Tracking Changes with Event Sourcing
In the previous chapter, our MallBots application was updated to use events to communicate the side effects of changes to other parts of a module. These domain events are transient and disappear once the process ends. This chapter will build on the previous chapter’s efforts by recording these events in the database to maintain a history of the modifications made to the aggregate.
In this chapter, we will be updating our domain events to support event sourcing, add an event sourcing package with new types, and create and use Command and Query Responsibility Segregation (CQRS) read models projected from our domain events. Finally, we will learn how to implement aggregate snapshots. Here is a quick rundown of the topics that we will be covering:
- What is event sourcing?
- Adding event sourcing to the monolith
- Using just enough CQRS
- Aggregate event stream lifetimes
By the end of this chapter, you will understand how...
