Observability: logs, metrics, traces

Three pillars, one story

A production service you can't see into is a service you can't maintain. Observability rests on three pillars: logs for narrative per request, metrics for aggregate health and SLOs, and traces for the cross-service causality of a single request. Spring Boot Actuator, Micrometer, and an OpenTelemetry exporter give you all three in a few lines.

• Structured logs with correlation IDs — so you can follow one request across layers.
• Metrics with clear names and labels — latency histograms, error rates, queue depth.
• Traces that stitch spans across services — invaluable for distributed systems.