Exception semantic conventions need to be marked stable

[trask]

Opening for now primarily to discuss/track whether this is a blocker for marking HTTP semantic conventions stable.

My initial thought is that we won't be able to declare HTTP instrumentations stable without this, and therefore this is a blocker for HTTP semantic convention stability.

[trask]

from @jsuereth

My main fear with current exception encoding is inetraction with the length-limit on the actual exception stacktrace string, and whether that will lead to poor experience in debugging exceptions from OTEL

[jsuereth]

Adding some more thoughts looking at specifics:

• We should add a spec compliance metrics where each language SiG can denote whether they have documented their exception.stacktrace format. This is implicitly required in the current convention. See this recommendation as an option for language SIGs.
• I'm worried about the interaction of OTEL_ATTRIBUTE_VALUE_LENGTH_LIMIT and exception.stacktrace. I'm not sure users of the value length limit would think about stacktraces as an attribute. We should entertain if we want to have some special interaction of those two or just encourage users not to set length limits, as the current default is unlimited.
• Should we ask language SiGs to update the semconv specification document with their official layout? This way the documentation for how to leverage the field is centrally located.

[reyang]

My vote: it's not blocking HTTP semantic convention.
Reason:

1. exception is not going to be part of the core HTTP metrics (so there is no concern of breaking the metrics streams)
2. exception stack should be opt-in due to the size and potential sensitive information

[trask]

until exception semantic conventions are marked stable, we cannot mark any Java HTTP instrumentations as stable.

but I agree this should not be block HTTP semantic conventions themselves from being marked stable.

[lmolkova]

exceptions are stable, https://github.com/open-telemetry/semantic-conventions/tree/main/docs/exceptions, closing