Allow overriding propagation of tracing headers

[giovanniberti]

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Azure API Management without Diagnostic Logs enabled injects traceparent headers with the sampling flag set to 0.
This causes the agent to not emit traces on instrumented services, and there's no easy way to override this behaviour from APIM without enabliing Diagnostic Logs.

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I would like a configuration option to allow the agent to ignore incoming tracing headers, like this option on the Elastic APM.

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An alternative would be to use AlwaysOn sampler, but I'd rather have something more fine-grained if possible :)

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[mateuszrzeszutek]

Related links: #8038, open-telemetry/opentelemetry-specification#1633

[trask]

hi @giovanniberti! you could use a java agent extension to provide your own sampler which is not "parent based" (i.e. ignores the traceparent sampling flag)

[github-actions]

This has been automatically marked as stale because it has been marked as needing author feedback and has not had any activity for 7 days. It will be closed automatically if there is no response from the author within 7 additional days from this comment.