Recommended pattern to override activity sources at startup

[ilya-chumakov]

What is the question?

For a configuration like this, is there a way to exclude some sources from the output after all calls to .Add__Instrumentation() have been made? For example: temporarily mute a source without having to rebuild the app.

services.AddOpenTelemetry()
	.WithTracing(builder => builder
		.AddAspNetCoreInstrumentation()
		.AddHttpClientInstrumentation()
		//...
	);

The ultimate goal is to have fine-grained control over sources per environment, without having to wrap each Add__Instrumentation() call in a conditional block (which even may not work, since multiple sources could be added to the list per such call). The source list is essentially a List<string>, but due to the multiple implementations of TracerProviderBuilder, the access to that property is not that straightforward even via reflection or type cast (which alone is a very bad practice, of course).

1. Is this list hidden by design?
2. If not, would you accept a PR adding something like a direct access to the source list?
3. Or is all of this fundamentally wrong, and would fine-grained control over sources be better implemented in another way?

Additional context

.NET 9

<PackageReference Include="OpenTelemetry" Version="1.12.0" />
<PackageReference Include="OpenTelemetry.Extensions.Hosting" Version="1.12.0" />

[Kielek]

Could you please consider Collector to manipulate your data? I think that it is most powerfully way to do this.

[ilya-chumakov]

Could you please consider Collector to manipulate your data? I think that it is most powerfully way to do this.

We considered this approach but rejected it due to the large computational and networking overhead in comparison to disabling activity sources on the app level.