What is Spring Boot Actuator?
Options
- A UI framework that is used to build web pages
- A module with health, metrics and info endpoints (Correct option)
- A code generator that creates the controllers
- A database driver for the relational databases
Answer
A module exposing operational endpoints such as /actuator/health, metrics and info, used for monitoring and Kubernetes probes
Why
Add spring-boot-starter-actuator and you get endpoints to see how the app is doing: /actuator/health (is it up? is the database reachable?), /actuator/metrics, /actuator/info.
Orchestrators like Kubernetes call the health endpoint for liveness and readiness probes. Metrics integrate with Prometheus/Micrometer.
Expose only what you need and protect the rest: some endpoints reveal sensitive details.
Remember
Actuator = health and metrics endpoints for operations.