Take trace_state into account when calculating span metrics

[joe-elliott]

When using w3c tracing context propagation OTel will propagate "trace state" here:

https://github.com/open-telemetry/opentelemetry-proto/blob/c4dfbc51f3cd4089778555a2ac5d9bc093ed2956/opentelemetry/proto/trace/v1/trace.proto#L100

The data in this string can contain information about how the trace was sampled:

https://opentelemetry.io/docs/specs/otel/trace/tracestate-probability-sampling/

If this information is present it can be used to reverse the impact of sampling. Add a configuration option that, when set to true, checks for trace state and uses it to inflate metrics to "undo" sampling.

[joe-elliott]

Let's hold on this. I've heard that the linked tracestate documentation is up for debate now in OTEL. After they've settled on how to communicate this information we can revisit.

[github-actions]

This issue has been automatically marked as stale because it has not had any activity in the past 60 days.
The next time this stale check runs, the stale label will be removed if there is new activity. The issue will be closed after 15 days if there is no new activity.
Please apply keepalive label to exempt this Issue.

[adirmatzkin]

Should we add a keep-alive label? 😊 @joe-elliott

[joe-elliott]

It looks like it has a keepalive label? Not sure what happened there.

[gavin-jeong]

Any updates? want to take root span name info with this