Observability for cloud native systems is commonly described as resting on three primary signal types. A team wants to record the exact ordered path a single user request took as it hopped across several microservices, including how long it spent in each service. Which of the three signals is designed to capture that per-request cross-service journey?
- AMetrics, because they aggregate numeric measurements sampled over time into series that can be graphed and alerted on.
- BLogs, because each service writes a timestamped text record that can be searched after the fact.
- CTraces, because they follow one request end to end and record a span for each service it passes through with per-service timing. Correct
- DEvents, because they publish a discrete notification whenever a service changes state during the request.
Why A is wrong: Metrics are tempting because they do capture latency numbers, but they aggregate values across many requests and cannot reconstruct the ordered path of one specific request through the services.
Why B is wrong: Logs are tempting since each service does emit timestamped records, but without correlation they are discrete events per service and do not by themselves reconstruct one request's ordered cross-service path.
Why C is correct: Distributed traces are exactly the signal for this: they stitch together spans from each service a single request touches, preserving order and per-hop duration.
Why D is wrong: Events sound relevant because they mark state changes, but they are not one of the three core observability signals and do not record a request's full ordered journey with per-service timing.