Tracing: How to add dynamic attributes to all spans?

[jbluntz]

Question

I'd like to be able to add an attribute that may change throughout the lifetime of the app to all spans logged by the SDK. I'm using OpenTelemetry so I can add tags that are static and known at initialization time via OtelTracerProvider.Builder.addTag, but this doesn't work for attributes that either aren't static or aren't known at initialization time.

I looked into SpanEventMapper but very little of the SpanEvent object is mutable (only resource and name) and the SDK drops Spans if the mapper returns a new object instead of the one that was passed in.

Is there another approach to solving this problem? If not, would you consider making SpanEvent.Meta.additionalProperties a MutableMap or exposing a setter to add properties?

[aleksandr-gringauz]

@jbluntz Thank you for your question!

Is there another approach to solving this problem?

It is possible to add attributes to an already existing span using this setAttribute method. Is it possible for you to attach the most recent values of your attributes just before you end the span?

[jbluntz]

Hi @aleksandr-gringauz; sorry for the delayed response. The problem with that approach is it has to be applied anywhere and everywhere a span is created, now and in the future. What I need is a way to guarantee that any span that is created in our app has a given attribute, but that attribute's value isn't static.

If I were using the opentelemetry-java SDK, I would use a SpanProcessor for a use case like this. I've also considered wrapping the TracerProvider that the DataDog SDK provides in our own before registering it with OpenTelemetry but this would mean spans that don't go through Otel (like those logged by the DataDog TracingInterceptor we use in our OkHttpClient) would be missing these attributes.

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[aleksandr-gringauz]

@jbluntz

Sorry for a late reply. We discussed it internally. Question - will SpanEvent.usr.additionalProperties work for you (it already exists)?

Thank you.

[jbluntz]

Unfortunately not- it would be functional but these properties aren't really attributes of the user, per se. I need to align to the semantic conventions established at my company, which puts these attributes in a specific namespace (eg company.conversation.id).

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This issue has been automatically marked as stale because it has not had recent activity and has the awaiting-response label.

It will be closed if no further activity occurs within 3 days.