Implement Transactions across Microservices Using the Saga Pattern

We have just looked at database development and what we need to consider when building an application developed using a microservices architecture. We discussed the pros and cons of creating individual databases per microservice. It does allow each microservice to have more autonomy, allowing us to choose the best technology needed for the service. While it is preferred and a recommended technique, it does have significant drawbacks when it comes to ensuring data consistency across the data stores.

Typically, we ensure consistency through transactions. Transactions, as discussed earlier in this book, ensure that all data is committed or none. That way, we can ensure that an operation will not partially write data and that what we see truly reflects the state of the data being tracked.

It is difficult to enforce transactions across microservices with different databases, but that is when we employ the saga pattern...