Using Micrometer to trace your Spring Data JPA application

In a previous article, we saw the goodness of stirring a little Micrometer into our Spring Boot 3 application to trace what our application did. We saw how to activate the Micrometer bindings buried deep in Spring Boot for web calls. And we piped all those good metrics into Zipkin, the open source distributed tracing system thanks to Docker.

But that wasn’t very “realistic” cuz we didn’t have a “real” database underneath it.

Everyone know that real apps have data, right? So why not put something together!

To kick things off, after fashioning an app using start.spring.io, Spring Data JPA, and H2, we need a domain object. Let’s craft something like this:

@Entity
public class Employee {

 @Id
 @GeneratedValue private Long id;
 private String name;
 private String role;

//...constructors/getters/setters ommitted for brevity...
}

A basic domain object that lets us model the Employees in our payroll system. This entity class is properly annotated with @jakarta.persistence.Entity (remember Spring Boot 3 is on Jakarta EE 10!). It also has the id field marked up as the primary key using @jakarta.persistence.Id. We will also let the JPA persistence provider handle primary key generation by using @jakarta.persistence.GeneratedValue.

Even though Spring Data provides some cool features, we STILL have to model our entity classes properly for things to come together!