Spring Boot actuators for microservices instrumentation

The previous sections explored most of the Spring Boot features required for developing a microservices. In this section, we will explore some of the production-ready operational aspects of Spring Boot.

Spring Boot actuators provide an excellent out-of-the-box mechanism for monitoring and managing Spring Boot microservices in production.

The full source code of this example is available as the chapter3.bootactuator project in the code files of this book under the following Git repository: https://github.com/rajeshrv/Spring5Microservice

Create another Spring starter project, and name it as chapter3.bootactuator.application; this time, select the Web, HAL browser, hateoas, and Actuator dependencies. Similar to chapter3.bootrest , add a GreeterController endpoint with the greet method. Add management.security.enabled=false to the application.properties file to grant access to all endpoints.

Do the following to execute the application:

Start the application as Spring Boot App.
Point the browser to localhost:8080/application. This will open the HAL browser. Review the Links section.

A number of links are available under the Links section. These are automatically exposed by the Spring Boot actuator:

Some of the important links are listed as follows:

dump: Performs a thread dump and displays the result
mappings: Displays a list of all the http request mappings
info: Displays information about the application
health: Displays the health condition of the application
autoconfig: Displays the auto configuration report
metrics: Shows different metrics collected from the application

From the browser, individual endpoints are accessible using /application/<endpoint_name>. For example, to access the /health endpoint, point the browser to localhost:8080/application/health.