Distributed tracing.
also: distributed traces · trace context · traceparent · OpenTelemetry · trace ID · trace IDs · trace context propagationFollowing one request across services: a trace is the whole journey, made of timed spans for each step, linked by a propagated trace ID.
the two-minute refresher
- Trace abc-123: gateway 12 ms → auth 5 ms → token validation 2 ms…
- Each service passes the trace context on (headers, message metadata).
- Answers 'where is it slow?' and 'where did it fail?' across services.
- Usually sampled, since tracing every request is costly.