OpenTelemetry::SDK || Requests with x_request_id

[AlexeyRyabchikov]

I noticed that when you enable sampling, in order to send a request and get a metric for sure, you need to write your own CustomSampler class.

I suggest adding the ability to transmit the x_request_id, for example, in HTTP requests, to ensure that the trace is sent when sampling is enabled.

[plantfansam]

Hi Alexey! The sampling decision of a parent span from an inbound web request are decoded using https://opentelemetry.io/docs/specs/otel/context/api-propagators/, the standard of which is by default traceparent(see code and w3c). If you would like opentelemetry-ruby to interpret and/or forward along x_request_id (I think this is what you're after), you'd need to write a custom propagator.