In this post, we will look at how we can use the spring boot actuator to add some metrics related endpoints in Spring Boot based microservice or application. Spring boot helps to monitor your production-ready application by offering a number of metrics related endpoints.

What do you need:

• Java 8
• Spring Boot
• IntelliJ
• Gradle

What are Spring boot actuator endpoints?

I will not be showing how to create a Spring boot REST in this article. You can refer my post to create a REST API based on Spring boot here.

As Spring documentation says – “Spring boot actuator let you monitor and interact with your application.” The endpoints that we will be discussing, are built in Spring Boot. Of course, the first question that comes to mind, is how do we activate these endpoints and what different endpoints are available there for what purposes.

How to activate actuator endpoints?

To activate these endpoints in a gradle-based project, we have to add the following dependency

dependencies {
  compile("org.springframework.boot:spring-boot-starter-actuator")
}

If you are using maven, this will be like below:

<dependencies>
  <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-actuator</artifactId>
  </dependency>
</dependencies>

All the actuator endpoints are enabled by default.

• auditevents – Audit events of your application
• info– Displays information about your application – you can customize to show version information.
• health – application’s health status
• metrics – various metrics information of application
• loggers – Displays and modifies configured loggers
• logfile – Shows the contents of the log file
• httptrace – Displays HTTP trace info for the last 100 HTTP request/response
• env – Displays current environment information
• flyway – Shows Flyway database migrations details
• liquidbase – Shows details of liquibase database migrations
• shutdown – Allows to shut down the application gracefully
• mappings– Displays a list of all @RequestMapping paths
• scheduledtasks – Displays the scheduled tasks in the application
• threaddump – Performs a thread dump
• headdump – Returns JVM head dump

Another way these endpoints can be enabled or disabled, is to add properties in application.properties as shown below:

management.endpoint.health.enabled=true

Running the spring boot application with actuator

Once we have added the required spring-boot-starter-actuator dependency, we can build our application. There is still one more change we need to add in our gradle build file to get application version information.

springBoot{
     buildInfo()
}

If you are using maven, this can be added as below:

<plugin>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-maven-plugin</artifactId>
    <executions>
        <execution>
            <goals>
                <goal>build-info</goal>
            </goals>
        </execution>
    </executions>
</plugin>

If you want to add some additional properties, add following properties in application.properties as below:

info.app.name = Reusable-Rest-Module
info.app.version = 0.1.0-SNAPSHOT
management.security.enabled=false

Now once you build the application and run it, this will give us following results:

Conclusion

In this post, we showed how we can use Spring Boot Actuator to get different metrics data for your spring boot based service.