Telemetry Context

[js10x]

I'd like to opt out of using telemetry, how can I disable it when using the UA stack for .NET? I've noticed that none of the ITelemetryContext objects are nullable or did I miss something, so sending null as the value could cause issues?

I'm assuming the best way to turn off telemetry is to pass a null logger factory like so. Curious if this is not conforming to best practices or proper design of the UA stack?

`
public class NullTelemetry : TelemetryContextBase
{

public NullTelemetry(): base(new NullLoggerFactory()) { }

}
`

[marcschier]

@js10x - passing null is ok (only a small part is annotated nullable, but it is also not something that is explicitly suggested by us), or -better- you pass your own NullTelemetry. But I am curious why you would not want to be able to observe your application or at least have some ability to "file a bug" if something does not work in the stack. Any specific reasons?

[js10x]

Oh ok, gotcha. Well, having worked with OpenTelemetry at my full time job, I'm aware of the hit in performance. So I'd weigh the cost vs. benefits in this case, and go with more performance then observability that I may rarely need. Now, it's entirely possible the telemetry implemented here does not follow the OpenTelemetry protocol or implement tracing with exports and providers and all that. Forgive me if I missed it, but I don't see any documentation that outlines what the telemetry implemented in the UA stack actually does. Is it only logging in critical places? Or is it more than just logging?

[romanett]

You can find more information here: basically you are good to go if you speficy a sufficient log Level: https://github.com/OPCFoundation/UA-.NETStandard/blob/master/Docs/Observability.md

[marcschier]

Yeah, maybe "Observability" immediately lands someone at OTEL as OTEL is en vogue, but OTEL is added on top because OTEL exporters just leverage the internal diagnostics infra to subscribe to meters and activity, and while we might emit more and more of those over time, You could just add prometheus and no otel, and that would work now and show the new req metrics. And if there is no listener these are just noop.

Nevertheless, you can even wire in whatever you want earlier by implementing the ITelemetryContext to your liking. But mostly you would want to wire ILoggerFactory to your logging library of choice. Examples are the nunit and benchmarknet loggerfactory in the tests, or the serilog loggerfactory in the console samples.

The interface is there to allow us to also DI enable this, and for DI to pull the registered logger, IMeter, etc. together into a common object to pass around. Or so the plan.