Tracking span durations in Prometheus

[paulkre]

I would like to export the durations of tracing spans as metrics to Prometheus. Is this possible?

[cijothomas]

Yes, by writing a custom SpanProcessor, and reporting the span duration as histogram.record(span.duraion, attributes_from_span).
(Not built-in support, so the custom thing above is the best bet.)

[paulkre]

Would be nice to have something like this built into opentelemetry_sdk