Listed next are some of the Event Sourcing laws which need to be maintained while implementing ES on any system (that is, application design):
- Idempotency: An ideal event-sourced business logic must be idempotent. This means that when you execute a business logic against an input stream of data, the resultant state of the application will always remain the same. Yes, that's true, it will remain the same irrespective of the number of times you execute the business logic.
- Isolation: Event Sourcing must not depend on the external event streams. This is one of the most important tenets of Event Sourcing. Generally, business logic is rarely ever executed in a vacuum. Applications usually interact with external entities ...
