Metrics, Logs and Traces

The three signals

Spring Boot instruments HTTP requests, database pools and JVM internals with Micrometer; export metrics to Prometheus, Datadog or other backends by adding a registry dependency. Tracing (Micrometer Tracing with OpenTelemetry) follows requests across services and puts trace ids into logs. Use structured (JSON) logging, which Spring Boot supports natively, so logs, metrics and traces can be correlated.

Enabling Prometheus metrics (sketch)

Not part of the built demo; check the Spring documentation for your version.

# pom.xml: add io.micrometer:micrometer-registry-prometheus
management.endpoints.web.exposure.include=health,info,prometheus
management.metrics.tags.application=${spring.application.name}
logging.structured.format.console=ecs     # structured JSON logs

Tag metrics with the application name

Common tags (application, environment, region) make dashboards across many services usable.

Quick check: Which library does Spring Boot use for metrics instrumentation?

• JUnit
• Micrometer
• Hibernate
• Thymeleaf