Saga - Distributed Transactions

In microservices architecture, it is recommended that each service has its own database. Some business transactions, however, span multiple service so you need a mechanism to ensure data consistency across services. How to maintain data consistency across services? In microservices architecture, we don’t havethe luxury of XA transaction.

The answer is Saga which is a sequence of local transactions. Each local transaction updates the database and publishes a message or event to trigger the next local transaction in the saga. If a local transaction fails because it violates a business rule then the saga executes a series of compensating transactions that undo the changes that were made by the preceding local transactions.