EVENT BASED MICROSERVICES - Event Sourcing In a Microservice Architecture, especially with Database per Microservice, the Microservices need to exchange data. For resilient, highly scalable, and fault-tolerant systems, they should communicate asynchronously by exchanging Events. In such a case, you may want to have Atomic operations, e.g., update the Database and send the message. If you have SQL databases and want to have distributed transactions for a high volume of data, you cannot use the two-phase locking (2PL) as it does not scale. If you use NoSQL Databases and want to have a distributed transaction, you cannot use 2PL as many NoSQL databases do not support two-phase locking. In such scenarios, use Event based Architecture with Event Sourcing. In traditional databases, the Business Entity with the current “state” is directly stored. In Event Sourcing, any state-changing event or other significant events are stored instead of the entities. It means the modifications of a Busines