Revert breaking changes

CHANGELOG.md

@@ -29,8 +29,6 @@ release.
     - `type` to `process.context_switch_type`
   - Rename attributes for `process.paging.faults`
     - `type` to `process.paging.fault_type`
-  - Link to proposal for gRPC metrics
-    ([#627](https://github.com/open-telemetry/semantic-conventions/pull/627))
 
 ### Features
 

docs/attributes-registry/rpc.md

@@ -22,7 +22,7 @@ RPC attributes are intended to be used in the context of events related to remot
 | `rpc.jsonrpc.version` | string | Protocol version as in `jsonrpc` property of request/response. Since JSON-RPC 1.0 doesn't specify this, the value can be omitted. | `2.0`; `1.0` |
 | `rpc.method` | string | The name of the (logical) method being called, must be equal to the $method part in the span name. [5] | `exampleMethod` |
 | `rpc.service` | string | The full (logical) name of the service being called, including its package name, if applicable. [6] | `myservice.EchoService` |
-| `rpc.system` | string | A string identifying the remoting system. See below for a list of well-known identifiers. | `java_rmi` |
+| `rpc.system` | string | A string identifying the remoting system. See below for a list of well-known identifiers. | `grpc` |
 
 **[1]:** Instrumentations SHOULD require an explicit configuration of which metadata values are to be captured. Including all request metadata values can be a security risk - explicit configuration helps avoid leaking sensitive information.
 
@@ -83,6 +83,7 @@ RPC attributes are intended to be used in the context of events related to remot
 
 | Value  | Description |
 |---|---|
+| `grpc` | gRPC |
 | `java_rmi` | Java RMI |
 | `dotnet_wcf` | .NET WCF |
 | `apache_dubbo` | Apache Dubbo |

docs/rpc/README.md

@@ -20,6 +20,7 @@ Semantic conventions for RPC are defined for the following signals:
 Technology specific semantic conventions are defined for the following RPC systems:
 
 * [Connect](connect-rpc.md): Semantic Conventions for *Connect RPC*.
+* [gRPC](grpc.md): Semantic Conventions for *gRPC*.
 * [JSON-RPC](json-rpc.md): Semantic Conventions for *JSON-RPC*.
 
 Specifications defined by maintainers of RPC systems:

docs/rpc/rpc-metrics.md

@@ -60,13 +60,6 @@ metrics can be filtered for finer grain analysis.
 > * SHOULD maintain (security patching at a minimum) the existing major version
 >   for at least six months after it starts emitting both sets of conventions.
 > * SHOULD drop the environment variable in the next major version.
->
-> **Note**
-> Maintainers of gRPC have decided to create a different
-> [spec](https://github.com/grpc/proposal/blob/master/A66-otel-stats.md) due to
-> limitations on what information can be recorded by the various implementations
-> of gRPC and differences in concepts such as a `call` and an `attempt` compared
-> to other RPC systems.
 
 ## Metric instruments
 
@@ -230,7 +223,7 @@ measurements.
 | [`network.type`](../attributes-registry/network.md) | string | [OSI network layer](https://osi-model.com/network-layer/) or non-OSI equivalent. [2] | `ipv4`; `ipv6` | Recommended |
 | [`rpc.method`](../attributes-registry/rpc.md) | string | The name of the (logical) method being called, must be equal to the $method part in the span name. [3] | `exampleMethod` | Recommended |
 | [`rpc.service`](../attributes-registry/rpc.md) | string | The full (logical) name of the service being called, including its package name, if applicable. [4] | `myservice.EchoService` | Recommended |
-| [`rpc.system`](../attributes-registry/rpc.md) | string | A string identifying the remoting system. See below for a list of well-known identifiers. | `java_rmi` | Required |
+| [`rpc.system`](../attributes-registry/rpc.md) | string | A string identifying the remoting system. See below for a list of well-known identifiers. | `grpc` | Required |
 | [`server.address`](../attributes-registry/server.md) | string | Server domain name if available without reverse DNS lookup; otherwise, IP address or Unix domain socket name. [5] | `example.com`; `10.1.2.80`; `/tmp/my.sock` | Recommended |
 | [`server.port`](../attributes-registry/server.md) | int | Server port number. [6] | `80`; `8080`; `443` | Recommended |
 
@@ -270,6 +263,7 @@ different processes could be listening on TCP port 12345 and UDP port 12345.
 
 | Value  | Description |
 |---|---|
+| `grpc` | gRPC |
 | `java_rmi` | Java RMI |
 | `dotnet_wcf` | .NET WCF |
 | `apache_dubbo` | Apache Dubbo |
@@ -291,6 +285,7 @@ One process can expose multiple RPC endpoints and thus have multiple RPC service
 More specific Semantic Conventions are defined for the following RPC technologies:
 
 * [Connect](connect-rpc.md): Semantic Conventions for *Connect RPC*.
+* [gRPC](grpc.md): Semantic Conventions for *gRPC*.
 * [JSON-RPC](json-rpc.md): Semantic Conventions for *JSON-RPC*.
 
 Specifications defined by maintainers of RPC systems:

docs/rpc/rpc-spans.md

@@ -88,7 +88,7 @@ Examples of span names:
 | [`network.type`](../attributes-registry/network.md) | string | [OSI network layer](https://osi-model.com/network-layer/) or non-OSI equivalent. [2] | `ipv4`; `ipv6` | Recommended |
 | [`rpc.method`](../attributes-registry/rpc.md) | string | The name of the (logical) method being called, must be equal to the $method part in the span name. [3] | `exampleMethod` | Recommended |
 | [`rpc.service`](../attributes-registry/rpc.md) | string | The full (logical) name of the service being called, including its package name, if applicable. [4] | `myservice.EchoService` | Recommended |
-| [`rpc.system`](../attributes-registry/rpc.md) | string | A string identifying the remoting system. See below for a list of well-known identifiers. | `java_rmi` | Required |
+| [`rpc.system`](../attributes-registry/rpc.md) | string | A string identifying the remoting system. See below for a list of well-known identifiers. | `grpc` | Required |
 | [`server.address`](../attributes-registry/server.md) | string | RPC server [host name](https://grpc.github.io/grpc/core/md_doc_naming.html). [5] | `example.com`; `10.1.2.80`; `/tmp/my.sock` | Required |
 | [`server.port`](../attributes-registry/server.md) | int | Server port number. [6] | `80`; `8080`; `443` | Conditionally Required: [7] |
 
@@ -130,6 +130,7 @@ different processes could be listening on TCP port 12345 and UDP port 12345.
 
 | Value  | Description |
 |---|---|
+| `grpc` | gRPC |
 | `java_rmi` | Java RMI |
 | `dotnet_wcf` | .NET WCF |
 | `apache_dubbo` | Apache Dubbo |

model/registry/rpc.yaml

@@ -173,6 +173,9 @@ groups:
         type:
           allow_custom_values: true
           members:
+            - id: grpc
+              value: 'grpc'
+              brief: 'gRPC'
             - id: java_rmi
               value: 'java_rmi'
               brief: 'Java RMI'