Distributed tracing requires instrumentation / app modification (for header forwarding if nothing else), but metrics don't. E.g. Linkerd gives you service "gol

Distributed tracing requires instrumentation / app modification (for header forwarding if nothing else), but metrics don't. E.g. Linkerd gives you service "golden metrics" (success rate, latency distribution, request volumes) without any app changes. It can draw the service topology too, since it's observing everything in realtime. https://linkerd.io/2/features/telemetry/ https://linkerd.io/2/features/telemetry/