Spring Boot - Actuator

Spring Boot Actuator includes a number of additional features to help you monitor and manage your application when it’s pushed to production. You can choose to manage and monitor your application using HTTP endpoints, with JMX or even by remote shell (SSH or Telnet). Auditing, health and metrics gathering can be automatically applied to your application. The user guide covers the features in more detail.

Enabling the Actuator

The simplest way to enable the features is to add a dependency to the spring-boot-starter-actuator ‘Starter’. To add the actuator to a Maven based project, add the following ‘Starter’ dependency:

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

For Gradle, use the declaration:

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

Features

• Endpoints Actuator endpoints allow you to monitor and interact with your application. Spring Boot includes a number of built-in endpoints and you can also add your own. For example the health endpoint provides basic application health information. Run up a basic application and look at /health (and see /mappings for a list of other HTTP endpoints).

• Metrics Spring Boot Actuator includes a metrics service with “gauge” and “counter” support. A “gauge” records a single value; and a “counter” records a delta (an increment or decrement). Metrics for all HTTP requests are automatically recorded, so if you hit the metrics endpoint should see a sensible response.

• Audit Spring Boot Actuator has a flexible audit framework that will publish events to an AuditEventRepository. Once Spring Security is in play it automatically publishes authentication events by default. This can be very useful for reporting, and also to implement a lock-out policy based on authentication failures.

• Process Monitoring In Spring Boot Actuator you can find ApplicationPidFileWriter which creates a file containing the application PID (by default in the application directory with a file name of application.pid).