Spring Boot Actuator provides several useful features that allow you to monitor and manage your Spring Boot applications. One of the most useful features is the ability to create custom health indicators and metrics. Custom health indicators allow you to define your own health checks and include them in the application’s health endpoint. Custom metrics allow you to gather and expose information about your application to help you identify performance issues.

Creating Custom Health Indicators with Spring Boot Actuator

Creating custom health indicators is straightforward. All you need to do is create a bean that implements the HealthIndicator interface. This interface has only one method, health(), which returns a Health object. The Health object has a status and an optional message. To create a custom health indicator, you just need to define the logic that determines the status of the application and return a Health object that reflects this status.

Once you have created your custom health indicator, you can add it to the application’s health endpoint by setting the management.endpoint.health.group..show-details configuration property to true. The parameter is the name of the group that you want to add your custom health indicator to. If the group doesn’t exist, Spring Boot Actuator will create it automatically.

Advanced Metrics Monitoring in Spring Boot Actuator

Spring Boot Actuator provides a wide range of built-in metrics that you can use to monitor your application’s performance. These metrics include JVM metrics, HTTP request metrics, and more. However, sometimes you need to monitor custom metrics that are specific to your application. To do this, you can use the Micrometer library, which is integrated with Spring Boot Actuator.

To create custom metrics with Micrometer, you need to create a MeterRegistry bean and use it to create a counter or gauge. A counter is a metric that increases every time an event occurs, while a gauge is a metric that reflects the current state of a value. Once you have created your custom metrics, you can expose them via the /actuator/metrics endpoint. You can also use the @Timed annotation to time the execution of a method and expose the results as a metric.

Creating custom health indicators and metrics with Spring Boot Actuator is a powerful way to monitor the health and performance of your application. By creating custom health indicators, you can define your own health checks and include them in the application’s health endpoint. By creating custom metrics, you can gather and expose information about your application to help you identify performance issues. Spring Boot Actuator makes it easy to create and expose these custom health indicators and metrics, so you can focus on building great applications.