Use Cases
In a distributed system the service that got slow is rarely the service that broke. The map shows which edge degraded first, and the trace shows how far the wait propagated.
signal api-gateway p95 1.9 s · was 0.9 s, no deploy
The path
payment-svc@1.4.2 is the release that shipped four hours before the symptom. It holds the path together — the map, the trace and the logs are all filtered to it.
api-gateway is the service being paged about, but its own spans are fine. The degraded edge is two hops in: payment-svc to user-db, average up from 12 ms to 210 ms.

Open a slow request and the db span is almost all of it. The query itself is 4 ms; the span is 210 ms. The difference is time spent before the query ever ran.

Lines from that span read pool wait 206 ms, acquired after 3 attempts. Filter by service.version and they start at 1.4.2 — which raised concurrency without raising the pool.

outcome
Pool size raised to match the new concurrency. The p95 edge latency returned to 14 ms without a rollback.
What it does
One endpoint, one key. Traces, logs, metrics and sessions land on the same trace id from the first request.