Spring Boot Actuator is a sub-project of Spring Boot that provides a set of production-ready features to help you monitor and manage your Spring Boot application. Its primary purpose is to offer out-of-the-box tools for monitoring, measuring, and managing Spring Boot applications in production environments.

Key Features and Endpoints Provided by Spring Boot Actuator

Key Features:

A. Health Checks: Provides insights into the application's health status. This feature can be leveraged by monitoring systems to detect if the application is running smoothly.

B. Metrics: Collects and exposes various metrics about the application, such as memory usage, request rates, thread pools, garbage collection stats, etc.
C. Auditing: Tracks and logs requests made to the application, helping in auditing and debugging.

D. Environment Information: Retrieves details about the application's environment, including properties, configuration, and dependencies.

E. Thread Dump: Generates a thread dump of the application's JVM, useful for diagnosing performance issues and deadlocks.

Heap Dump: Generates a heap dump of the application's JVM, helpful for memory analysis and troubleshooting memory leaks.
Key Endpoints:

/actuator/health: Provides information about the application's health.
/actuator/info: Exposes arbitrary application info.
/actuator/metrics: Retrieves various metrics about the application.
/actuator/env: Displays the current application environment.
/actuator/loggers: Allows for configuring application logging levels.
/actuator/auditevents: Provides access to audit events.
/actuator/httptrace: Provides details of HTTP requests and responses.
/actuator/threaddump: Generates a thread dump of the JVM.
/actuator/heapdump: Generates a heap dump of the JVM.

1. Enabling and Customizing Actuator Endpoints in a Spring Boot Application

Enabling Actuator:
To enable Actuator endpoints in a Spring Boot application, you typically just need to include the Actuator starter dependency in your pom.xml or build.gradle file:

xml
Copy code

org.springframework.boot
spring-boot-starter-actuator

or

groovy
Copy code
implementation 'org.springframework.boot:spring-boot-starter-actuator'
Customizing Endpoints:
You can customize Actuator endpoints by modifying properties in the application.properties or application.yml file. For example:

properties
Copy code

Customize the health endpoint

management.endpoint.health.show-details=always

Customize the metrics endpoint

management.endpoint.metrics.enabled=true
management.metrics.export.influx.enabled=true
Exposing Additional Endpoints:
You can expose additional Actuator endpoints by configuring the management.endpoints.web.exposure.include property:

properties
Copy code
management.endpoints.web.exposure.include=health,info,metrics
This will expose only the specified endpoints.

Summary:

Spring Boot Actuator is a project aimed at providing production-ready features for monitoring and managing Spring Boot applications.
Key features include health checks, metrics collection, auditing, environment information retrieval, and thread and heap dump generation.
Key endpoints such as /actuator/health, /actuator/info, /actuator/metrics, etc., provide access to various monitoring and management functionalities.
Enabling Actuator is as simple as adding the Actuator starter dependency, while customizing endpoints involves configuring properties in the application configuration file.
Actuator is a powerful tool for ensuring the reliability and stability of Spring Boot applications in production environments