OTelHttp client metrics are not recorded in case of an error when handling the round trip

[AyseGokmen]

Description

OTelHttp client metrics have no way to record the error because it exists early when handling errors.

opentelemetry-go-contrib/instrumentation/net/http/otelhttp/transport.go

Line 144 in e671155

return res, err

Environment

• OS: macOS
• Architecture: arm64
• Go Version: 1.24
• otelhttp version: v0.60.0

Steps To Reproduce

1. Send a http request using otelhttp transport which would timeout
2. Observe that http.client.request.duration metric is not recorded.

Expected behavior

• http.client.request.duration should still be recorded when an error happens during the round trip like timeouts.
• http.client.request.duration should have the error.type attribute set when a net.http or other type of error happens during the transport round trip.

[alimikegami]

Hi, can I contribute to this issue? This would be my first time contributing to open source, and I would appreciate any guidance

[alimikegami]

Thank you! @dmathieu

[alimikegami]

Hi @dmathieu @AyseGokmen,

I have a question regarding this point:

http.client.request.duration should have the error.type attribute set when a net.http or other type of error occurs during the transport round trip.

I've read the code and tried to find a function that allows me to set the error.type attribute, but I couldn't find one. Does this mean I need to implement a function to set this attribute myself? Could you please confirm if this is the expected approach?

Thank you.

[hostejulien]

Hi, I’m not a maintainer, but I looked into this and wanted to share my findings:

You shouldn’t need to implement a custom function, as the existing code already sets the error.type attribute using span.SetAttributes(errType) when the error matches a predefined type. See the relevant code here.

Hope this helps!

[AyseGokmen]

Logic to set the error type is here

[alimikegami]

Thank you! @hostejulien @AyseGokmen