In Chapter 4, Creating Reactive Microservices, we learned how we can create non-blocking reactive microservices. However, if our microservices need to query data using blocking operations, we will lose the benefits of the reactive programming. Spring Framework 5 and Spring Data provide reactive capabilities for most modern databases.
We reviewed the main concepts of reactive programming in Chapter 1, Understanding Microservices, in the Reactive Microservices section. You can review this section to get more insight into this new reactive programming model.
In this chapter, we will learn how to use Spring Data to perform reactive operations against our database. But first, we will learn how to use and configure MongoDB in our applications, the NoSQL database chosen for this chapter. Then, we will see how we can easily connect our previously created RESTful APIs...