Automate seamless correlation with Grafana Frontend Observability

[cedricziel]

Is your feature request related to a problem? Please describe.

Grafana Frontend Observability can correlate individual page - loads and asynchronous backend calls automatically with Application Observability. The RUM and APM correlation need is pretty popular to diagnose slow loading sites and generally correlate across product areas.

However creating strong correlation, the server needs to send a response header of server-timing, containing the traceparent field of the root span. Implementing this in every service is very expensive. We should look for a solution that decreases the time to value for users and automatically inject the current traceparent for http responses.

Describe the solution you'd like

Inject a server-timing header containing the current traceparent in its description so that the Faro Web SDK can capture it from the browser performance API.

grafana/faro-web-sdk@ce86005/packages/web-sdk/src/instrumentations/performance/navigation.test.ts#L96-L109

Describe alternatives you've considered

No response

Additional context

Our Java distro for OTel does it :) - grafana/grafana-opentelemetry-java#661