[QUERY] Export trace events as Event Telemetry

Library name and version

Azure.Monitor.OpenTelemetry.Exporter 1.0.0-beta.8

Query/Question

In a .Net 6 Web Api controller action I added an event to the current span with the expectation it would end up as an event in Application Insights. The following code is executed

Tracer.CurrentSpan.AddEvent("Event");

However, it ends up as a trace in Application Insights. Looking at the code of the exporter it seems events have no place (yet). Is this by design?

Environment

No response

[Expecho]

@vishweshbankwar First of all, thank you for taking time to react to my query. I am sorry to see it is closed immediately as I have a follow-up question and proposal. For a starter, can you explain what you mean with “There is no equivalent for CustomEvents available right now.”?

I assume it has to do with the fact that according to the OTEL spec events are just a special type of LogRecords but in the context of Application Insights (AI) it would make sense to export them as a CustomEvents record. I have a lot of applications that are instrumented using the AI SDK. For new applications I am tempted to use the OTEL SDK as it gives us more flexibility regarding the backend of our traces.

For now we do use the Events telemetry type a lot, given the way they can be analyzed in AI. How about making it optional (and disabled by default) to export events as CustomEvents? Also, given the current state it is near impossible to distinct a trace from an event in AI. I hope you see the reasoning behind my question.

I would be more than happy to draft out a PR to facilitate this using the AzureMonitorExporterOptions or any other way you might seem as a better fit.

(If you rather want me to create a new issue for this, please let me know)

[mattmccleary]

Hi Peter,

I appreciate your feedback.

We use it to log business events, like “Invoice Downloaded”. According to the docs this is what events should be used for. I got the feeling this is not the case when OTEL is used. What is your thought about that?

Not today, though the OTel community understands the need for these kinds of business events. The question is whether it should be an extension to existing language logging APIs or an altogether new OpenTelemetry events API. Does this make a difference to you or is it just technical jargon? (i.e., just give me a way)

In the meantime as Azure we need to decide if our OpenTelemetry Distro should wait for OTel to catch up or if we should build some sort of temporary back compat shim that temporarily supports Track.Event from the App Insights API. If Azure offered some sort of temporary vender-specific business events OTel extension, would you be interested?

If you go ahead and build your own mechanism, would it be a custom SDK? Would you still drop your events in Azure? Would would be the reporting experience? Is this something you’d switch over to OTel standard in the future when available?