Add rpc.system value for Apache Dubbo

CHANGELOG.md

@@ -68,6 +68,8 @@ release.
   ([#1978](https://github.com/open-telemetry/opentelemetry-specification/pull/1978))
 - Add `process.cpu.utilization` metric.
   ([#2436](https://github.com/open-telemetry/opentelemetry-specification/pull/2436))
+- Add `rpc.system` value for Apache Dubbo.
+  ([#2453](https://github.com/open-telemetry/opentelemetry-specification/pull/2453))
 
 ### Compatibility
 

semantic_conventions/trace/rpc.yaml

@@ -19,6 +19,9 @@ groups:
             - id: dotnet_wcf
               value: 'dotnet_wcf'
               brief: '.NET WCF'
+            - id: apache_dubbo
+              value: 'apache_dubbo'
+              brief: 'Apache Dubbo'
       - id: service
         type: string
         required:

specification/metrics/semantic_conventions/rpc.md

@@ -84,6 +84,7 @@ or not they should be on the server, client or both.
 | `grpc` | gRPC |
 | `java_rmi` | Java RMI |
 | `dotnet_wcf` | .NET WCF |
+| `apache_dubbo` | Apache Dubbo |
 <!-- endsemconv -->
 
 To avoid high cardinality, implementations should prefer the most stable of `net.peer.name` or

specification/trace/semantic_conventions/rpc.md

@@ -80,6 +80,7 @@ Examples of span names:
 | `grpc` | gRPC |
 | `java_rmi` | Java RMI |
 | `dotnet_wcf` | .NET WCF |
+| `apache_dubbo` | Apache Dubbo |
 <!-- endsemconv -->
 
 For client-side spans `net.peer.port` is required if the connection is IP-based and the port is available (it describes the server port they are connecting to).