73. ActiveMQ ActiveMQ Instance can provide Instance can provide all protocols at the all protocols at the same time same time
74. ActiveMQ ActiveMQ Endpoints Endpoints
75. Publish/Subscribe Publish/Subscribe pattern and Ruby pattern and Ruby
76. Publishing is simply Publishing is simply options = { command: 'update_order', data: { order_id: 1, state: :paid } } redis = Redis.new redis.publish(:orders, options.to_json)
77. But we need handle But we need handle pubishing result pubishing result options = { command: 'update_order', data: { order_id: 1, state: :paid } } redis = Redis.new redis.publish(:orders, options.to_json).tap do |r| Raven.capture_message('Publish failed', extra: options) if r.zero? end
78. Pub/Sub pattern Pub/Sub pattern redis = Redis.new redis.subscribe(:orders) do |on| on.message do |channel, message| # call the command end end
79. Pub/Sub pattern Pub/Sub pattern redis = Redis.new Thread.new do redis.subscribe(:orders) do |on| on.message do |channel, message| begin # call the command rescue StandardError => e Raven.capture_exception(e) end end end end
80. Testing Testing
82. Real life problems Real life problems No one really knows how to test microservices
83. Real life problems Real life problems No one really knows how to test microservices No one really knows how to test infrastructure for microservices
84. Solutions? Solutions? Unit testing for each service with hard mocking
85. Solutions? Solutions? Unit testing for each service with hard mocking Up the server with all services for running integration testing
86. Monitoring Monitoring No more single system, no more centralized monitoring
87. Monitoring Monitoring No more single system, no more centralized monitoring Logs and metrics collecting (Beats, Statsd, Elasticsearch)
88. Monitoring Monitoring No more single system, no more centralized monitoring Logs and metrics collecting (Beats, Statsd, Elasticsearch) Aggregation (Logstash)
89. Monitoring Monitoring No more single system, no more centralized monitoring Logs and metrics collecting (Beats, Statsd, Elasticsearch) Aggregation (Logstash) Visualization (Kibana, Grafana)
90. Monitoring Monitoring No more single system, no more centralized monitoring Logs and metrics collecting (Beats, Statsd, Elasticsearch) Aggregation (Logstash) Visualization (Kibana, Grafana) Store and maintain all this data and systems
91. Thanks! Thanks!