Allow to set span's Status

[iNikem]

OpenTelemetry spec currently says the following in the description of Span.SetStatus method:

Application developers and Operators may set the status code to Ok.

From the previous discussions on this topic I assumed that the way for Operator to set span status is by using Collector. Unfortunately, Collector does not support setting span status atm. Span Processor supports only changing span name and Attributes Processor, naturally, operate only on attributes and cannot change status.

Proposed solution is to expand Span Processor and to allow it to change span status.

[billg-splunk]

It seems like a pretty big deal to be able to support this. In some contexts a 4xx error is not considered an error. But with no way to easily alter the status it causes an error behavior regardless. This brings with it false-positives.

[jshawatsplunk]

I too have users who do not consider 4xx as errors of interest. Control over such configuration would be very welcomed.

[kdroukman]

Adding my vote to this. The rigid specification around the span status doesn't allow for a variety of use cases in the real world, with the most common request being the ability to override error classification of 4xx status codes.

[iNikem]

@bogdandrutu why did you move this issue into contrib? Changing attribute values is the core functionality of the Collector. Changing status value should be the same, no?

[TomRoSystems]

Please assign this ticket to me.

[iNikem]

Fixed by #5886