3.8. Microservice Event¶

3.8.1. Event-driven Architecture¶

Use an event-driven, eventually consistent approach. Each service
publishes an event whenever it update it's data. Other service subscribe to events. When an event is received, a service updates it's data.

3.8.2. Event Sourcing¶

Reliably publish events whenever state changes by using Event
Sourcing. Event Sourcing persists each business entity as a sequence of events, which are replayed to reconstruct the current state.

Event sourcing:

../../_images/microservices-event-sourcing.png

3.8.3. Application Events¶

Reliably publish events whenever state changes by having the application insert events into an EVENTS table as part of the local transaction. A separate process polls the EVENTS table and publishes the events to a message broker.