Eventgetriebene Architekturen - Einführung in CQRS/ES mit Axon & Spring Boot

Die Folien des CQRS und Event Sourcing Workshops auf dem Java Forum Stuttgart Workshop Tag 2023

Transcript

1. 1 @qimono on Pixabay Eventgetriebene Architekturen Einführung in CQRS/ES mit Axon & Spring Boot Frank Steimle Nikolai Neugebauer
2. 2 Goals After this workshop you’ll know: 1. Foundations of CQRS/ES a. Components of this architectural style b. Pros and cons 2. Foundations of Axon Framework a. Programming model and components b. Test-driven development with Axon Photo by Afif Kusuma on Unsplash
3. 3 Agenda Introduction to CQRS/ES Overview Axon Practical Axon Demonstration Group Coding / Individual Coding Photo by Matthew Smith on Unsplash
4. 4 Challenges of 3-tier Architectures R ead W rite Auditability domain model data store API message queue
5. 5 Challenges of 3-tier Architectures R ead W rite Auditability domain model data store API We need to track users’ data access for compliance reasons. message queue
6. 6 Challenges of 3-tier Architectures R ead W rite Auditability domain model data store API We need to apply stronger business rules. message queue
7. 7 Challenges of 3-tier Architectures R ead W rite Auditability domain model data store API message queue We need to support mobile apps in addition to our web app.
8. 8 Challenges of 3-tier Architectures R ead W rite Auditability domain model data store API message queue Management wants business dashboards.
9. 9 Command Query Responsibility Segregation (CQRS) single model Commands (Write) Queries (Read) data store ? write model Commands (Write) Queries (Read) read model data store data store projection(s)
10. 10 CQRS & Event Sourcing (ES) write model Commands (Write) Queries (Read) read model event store
11. 11 CQRS & Event Sourcing (ES) R ead W rite Auditability events event store API message queue write model read model CQRS Event Sourcing
12. 12 1. Open-Source “CQRS/ES Framework” for the JVM a. Java/Kotlin Support b. Spring Boot Auto-Configuration c. Reactive Support d. Distributed Tracing Support e. Metrics Extensions 2. Building Blocks for CQRS / Event Sourcing a. Commands b. Events c. Queries 3. Event-Store / Event Sourcing a. Embedded Mode using SQL-Database b. Axon Server c. AxonIQ Cloud 4. Current Version: 4.8 Axon Framework
13. 13 CQRS/ES with Axon write model Commands (Write) Queries (Read) read model event store Aggregate E C Event Handler data store E Event Handler message queue E message queue REST API Q E Commands (Write) write model Queries (Read) read model
14. 14 Hexagonal Architecture (Ports & Adapters) Domain Web App Database REST Controller Database Projector Event Subscription Message Bus Mail Notification Processing Client (REST) Analytics Analytics Data C C E E E E Domain Test(s) Adapter Test(s) Other App
15. 15 Example Project: Library Management Application https://github.com/dxfrontiers/axon-library
16. 16 Command Side: Aggregate, Commands & Events Aggregate Message Queue REST API Event Store Event Event Event Sourcing Command Command
17. 17 Live Coding Photo by David Schultz on Unsplash Aggregates, Commands, Events https://github.com/dxfrontiers/axon-library #WirStellenEin
18. 18 Query Side: Event Handler, Query Handler & Queries Aggregate Event Event Handler DB Event Handler Event Handler Event Message Queue Query Handler Query Event Handler Projector
19. 19 Live Coding Photo by David Schultz on Unsplash Specialized Read Model via Event Handlers https://github.com/dxfrontiers/axon-library #WirStellenEin
20. 20 Q&A Eventgetriebene Architekturen Einführung in CQRS/ES mit Axon & Spring Boot Nikolai Neugebauer @nik101010 nikolai.neugebauer@digitalfrontiers.de Frank Steimle frank.steimle@digitalfrontiers.de https://github.com/dxfrontiers https://blog.digitalfrontiers.de @dxfrontiers https://www.youtube.com/channel/UCZfJc3Y9YO_8i5POMOZ4ktw
21. 21 • https://www.doag.org/de/home/news/java-aktuell-022022-architektur/detail/ • https://www.digitalfrontiers.de/wp-content/uploads/2022/11/cqrs-und-eventsourcing-in-der-praxis.pdf • https://medium.com/digitalfrontiers/axon-101-handling-client-side-correlation-ids-3f11db66e0a6 Further Reading