Change network.transport from recommended to opt-in in the HTTP semconv

CHANGELOG.md

@@ -7,6 +7,9 @@ release.
 
 ## Unreleased
 
+- Remove `network.protocol.name` from HTTP semconv.
+  ([#402](https://github.com/open-telemetry/semantic-conventions/pull/402))
+
 ### Breaking
 
 ### Features

docs/http/http-spans.md

@@ -125,8 +125,7 @@ sections below.
 | [`http.response.status_code`](../attributes-registry/http.md) | int | [HTTP response status code](https://tools.ietf.org/html/rfc7231#section-6). | `200` | Conditionally Required: If and only if one was received/sent. |
 | [`network.protocol.name`](../general/attributes.md) | string | [OSI application layer](https://osi-model.com/application-layer/) or non-OSI equivalent. [6] | `http`; `spdy` | Recommended: if not default (`http`). |
 | [`network.protocol.version`](../general/attributes.md) | string | Version of the protocol specified in `network.protocol.name`. [7] | `1.0`; `1.1`; `2`; `3` | Recommended |
-| [`network.transport`](../general/attributes.md) | string | [OSI transport layer](https://osi-model.com/transport-layer/) or [inter-process communication method](https://en.wikipedia.org/wiki/Inter-process_communication). [8] | `tcp`; `udp` | Conditionally Required: [9] |
-| [`network.type`](../general/attributes.md) | string | [OSI network layer](https://osi-model.com/network-layer/) or non-OSI equivalent. [10] | `ipv4`; `ipv6` | Recommended |
+| [`network.type`](../general/attributes.md) | string | [OSI network layer](https://osi-model.com/network-layer/) or non-OSI equivalent. [8] | `ipv4`; `ipv6` | Recommended |
 | `user_agent.original` | string | Value of the [HTTP User-Agent](https://www.rfc-editor.org/rfc/rfc9110.html#field.user-agent) header sent by the client. | `CERN-LineMode/2.15 libwww/2.17b3` | Recommended |
 
 **[1]:** If the request fails with an error before response status code was sent or received,
@@ -176,14 +175,6 @@ The attribute value MUST consist of either multiple header values as an array of
 
 **[8]:** The value SHOULD be normalized to lowercase.
 
-Consider always setting the transport when setting a port number, since
-a port number is ambiguous without knowing the transport, for example
-different processes could be listening on TCP port 12345 and UDP port 12345.
-
-**[9]:** If not default (`tcp` for `HTTP/1.1` and `HTTP/2`, `udp` for `HTTP/3`).
-
-**[10]:** The value SHOULD be normalized to lowercase.
-
 Following attributes MUST be provided **at span creation time** (when provided at all), so they can be considered for sampling decisions:
 
 * [`http.request.method`](../attributes-registry/http.md)
@@ -209,15 +200,6 @@ Following attributes MUST be provided **at span creation time** (when provided a
 | `TRACE` | TRACE method. |
 | `_OTHER` | Any HTTP method that the instrumentation has no prior knowledge of. |
 
-`network.transport` has the following list of well-known values. If one of them applies, then the respective value MUST be used, otherwise a custom value MAY be used.
-
-| Value  | Description |
-|---|---|
-| `tcp` | TCP |
-| `udp` | UDP |
-| `pipe` | Named or anonymous pipe. See note below. |
-| `unix` | Unix domain socket |
-
 `network.type` has the following list of well-known values. If one of them applies, then the respective value MUST be used, otherwise a custom value MAY be used.
 
 | Value  | Description |

model/trace/http.yaml

@@ -19,9 +19,6 @@ groups:
       - ref: http.request.method
         sampling_relevant: true
         requirement_level: required
-      - ref: network.transport
-        requirement_level:
-          conditionally_required: If not default (`tcp` for `HTTP/1.1` and `HTTP/2`, `udp` for `HTTP/3`).
       - ref: network.type
       - ref: user_agent.original