EVENT SOURCING — THE PRIVILEGED MODEL FOR INDIRECTION — PART 3

• You can read the part 1 here.
• You can read the part 2 here.

In the last parts it was presented an evolutionary path towards an event driven architecture to support multiple read models. We ended with an architecture with a relational database that supports write operations where the business invariants are ensured, an event queue, a broker to dispatch messages, and an Integrator to update changes to read-only databases (Image 1). In this part 3 It will be presented an Event Sourcing alternative and be discussed some nuances in the adoption of such solution.

Image 1 — Final Architecture from part 2.

Event Sourcing is a radically different way to persistence. An object state is persisted by storing the sequences of state changing events.

The realization of an Event Sourcing model is very simple, just use the state change events as the persistence model.

Abandoning the relational representation of the state allows to simplify the write model because we only need to maintain the event model instead of two different models. Using events as the state…