← the index · class 07 · one trace
POST /orders → 201 in 469 ms
trace 39040ca8b55b53c8d833ebb2a4e3d1bb · correlation c-f8b1 · 2026-11-01 13:16:27.320 UTC
The waterfall
Each bar is a span; together they are one trace, because each service passed on the
traceparent it received. A bar covers its children: the gateway's lasts the whole request, but only
part of it is its own work.
Where the time goes
The own time of each span — its duration minus its children's: the boxes of the slide. Added up, they are what the user waited for.
| Service | Operation | Starts at | Span | Own time | Share | Attributes |
|---|---|---|---|---|---|---|
| gateway | POST /orders | 0 ms | 469 ms | 12 ms | 3% | http.status=201 |
| orders | create | 6 ms | 457 ms | 38 ms | 8% | order_id=1841 |
| catalogue | reserve-stock | 16 ms | 9 ms | 9 ms | 2% | items=1 |
| payments | charge | 29 ms | 410 ms | 410 ms | 87% | amount_cent=14970 |
What crossed each hop
Between two services only the headers travel. Propagate, never generate: every service after the gateway
received the same X-Correlation, and a traceparent naming the span that called it.
| Service | X-Correlation received | traceparent received |
|---|---|---|
| gateway | none — it generated c-f8b1 | none — it started the trace |
| orders | c-f8b1 | 00-39040ca8b55b53c8d833ebb2a4e3d1bb-5fb53307d9474ed7-01 |
| catalogue | c-f8b1 | 00-39040ca8b55b53c8d833ebb2a4e3d1bb-ddd5b6e997a8b5dd-01 |
| payments | c-f8b1 | 00-39040ca8b55b53c8d833ebb2a4e3d1bb-ddd5b6e997a8b5dd-01 |
The log lines with correlation c-f8b1
Written by four services into one store, found by one field — the same as
/logs?correlation=c-f8b1. Each line also carries the
trace_id: that is the jump from a log line to its trace. The card number that payments received is not
there: log.Filter dropped it.
{"time":"2026-11-01T13:16:27.345183193Z","level":"INFO","msg":"stock reserved","service":"catalogue","correlation":"c-f8b1","trace_id":"39040ca8b55b53c8d833ebb2a4e3d1bb","lines":1} {"time":"2026-11-01T13:16:27.759183193Z","level":"INFO","msg":"payment charged","service":"payments","correlation":"c-f8b1","trace_id":"39040ca8b55b53c8d833ebb2a4e3d1bb","order_id":1841,"amount_cent":14970,"provider_ms":410} {"time":"2026-11-01T13:16:27.783183193Z","level":"INFO","msg":"order created","service":"orders","correlation":"c-f8b1","trace_id":"39040ca8b55b53c8d833ebb2a4e3d1bb","order_id":1841,"items":3,"total_cent":14970,"duration_ms":457} {"time":"2026-11-01T13:16:27.789183193Z","level":"INFO","msg":"request handled","service":"gateway","correlation":"c-f8b1","trace_id":"39040ca8b55b53c8d833ebb2a4e3d1bb","method":"POST","route":"/orders","status":201,"duration_ms":469}