Include service.environment on spans

[roncohen]

Today we don't include service.environment on spans. We do include service.name. Unfortunately, due to the existence of service.environment, using only service.name does not fully identify a service. We should add service.environment so it's also included in all spans.

[simitt]

At the moment service.name can be overwritten on a per event basis in the Intake API. I assume adding service.environment to a span also requires allowing to overwrite this property, as it could lead to inconsistent service data otherwise. @felixbarny afair you have been asking for overwriting fields back then, do you agree on allowing to overwrite per event?

Update: the environment would most probably be the same per request, so ignore this comment.

[felixbarny]

There’s no option in the Java agent to allow for multiple environments in one JVM and we don’t have plans for that.