How to Enable Spring Boot Actuator to Your Application

Spring Boot Actuator is a powerful tool that comes bundled with Spring Boot applications. It gives you production-ready features, like application health check monitoring, incoming traffic, database running state, and gathering metrics (usage of core processors, heap memory, threads, loaded/unloaded classes, and thread pooling).

In this blog, we will learn in detail about how to enable the Spring Boot actuator to your application.

Steps to Enable Spring Boot Actuator

Enabling Spring Boot Actuator is a straightforward process and can be done in several ways, depending on your preference and project setup:

Step #1

Let’s first create a Spring Boot project using start.spring.io

A. ENABLING SPRING ACTUATOR

You can add dependency manually in your existing project like this:

Maven dependency

We can enable the actuator by injecting the pom.xml file.

<dependency>

<groupid>org.springframework.boot<groupid>

<artifactid>spring-boot-starter-actuator</artifactid>

</dependency> 

Gradle Dependency

Or, we can do it by injecting the gradle file.

compile group: ‘org.springframework.boot’, name:’spring-boot-starter-actuator’

Run the following command in your project’s terminal root directory.

mvn spring-boot:run

NOTE: By default, It runs on port 8080. We can override settings by configuring the application.properties file. 

management.server.port=8080

B.  MONITORING APPLICATION THROUGH ACTUATOR SO-CALLED ENDPOINTS

Actuator, by default, generates so-called endpoints that can be exposed over HTTP or HTTPs or JMX to let your application monitor.

Most applications reveal endpoints through HTTP, where the ID of the endpoint close by a prefix of /actuator is intended for a URL. For example, Normally, the health endpoint is intended for/actuator/health.

By default, Only the /health endpoint is accessible via HTTP. That’s why the /actuator page lists only the health endpoint.  

Here, we’ll shortly figure out how to expose other actuator’s endpoints.

 

Enabling Common Actuator Endpoints

/health Endpoint 

This endpoint shows the status of the application as follows:

{

    “status”: “UP“

}

The status will be UP as long as the application is in a healthy state. It will start showing DOWN as it gets any database connectivity issues or lack of disk space. 

Also, check the health of your application by combining several health indicators. 

Spring Boot actuator comes with different pre-defined health indicators. i.e. DataSourceHealthIndicator, RedisHealthIndicator, DiskSpaceHealthIndicator etc. It uses these health indicators as a part of the health check-up process.

We can enable/disable particular health indicators by using the following property.

management.health.redis.enabled = false

NOTE: By default, all health indicators are enabled and take part in the health check-up process. 

Displaying Detailed Health Information 

Default Health Endpoint shows only UP or DOWN status. In order to get the complete status of every health indicator that took part in the health check-up process. 

management.endpoint.health.show-details =true

Configure Custom Path

By default, /actuator is the endpoint to trace health indicators. We can also customize paths by using the following property in the application.properties file.

management.endpoints.web.base-path=details

/metrics Endpoint

This endpoint lists all the metrics that can be tracked. For example, system.cpu.usage, jvm.memory.max, etc.

In order to get the details of a specific metric, we need to pass only the metric name with the following URL. 

http://localhost:8080/actuator/metrics/{metric_name}

For example, use the following URL to get the details of system.cpu.usage metric. 

http://localhost:8080/actuator/metrics/system.cpu.usage

Below is the output of the above endpoint.

Sprint Boot Actuator Endpoints Examples

There are a few different endpoints that you can also check, for example:

Endpoint ID	Description
catches	It shows accessible caches
loggers	It provides a list of all the configured log levels for each of your application’s configured loggers.
mappings	Lists down all the @RequestMapping paths.
sessions	Allows deletion and reterival of user sessions from Spring Session-backend session store.
beans	It lists down all the Spring beans in your application.
env	To see the list of environment variables used in our application.

Conclusion

Enabling Spring Boot Actuator in your application can provide valuable insights into its performance and health. By following the steps outlined above, you can easily enable the actuator and access powerful features like monitoring endpoints, detailed health information, and tracking metrics.