HTTP OTEL metrics: use error.type instead of exception.type attribute

[lmolkova]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

OTel recently defined error.type attribute as a general-purpose error status. It is used on http.server.* and other metrics (open-telemetry/semantic-conventions#205).

ASP.NET Core now reports exception.type on .NET-specific metrics like (kestrel.*, aspnetcore.*) as well as common HTTP metrics.

e.g. here

aspnetcore/src/Hosting/Hosting/src/Internal/HostingMetrics.cs

Line 77 in 36e03b5

tags.Add("exception.type", exception.GetType().FullName);

Reporting exception.type on common OTel metrics makes .NET incompatible with the OTel spec.

Expected Behavior

ASP.NET Core metrics in http.* namespace should use error.type attribute (populating full exception type on it, in the same was as today).
.NET-specific metrics can keep using exception.type or switch to exception.type.

Steps To Reproduce

No response

Exceptions (if any)

No response

.NET Version

8.0

[noahfalk]

@JamesNK

[JamesNK]

Lets switch to error.type everywhere.

[JamesNK]

I noticed that exception.type is still used by logging and tracing in the conventions. Is it intentional that there is a difference between metrics and other telemetry?

https://github.com/search?q=repo%3Aopen-telemetry%2Fsemantic-conventions%20%22exception.type%22&type=code

[lmolkova]

I noticed that exception.type is still used by logging and tracing in the conventions. Is it intentional that there is a difference between metrics and other telemetry?

https://github.com/search?q=repo%3Aopen-telemetry%2Fsemantic-conventions%20%22exception.type%22&type=code

from offline conversation - those are semconv for exceptions on logs/events and not for traces/metrics.
The error.type attribute is intended for traces/metrics and all sorts of errors (exceptions or not)

[JamesNK]

Fixed with #51084