Microservices: Azure Cosmos DB to rule them all!

A presentation about Azure Cosmos DB and how to build Microservices with this service and CQRS/ES patterns.

Talk made during the Global Azure Bootcamp 2019 in Rennes.

Video (French) - 1h22 to 2h10 : https://www.youtube.com/watch?v=PLi-XmvtPVs

1. Microservices: Azure Cosmos DB to rule them all! Sylvain Pontoreau
2. global.azurebootcamp.net 2 Thanks to our local sponsor William BORDES Yoann GUILLO
3. global.azurebootcamp.net 3 Thanks to our international sponsor
4. 4 http://sylvain.pontoreau.com Meet the Team Microsoft Engineer Paris TypeScript co-organizer Sylvain PONTOREAU Azure App Engineer @spontoreau https://www.linkedin.com/in/spontoreau
5. Azure Cosmos DB
6. What is Azure Cosmos DB • Cloud Database: https://azure.microsoft.com/en-us/services/cosmos-db/ • Released in may 2017 • Based on Document DB • Multi-model • Globally distributed • High availability • Mathematically viable: https://azure.microsoft.com/en-us/blog/azure-cosmos-db-pushing-the-frontier-of-globally-distributed-databases/ • JavaScript engine embedded
7. They are using Azure Cosmos DB
8. https://azure.microsoft.com/en-us/blog/how-halo-5-guardians-implemented-social-gameplay-using-azure-documentdb/ Halo & Azure Cosmos DB
9. Models
10. • Geo-redundancy Globally distributed
11. Strong Bounded staleness Session Consistent Prefix Eventual Consistency
12. Change Feed Change Feed Event Stream Data
13. APIs
14. Azure Cosmos DB Account Databases Collections Documents Documents in Azure Cosmos DB
15. Azure Cosmos DB SQL Api
16. SDKs
17. • Open source https://github.com/Azure/azure-cosmos-js • Written in TypeScript • NPM Package • Documentation https://docs.microsoft.com/en-us/javascript/api/@azure/cosmos $ npm install @azure/cosmos Node.js SDK
18. const { database} = await client .databases .create({ id: databaseId }); const { container } = await database .container .create({ id: containerId }); const client = new CosmosClient({ endpoint: myEndpoint, auth: { masterKey: myKey } }); CosmosClient, Database & Container
19. const querySpec: SqlQuerySpec = { query: "SELECT root.firstName root.lastName FROM root WHERE root.email = @email", parameters: [{ name: "@email", value: "sypontor@microsoft.com" }] }; const { result } = await container .items .query(querySpec) .toArray(); const item = await container .item(id); const { body: readDoc } = item.read(); Querying
20. const person = { firstName: "Sylvain", lastName: "PONTOREAU", email: "sypontor@microsoft.com" }; const { body } = await container .items .create(person); if(body !== undefined) { console.log(body.id); } const item = await container .item(body.id); const { body: readDoc } = item.read(); readDoc.email = "sylvain@microsoft.com"; await item.replace(readDoc); await item.delete(); Persistence
21. CQRS & Event Sourcing
22. Data Driven Development Domain Driven Design Domain Driven Development != Data structure MCD CRUD Behavior Bounded Context Event
23. Bounded context Independent Autonomous Loosely coupled
24. Query Just a read operation Command Data validation Business logic Persistence CQRS
25. CQRS GetOrderById Query UpdateProduct Command GetProducts Query DeleteOrder Command … … Dispatcher Dispatcher QueryHandler CommandHandler Validation Plugin Monitoring Plugin Telemetry Plugin … Eventual consistency
26. Consistency • All system nodes needs to manipulate exactly the same data at the same time. Availability Partition tolerance • Requests must succeed. • Node failure must not create a complete system failure. A distributed system can only guarantee 2 constrains at the same time, not 3 Eventual consistency?
27. https://martinfowler.com/eaaDev/EventSourcing.html Event Sourcing
28. CQRS & Event Sourcing GetOrderById Query UpdateProduct Command GetProducts Query DeleteOrder Command … … Dispatcher Dispatcher QueryHandler CommandHandler Projection Projection Aggregate State Events
29. Cosmos DB as an Event Store Read Enpoint Write Enpoint Event Store Projector Read DB publish trigger persist query
30. Demo
31. Resources https://docs.microsoft.com/en-us/azure/cosmos-db/introduction https://docs.microsoft.com/en-us/azure/cosmos-db/create-sql-api-nodejs https://docs.microsoft.com/en-us/azure/cosmos-db/change-feed https://medium.com/@thomasweiss_io/planet-scale-event-sourcing-with-azure- cosmos-db-48a557757c8d https://www.youtube.com/watch?v=5YNJpGwj_Zs https://docs.microsoft.com/en-US/azure/architecture/patterns/cqrs https://docs.microsoft.com/en-us/azure/architecture/patterns/event-sourcing https://docs.microsoft.com/en- us/dotnet/standard/microservices-architecture/microservice-ddd-cqrs-patterns/ https://docs.nestjs.com/recipes/cqrs https://gitpitch.com/jrouaix/cqrs-es-presentation/master#/ https://www.youtube.com/watch?v=qBLtZN3p3FU https://www.youtube.com/watch?v=LDW0QWie21s
32. Questions?
33. 33 Merci d’être venus A bientôt !