Java EE 8 Design Patterns and Best Practices

The event sourcing pattern

In a typical approach, an application changes the state of data when a user works with it. However, this approach can often slow down performance and responsiveness and can also generate other concurrent updates. Unless we use an additional mechanism, we don't have a mechanism to audit and log operations or generate history.

Event sourcing is a pattern that maintains the current data state and saves data update events in an event repository. This repository works as an append-only store, and when the data is accessed by a consumer, it receives the event and applies the update on the domain. Using this pattern promotes performance by decoupling the event logic and scalability and by auditing all actions applied to ...