There is no such thing as a microservice! (oracle code nyc)
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The document presents a detailed exploration of microservice architecture, contrasting it with monolithic architecture and emphasizing the importance of non-functional requirements. It outlines characteristics, benefits, and challenges of microservices, along with guidelines for effective implementation and common patterns. The author, Chris Richardson, advocates for microservices as a means to enhance software maintainability, scalability, and deployment efficiency.
There is no such thing as a microservice! (oracle code nyc)
- 1. @crichardson There is no such thing as a microservice! Chris Richardson Founder of Eventuate.io Founder of the original CloudFoundry.com Author of POJOs in Action @crichardson chris@chrisrichardson.net http://microservices.io http://eventuate.io http://plainoldobjects.com Copyright © 2017. Chris Richardson Consulting, Inc. All rights reserved
- 2. @crichardson Presentation goal Define the Microservice Architecture as an architectural style Explain what that means and why it matters
- 4. @crichardson About Chris Consultant and trainer focusing on modern application architectures including microservices (http://www.chrisrichardson.net/)
- 5. @crichardson About Chris Founder of a startup that is creating an open-source/SaaS platform that simplifies the development of transactional microservices (http://eventuate.io)
- 8. @crichardson Agenda A brief refresher on software architecture From monolith to microservices Microservices != silver bullet Managing distributed data
- 9. About software architecture “The software architecture of a computing system is the set of structures needed to reason about the system, which comprise software elements, relations among them, and properties of both.” Documenting Software Architectures, Bass et al
- 12. @crichardson Architecture is multi-dimensional e.g. Structural, electrical, plumbing, mechanical Described by multiple views View = (elements, relations, properties)
- 14. 4+1 Logical view Logical View Process View Deployment View Implementation View Scenarios Elements: classes and packages Relations: inheritance, associations, …
- 15. 4+1 Implementation view Logical View Process View Deployment View Implementation View Scenarios Elements: modules and components Relations: dependencies
- 16. 4+1 Process view Logical View Process View Deployment View Implementation View Scenarios Elements: processes Relations: IPC
- 17. 4+1 Deployment view Logical View Process View Deployment View Implementation View Scenarios Elements: “machines” Relations: networking
- 18. 4+1 Scenarios Logical View Process View Deployment View Implementation View Scenarios Derived from use cases/stories Animate the views
- 19. @crichardson ""… An architectural style determines the vocabulary of components and connectors that can be used in instances of that style, together with a set of constraints on how they can be combined….. ”” David Garlan and Mary Shaw, An Introduction to Software Architecture
- 20. @crichardson Layered architectural style Layer N Layer N - 1 Layer N - 2 Well defined responsibilities
- 21. The role of architecture Requirements = Functional requirements + Non-functional requirements (-ilities) Domain knowledge Architecture
- 23. @crichardson Businesses must innovate faster Build better software faster
- 24. @crichardson Reducing lead time Increasing deployment frequency
- 25. @crichardson Modern software development Architecture: Process: Small, autonomous teams ??? Continuous delivery/deployment Organization:
- 26. Agenda A brief refresher on software architecture From monolith to microservices Microservices != silver bullet Managing distributed data
- 27. @crichardson Tomcat/App. Server Traditional: Monolithic architecture Browser/ Client WAR/EAR MySQL Database Review Module Catalog Module Recommendation Module StoreFrontUI Order Module HTML REST/JSON Logical view
- 28. @crichardson The monolithic architecture is an architectural style that structures the application as a single executable component Implementation view
- 29. -ilities of small monoliths Maintainability Evolvability Testability Deployability Scalability … https://en.wikipedia.org/wiki/Non-functional_requirement 😄
- 30. @crichardson But successful applications keep growing…. Development Team Application
- 31. @crichardson … and growing Development Team A ApplicationDevelopment Team B Development Team C
- 33. @crichardson Technology stack becomes increasingly obsolete BUT A rewrite is not feasible
- 34. -ilities of large monoliths Maintainability Evolvability Testability Deployability … https://en.wikipedia.org/wiki/Non-functional_requirement 😭
- 35. The microservice architecture is an architectural style that structures an application as a set of loosely coupled, services organized around business capabilities Implementation view
- 36. @crichardson A business has a business capabilities Acme, Inc Order Taking Inventory management Delivery management A Business Capability is something a business does in order to deliver value …
- 37. @crichardson Service = business capability Order Taking Service Inventory management Service Delivery management Service … Service
- 38. Service size is secondary microservice architecture
- 39. Service: Meaningful business functionality Developed by a small team Minimal lead time/high deployment frequency
- 40. Microservices = Microservice architecture = Application architecture No such thing as a microservice
- 41. @crichardson Example microservice architecture Browser Mobile Device Store Front Web App API Gateway Catalog Service Review Service Order Service … Service Catalog Database Review Database Order Database … Database HTML REST REST Supplier Inbound Gateway Catalog update messages Supplier System
- 42. -ilities of a microservice architecture Maintainability Evolvability Testability Deployability Scalability … https://en.wikipedia.org/wiki/Non-functional_requirement 😄
- 43. @crichardson Microservices enable continuous delivery/deployment Process: Continuous delivery/deployment Organization: Small, agile, autonomous, cross functional teams Architecture: Microservice architecture Enables Enables Enables Successful Software Development Services improve testability and deployability Teams own services
- 44. @crichardson Evolve the technology stack Pick a new technology when Writing a new service Making major changes to an existing service Let’s you experiment and fail safely
- 45. @crichardson Agenda A brief refresher on software architecture From monolith to microservices Microservices != silver bullet Managing distributed data
- 47. @crichardson Drawbacks of microservices Complexity Development: partial failure, distributed data Testing: Integration, end to end, … Deployment …
- 48. @crichardson Are microservices a good fit for my application?
- 49. @crichardson When using microservices: How to decompose an application into services? How to deploy an application’s services? How to handle cross cutting concerns? Which communication mechanisms to use? How do external clients communicate with the services? How does a client discover the network location of a service instance? How to prevent a network or service failure from cascading to other services? How to maintain data consistency and implement queries? How to make testing easier? How to understand the behavior of an application and troubleshoot problems? How to implement a UI screen or page that displays data from multiple services?
- 51. @crichardson What’s a pattern? Reusable solution to a problem occurring in a particular context
- 52. @crichardson The structure of a pattern Resulting context aka the situation Name Context Problem Related patterns (conflicting) issues etc to address Forces Solution
- 53. @crichardson Example resulting context Microservice Architecture Benefits Drawbacks Issues to resolve
- 54. @crichardsonMicroservice patterns Communication patterns Core Cross-cutting concerns Security Deployment Maintaining data consistency Database architecture External API Reliability Discovery Communication style Testing Observability UI Decomposition API gateway Client-side discovery Server-side discovery Service registry Self registration 3rd party registration Multiple Services per host Single Service per Host Service-per- Container Service-per-VM Messaging Remote Procedure Invocation Database per Service Event-driven architectureShared database Microservice Chassis Backend for front end Event sourcing Transaction log tailing Database triggers Application events Monolithic architecture Microservice architecture CQRS Motivating Pattern Solution Pattern Solution A Solution B General Specific Serverless deployment Circuit BreakerAccess Token Domain-specific Externalized configuration Service Integration Contract Test Service Component Test Exception tracking Distributed tracing Audit logging Application metrics Log aggregation Health check API Service deployment platform Server-side page fragment composition Client-side UI composition Decompose by business capability Decompose by subdomain Application patterns Infrastructure patterns Application Infrastructure patterns Microservices pattern language: http://microservices.io
- 55. @crichardson Agenda A brief refresher on software architecture From monolith to microservices Microservices != silver bullet Managing distributed data
- 56. @crichardson Loose coupling = encapsulated data Order Service Customer Service Order Database Customer Database Order table Customer table orderTotal creditLimit
- 57. @crichardson How to enforce credit limit? sum(order.total) <= customer.creditLimit
- 58. @crichardson How to enforce credit limit? BEGIN TRANSACTION … SELECT ORDER_TOTAL FROM ORDERS WHERE CUSTOMER_ID = ? … SELECT CREDIT_LIMIT FROM CUSTOMERS WHERE CUSTOMER_ID = ? … INSERT INTO ORDERS … … COMMIT TRANSACTION Private to the Order Service Private to the Customer Service Distributed transactions
- 59. @crichardson 2PC is not an option
- 60. @crichardson Saga Instead: use event-driven sagas Distributed transaction Order Customer Local transaction Order Local transaction Customer Local transaction Order Event Event
- 61. @crichardson Order Service Saga-based, eventually consistent order processing Customer Service Order created Credit Reserved Credit Check Failed Create Order OR Customer creditLimit creditReservations ... Order state total … approve()/reject() Event Handler Event Handler reserveCredit()
- 62. @crichardson But how to reliably update the database and publish events?
- 63. @crichardson Event sourcing: event-centric persistence Event table Entity type Event id Entity id Event data Order 902101 …OrderApproved Order 903101 …OrderShipped Event type Order 901101 …OrderCreated
- 64. @crichardson How to find recent, valuable customers? SELECT * FROM CUSTOMER c, ORDER o WHERE c.id = o.ID AND o.ORDER_TOTAL > 100000 AND o.STATE = 'SHIPPED' AND c.CREATION_DATE > ? Customer Service Order Service What if event sourcing is used?…. is no longer easy
- 65. @crichardson Command Query Responsibility Segregation (CQRS) Command side Commands Aggregate Event Store Events Query side Queries (Materialized) View Events POST PUT DELETE GET
- 66. @crichardson Queries database (type) Command side POST PUT DELETE Aggregate Event Store Events Query side GET /customers/id MongoDB Query side GET /orders?text=xyz ElasticSearch Query side GET … Neo4j
- 67. @crichardson Summary The goal of architecture is to satisfy non-functional requirements Use the appropriate architectural style Small applications Monolithic architecture Complex applications Microservice architecture Use the pattern language to guide your decision making Use an event-driven architecture for transactions and queries