Hands-On Reactive Programming in Spring 5

The SAGA pattern

One of the most popular patterns for distributed transactions, especially in a microservice world, is called the SAGA pattern. This was introduced in 1987 to manage long-lived transactions in databases.

A saga consists of a few small transactions, each of which is local to its microservice. Here, an external request initiates the saga, and in turn, it starts the first small transaction, which upon successful completion triggers the second transaction, and so on. If a transaction fails to succeed in the middle, it triggers a compensation action for the previous transactions. The are two main ways to implement the pattern—events-based choreography and orchestration via a coordinator service.