Describe your environment

OS: Debian 12
Python version: Any
Package version: 0.49b0 and later

What happened?

Since 1.28.0, the opentelemetry Python SDK supports exemplars. However some instrumentation libraries does not add exemplars because the measure are added/recorded outside of the active span.

For example, in the asgi instrumentation, all measures should be taken within the use_span context rather than outside:

Steps to Reproduce

You can test the repository https://github.com/webscit/opentelemetry-demo-python with OTEL_AUTO_INSTRUMENTATION_LEVEL = 1, it uses fastapi instrumentation (but the flaw is actually in the asgi instrumentation).

Expected Result

Exemplars are recorded for all Python instrumentations

Actual Result

Some instrumentations are missing exemplars

Additional context

I don't know if all packages or only a subset of them are concerned by this. I have at least identified 3 cases:

Would you like to implement a fix?

None