Passing standard tracing headers from the initial request

[mityayak]

Is it possible to automatically pass standard tracing headers from the initial request into subsequent calls? Let's say we have initial request in WLS and during request processing some service is using apache or jersey client to make an outbound call. I'm wondering if auto-instrumentation can pass traceparent/tracestate, B3 or some other standard tracing headers into such outbound calls from initial request?

[jkwatson]

Yes, definitely. This is expected and intended behavior.

[mityayak]

Is it configured somewhere? Like list of headers which are propagated if present on initial request

[jkwatson]

https://github.com/open-telemetry/opentelemetry-java/tree/main/sdk-extensions/autoconfigure#propagator is the documentation on propagation options.

[mityayak]

Thanks, that's what I was looking for! Can we add a list custom headers via configuration? let's say it's not part of existing propagators headers

[jkwatson]

No, that is not a thing that is supported. If you want to propagate addtional headers, you would need to write a custom propagator for that.