Distributed Traces
What path did this particular operation take? A sensor of execution flow across service boundaries — the span tree is itself a signal.
A trace shows you the actual path a request took through your system: which services were called, in what order, how long each took. Where observability events give you per-execution facts, traces give you the shape of execution.
Sensor properties
| Property | Value |
|---|---|
| Oracle strength | Medium — shows what happened, not whether it was correct |
| Independence | High — production reality |
| Scope | System-level |
| Feedback latency | Seconds |
| Actionability | Exploratory — you trace to find the signal |
| Type | Retrospective |
What it cannot detect
Traces show execution paths but not correctness. A trace that completes successfully may still violate a business invariant. Pair traces with invariant checking for correctness signal.