What is Spring Boot Actuator?

Spring Boot Actuator provides production-ready management and monitoring endpoints for Spring Boot applications. Add: spring-boot-starter-actuator. Built-in endpoints (at /actuator/{endpoint}): /actuator/health — application health status (UP/DOWN) and component health; /actuator/info — application info (from application.properties or git info); /actuator/metrics — detailed metrics (JVM memory, CPU, HTTP requests, custom metrics); /actuator/env — environment properties and configuration; /actuator/beans — all beans in the application context; /actuator/mappings — all request mappings; /actuator/loggers — view and modify log levels at runtime; /actuator/threaddump — thread dump; /actuator/heapdump — heap dump; /actuator/httptrace — recent HTTP requests; /actuator/shutdown — graceful shutdown (disabled by default). Configuration: management.endpoints.web.exposure.include=health,info,metrics,loggers management.endpoint.health.show-details=always management.server.port=8081 # Separate port for actuator. Security: restrict actuator endpoints — require authentication. Use Spring Security to protect /actuator/** with ACTUATOR role. Expose only needed endpoints. Custom health indicator: implement HealthIndicator interface to add custom health checks. Metrics integration: Actuator integrates with Micrometer — expose metrics to Prometheus/Grafana/Datadog.