A Stateful Aggregate is a consistency boundary and its Event Sourced entity can have strong consistency guarantees. Many other parts of a Microservice can’t be updated atomically together with the entities, such as Projections that update different representations from the events of the entities. Those updates are eventually consistent with the origin change. Eventual consistency means that the updates may take some time to propagate but eventually they will, also in the case of failures that are eventually resolved. Updates between different Microservices are typically also eventually consistent.
|Accept Uncertainty Tailor Consistency is one of the Reactive Principles.|