Is Kafka event sourcing?
TL;DR: Kafka is not an event store; rather, it is an enabler for building event stores. For the most trivial of use cases, Kafka’s support for unbounded retention, combined with per-entity record keying, tombstones and topic compaction may be used to build a very rudimentary event store.
What is Event Store in Event Sourcing?
Entities as event streams So, Event Sourcing is the persistence mechanism where each state transition for a given entity is represented as a domain event that gets persisted to an event database (event store). When the entity state mutates, a new event is produced and saved.
Is it possible to use CQRS without Event Sourcing?
While together they work really well, CQRS without Event Sourcing is still a viable architectural approach offering quite some benefits. In general, I agree on that. Basically, CQRS is all abo u t separating state changes from queries.
How are event streams used in CQRS systems?
Most CQRS implementations utilize event streams as a trigger for data projection. This is an elegant approach, as events naturally describe application state changes. And most (distributed) systems somehow already process them. Processing an application state change usually involves the following steps:
Can you build a persistence based on CQRS?
Thus, if you want to build a CQRS-based architecture, it is beneficial to know the alternatives to a persistence based on Event Sourcing. Some blog articles and posts on Stackoverflow refer to CQRS and Event Sourcing as “orthogonal concepts”, which can be applied independently of each other.
Which is an example of a CQRS handler?
Basically, CQRS is all abo u t separating state changes from queries. For example, Command Handlers could trigger domain logic operating on a traditional relational database. The read-side could use a NoSQL database, and the events which are emitted by command handlers on the write-side can be used to update the persistent state on the read-side.