I Sent Cloudflare AI Gateway OTel Spans to Grafana Tempo. Success Spans Arrived, Error Spans Did Not
I sent OpenTelemetry spans from Cloudflare AI Gateway and a Node.js agent to Grafana Tempo under the same trace ID, then compared a successful response, a client timeout, an invalid model error, and a fallback. The results reveal missing error spans, different duration boundaries across the app, Gateway logs, and OTel spans, and the need for a separate observation point for response quality.