BREAKING: Change span statuses for gRPC server spans (open-telemetry#…

…3333)

Fixes open-telemetry#3110

## Changes

The idea behind the PR is to make the spam statuses gRPC convention
similar to HTTP semantic conventions.
The gRPC statuses -> HTTP status codes mapping is not anywhere strictly
defined.
However, there is are some approximations which can be found:

-
grpc/grpc@bb04e07#diff-c94ff143c8f378e6925a985fa18528a8254a6d7fc34bc855e1de13f1e7f3e464
-
https://github.com/googleapis/googleapis/blob/master/google/rpc/code.proto

I got confused if we should treat `INTERNAL` as `Error` for
`SpanKind.SERVER` because of:

-
https://github.com/grpc/grpc/blob/master/doc/http-grpc-status-mapping.md
-
https://github.com/grpc/grpc-go/blob/a02aae6168aa683a1f106e285ec10eb6bc1f6ded/internal/transport/handler_server.go#L90C8-L92
-
https://github.com/grpc/grpc-go/blob/a02aae6168aa683a1f106e285ec10eb6bc1f6ded/internal/transport/http_util.go#L73

On the other hand, [the
description](https://github.com/grpc/grpc/blob/master/doc/statuscodes.md)
of `INTERNAL` says:

> Internal errors. This means that some invariants expected by the
underlying system have been broken. This error code is reserved for
serious errors.

Therefore, I decided to leave it as `Error`. Also because this is
backwards compatible (at least for this gRPC status).

---------

Co-authored-by: Tyler Yahn <[email protected]>

CHANGELOG.md

@@ -56,6 +56,8 @@ release.
   ([#3097](https://github.com/open-telemetry/opentelemetry-specification/pull/3097))
 - Clarify stability requirements of semantic conventions
   ([#3225](https://github.com/open-telemetry/opentelemetry-specification/pull/3225))
+- BREAKING: Change span statuses for gRPC server spans.
+  ([#3333](https://github.com/open-telemetry/opentelemetry-specification/pull/3333))
 
 ### Compatibility
 

specification/trace/semantic_conventions/rpc.md

@@ -206,7 +206,31 @@ For remote procedure calls via [gRPC][], additional conventions are described in
 
 ### gRPC Status
 
-The [Span Status](../api.md#set-status) MUST be left unset for an `OK` gRPC status code, and set to `Error` for all others.
+The table below describes when
+the [Span Status](../api.md#set-status) MUST be set
+to `Error` or remain unset
+depending on the [gRPC status code](https://github.com/grpc/grpc/blob/v1.33.2/doc/statuscodes.md)
+and [Span Kind](../api.md#spankind).
+
+| gRPC Status Code | `SpanKind.SERVER` Span Status | `SpanKind.CLIENT` Span Status |
+|---|---|---|
+| OK | unset | unset |
+| CANCELLED | unset | `Error` |
+| UNKNOWN | `Error` | `Error`  |
+| INVALID_ARGUMENT | unset | `Error` |
+| DEADLINE_EXCEEDED | `Error` | `Error` |
+| NOT_FOUND | unset | `Error` |
+| ALREADY_EXISTS | unset | `Error` |
+| PERMISSION_DENIED | unset | `Error` |
+| RESOURCE_EXHAUSTED | unset| `Error` |
+| FAILED_PRECONDITION | unset | `Error` |
+| ABORTED | unset | `Error` |
+| OUT_OF_RANGE | unset | `Error` |
+| UNIMPLEMENTED | `Error` | `Error` |
+| INTERNAL | `Error` | `Error` |
+| UNAVAILABLE | `Error` | `Error` |
+| DATA_LOSS | `Error` | `Error` |
+| UNAUTHENTICATED | unset | `Error` |
 
 ### gRPC Request and Response Metadata