Logging, Metrics, and Distributed Tracing
Logs explain events; metrics explain trends; traces explain request flow across services.
logger.info("Order completed: orderId={}, durationMs={}",
orderId, durationMs);
Useful production metrics include request rate, error rate, latency, saturation, queue depth, database pool usage, and JVM/GC health. Observability data itself should be treated as sensitive.
Key Takeaways
- Use logs, metrics, and traces together.
- Correlation IDs make distributed debugging easier.
- Observability data must be treated as sensitive production data.