[hinkley]

That was two years ago (we tried spans before metrics), so it’s fuzzy. I believe the collector sidecar was fine with it but the backend was not, which complicated debugging. There’s not a clear feedback path in OpenTelemetry that we could find. I completely forgot to mention the tendency toward silent failures. That’s a cardinal sin for telemetry. I would take it out back and shoot it for that fact alone.

The other problem I noticed looking at the wire protocol was that the data for the parent trace doesn’t seem to get sent until the trace closes. That seems like a bookkeeping nightmare to me. There should be a start of trace packet and an update at the end. I shouldn’t have finished spans showing up before the parent trace has been registered. And that’s what it looked like in the dumps my OPs people sent me to debug.