Spring Boot Actuator: Monitoring Your Application with Essential Endpoints

Spring Boot Actuator provides powerful production-ready features for monitoring and managing applications, offering an impressive set of endpoints to inspect application state, health, configuration, and more. This article will cover these essential endpoints, giving you practical examples and insights into their usefulness in real-world applications.

Benefits of Using Spring Boot Actuator

Actuator is popular among developers for its convenience in managing applications at runtime. Its primary benefits include:

• Simplified monitoring with built-in endpoints.
• Real-time health checks for system status.
• Detailed visibility into application metrics.
• Easy integration with external monitoring systems.

Setting Up Actuator in Your Spring Boot Application

To enable Actuator, add the following dependency to your pom.xml file:

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

After including the dependency, Actuator’s endpoints are automatically available at /actuator However, you can customize this path if necessary.

Overview of Actuator Endpoints

The actuator provides multiple endpoints, each tailored to a specific purpose. They allow you to monitor and control different aspects of your application’s state, environment, configurations, and performance.

Actuator Endpoints Explained

Let’s dive into the most commonly used Actuator endpoints and their purposes, along with examples to show how they work.

The /info Endpoint

The /info endpoint provides basic information about your application, which you can customize with metadata like version numbers or environment-specific details.

Example:

To add custom information, add properties to your application.yml:

info:
 app:
  name: "My Application"
    version: "1.0.0"

When you access /actuator/info, the response might look like this:

{
 "app": {
 "name": "My Application",
 "version": "1.0.0"
}
}

The /health Endpoint

The /health endpoint checks the status of the application and its dependencies, making it ideal for health checks in deployment environments.

Example:

Accessing /actuator/health typically returns:

{
"status": "UP",
"components": {
"diskSpace": {
"status": "UP",
"details": {
"total": 499963174912,
"free": 261674819584,
"threshold": 10485760
}
}
}
}

The /beans Endpoint

The /beans endpoint lists all Spring beans in the application context, useful for understanding bean dependencies and configurations.

Example:

Accessing /actuator/beans will return a large JSON structure detailing each bean, its class type, and its dependencies.

The /conditions Endpoint

The /conditions endpoint provides information on conditions that determine which beans and configurations were included in the application context.

Example:

A response from /actuator/conditions can help in troubleshooting conditional configurations and autowiring issues in complex Spring setups.

The /mappings Endpoint

The /mappings endpoint lists all the request mappings in the application, useful for understanding how routes are defined and handled.

Example:

A request to /actuator/mappings returns JSON data showing each URL path and the associated controller or handler method.

The /configprops Endpoint

The /configprops endpoint displays all configuration properties, showing the properties that Spring has configured and their values.

Example:

Using /actuator/configprops helps ensure that configuration properties are correctly set up and assists in troubleshooting configuration issue

The /metrics Endpoint

The /metrics endpoint is one of the most powerful, providing insights into various metrics like memory, CPU usage, and application-specific data.

Specific metrics can be queried by appending metric names, such as /actuator/metrics/http.server.requests

The /env Endpoint

The /env endpoint provides access to environment properties, including system properties and configuration properties. This endpoint is beneficial for debugging configuration issues.

Example:

Access /actuator/env to view all environment variables:

The /threaddump Endpoint

The /threaddump endpoint generates a thread dump for the application, which is invaluable for diagnosing performance bottlenecks or deadlocks.

Example:

Accessing /actuator/threaddump provides details on active threads and their states.

The /loggers Endpoint

The /loggers endpoint provides control over the logging levels for various parts of the application, allowing you to modify logging behavior dynamically.

You can also change the log level of specific loggers by sending a POST request /actuator/loggers/{loggerName}

Security and Customization of Actuator Endpoints

By default, sensitive endpoints are restricted. To secure endpoints, use Spring Security or customize which endpoints are available in the application.yml:

management:
 endpoint:
  health:
   show-details: "always"
endpoints:
 web:
  exposure:
    include: "*"