Add experimental HTTP attributes to HTTP spans (#989)

.chloggen/989.yaml

@@ -0,0 +1,7 @@
+change_type: enhancement
+
+component: http
+
+note: List experimental HTTP attributes applicable to HTTP client and server spans.
+
+issues: [989]

docs/http/http-spans.md

@@ -4,7 +4,7 @@ linkTitle: Spans
 
 # Semantic Conventions for HTTP Spans
 
-**Status**: [Stable][DocumentStatus]
+**Status**: [Stable][DocumentStatus], Unless otherwise specified.
 
 This document defines semantic conventions for HTTP client and server Spans.
 They can be used for http and https schemes
@@ -17,14 +17,16 @@ and various HTTP versions like 1.1, 2 and SPDY.
 - [Name](#name)
 - [Status](#status)
 - [HTTP client](#http-client)
+  - [HTTP client experimental attributes](#http-client-experimental-attributes)
   - [HTTP client span duration](#http-client-span-duration)
   - [HTTP request retries and redirects](#http-request-retries-and-redirects)
 - [HTTP server](#http-server)
   - [HTTP server definitions](#http-server-definitions)
     - [Setting `server.address` and `server.port` attributes](#setting-serveraddress-and-serverport-attributes)
     - [Simple client/server example](#simple-clientserver-example)
     - [Client/server example with reverse proxy](#clientserver-example-with-reverse-proxy)
-  - [HTTP Server semantic conventions](#http-server-semantic-conventions)
+  - [HTTP server semantic conventions](#http-server-semantic-conventions)
+  - [HTTP server experimental attributes](#http-server-experimental-attributes)
 - [Examples](#examples)
   - [HTTP client-server example](#http-client-server-example)
   - [HTTP client retries examples](#http-client-retries-examples)
@@ -240,6 +242,21 @@ The following attributes can be important for making sampling decisions and SHOU
 | `unix` | Unix domain socket | ![Stable](https://img.shields.io/badge/-stable-lightgreen) |
 <!-- endsemconv -->
 
+### HTTP client experimental attributes
+
+**Status**: [Experimental][DocumentStatus]
+
+Instrumentations MAY allow users to enable additional experimental attributes.
+
+<!-- semconv trace.http.client.experimental(full) -->
+| Attribute  | Type | Description  | Examples  | [Requirement Level](https://opentelemetry.io/docs/specs/semconv/general/attribute-requirement-level/) | Stability |
+|---|---|---|---|---|---|
+| [`http.request.body.size`](/docs/attributes-registry/http.md) | int | The size of the request payload body in bytes. This is the number of bytes transferred excluding headers and is often, but not always, present as the [Content-Length](https://www.rfc-editor.org/rfc/rfc9110.html#field.content-length) header. For requests using transport encoding, this should be the compressed size. | `3495` | `Opt-In` | ![Experimental](https://img.shields.io/badge/-experimental-blue) |
+| [`http.request.size`](/docs/attributes-registry/http.md) | int | The total size of the request in bytes. This should be the total number of bytes sent over the wire, including the request line (HTTP/1.1), framing (HTTP/2 and HTTP/3), headers, and request body if any. | `1437` | `Opt-In` | ![Experimental](https://img.shields.io/badge/-experimental-blue) |
+| [`http.response.body.size`](/docs/attributes-registry/http.md) | int | The size of the response payload body in bytes. This is the number of bytes transferred excluding headers and is often, but not always, present as the [Content-Length](https://www.rfc-editor.org/rfc/rfc9110.html#field.content-length) header. For requests using transport encoding, this should be the compressed size. | `3495` | `Opt-In` | ![Experimental](https://img.shields.io/badge/-experimental-blue) |
+| [`http.response.size`](/docs/attributes-registry/http.md) | int | The total size of the response in bytes. This should be the total number of bytes sent over the wire, including the status line (HTTP/1.1), framing (HTTP/2 and HTTP/3), headers, and response body and trailers if any. | `1437` | `Opt-In` | ![Experimental](https://img.shields.io/badge/-experimental-blue) |
+<!-- endsemconv -->
+
 ### HTTP client span duration
 
 There are some minimal constraints that SHOULD be honored:
@@ -314,7 +331,7 @@ Application developers MAY overwrite potentially inaccurate values of `server.*`
 [Forwarded#host]: https://developer.mozilla.org/docs/Web/HTTP/Headers/Forwarded#host
 [X-Forwarded-Host]: https://developer.mozilla.org/docs/Web/HTTP/Headers/X-Forwarded-Host
 
-### HTTP Server semantic conventions
+### HTTP server semantic conventions
 
 This span type represents an inbound HTTP request.
 
@@ -458,6 +475,21 @@ The following attributes can be important for making sampling decisions and SHOU
 
 `http.route` MUST be provided at span creation time if and only if it's already available. If it becomes available after span starts, instrumentation MUST populate it anytime before span ends.
 
+### HTTP server experimental attributes
+
+**Status**: [Experimental][DocumentStatus]
+
+Instrumentations MAY allow users to enable additional experimental attributes.
+
+<!-- semconv trace.http.server.experimental(full) -->
+| Attribute  | Type | Description  | Examples  | [Requirement Level](https://opentelemetry.io/docs/specs/semconv/general/attribute-requirement-level/) | Stability |
+|---|---|---|---|---|---|
+| [`http.request.body.size`](/docs/attributes-registry/http.md) | int | The size of the request payload body in bytes. This is the number of bytes transferred excluding headers and is often, but not always, present as the [Content-Length](https://www.rfc-editor.org/rfc/rfc9110.html#field.content-length) header. For requests using transport encoding, this should be the compressed size. | `3495` | `Opt-In` | ![Experimental](https://img.shields.io/badge/-experimental-blue) |
+| [`http.request.size`](/docs/attributes-registry/http.md) | int | The total size of the request in bytes. This should be the total number of bytes sent over the wire, including the request line (HTTP/1.1), framing (HTTP/2 and HTTP/3), headers, and request body if any. | `1437` | `Opt-In` | ![Experimental](https://img.shields.io/badge/-experimental-blue) |
+| [`http.response.body.size`](/docs/attributes-registry/http.md) | int | The size of the response payload body in bytes. This is the number of bytes transferred excluding headers and is often, but not always, present as the [Content-Length](https://www.rfc-editor.org/rfc/rfc9110.html#field.content-length) header. For requests using transport encoding, this should be the compressed size. | `3495` | `Opt-In` | ![Experimental](https://img.shields.io/badge/-experimental-blue) |
+| [`http.response.size`](/docs/attributes-registry/http.md) | int | The total size of the response in bytes. This should be the total number of bytes sent over the wire, including the status line (HTTP/1.1), framing (HTTP/2 and HTTP/3), headers, and response body and trailers if any. | `1437` | `Opt-In` | ![Experimental](https://img.shields.io/badge/-experimental-blue) |
+<!-- endsemconv -->
+
 ## Examples
 
 ### HTTP client-server example

model/trace/http.yaml

@@ -4,6 +4,7 @@ groups:
     extends: attributes.http.client
     span_kind: client
     brief: 'Semantic Convention for HTTP Client'
+    stability: stable
     attributes:
       - ref: http.request.method
         sampling_relevant: true
@@ -37,11 +38,26 @@ groups:
           Generally `tcp` for `HTTP/1.0`, `HTTP/1.1`, and `HTTP/2`. Generally `udp` for `HTTP/3`.
           Other obscure implementations are possible.
 
+  - id: trace.http.client.experimental
+    type: attribute_group
+    brief: 'Experimental attributes for HTTP Client spans'
+    stability: experimental
+    attributes:
+      - ref: http.request.size
+        requirement_level: opt_in
+      - ref: http.response.size
+        requirement_level: opt_in
+      - ref: http.request.body.size
+        requirement_level: opt_in
+      - ref: http.response.body.size
+        requirement_level: opt_in
+
   - id: trace.http.server
     type: span
     extends: attributes.http.server
     span_kind: server
     brief: 'Semantic Convention for HTTP Server'
+    stability: stable
     attributes:
       - ref: http.request.method
         sampling_relevant: true
@@ -95,3 +111,17 @@ groups:
         note: >
           Generally `tcp` for `HTTP/1.0`, `HTTP/1.1`, and `HTTP/2`. Generally `udp` for `HTTP/3`.
           Other obscure implementations are possible.
+
+  - id: trace.http.server.experimental
+    type: attribute_group
+    brief: 'Experimental attributes for HTTP Server spans'
+    stability: experimental
+    attributes:
+      - ref: http.request.size
+        requirement_level: opt_in
+      - ref: http.response.size
+        requirement_level: opt_in
+      - ref: http.request.body.size
+        requirement_level: opt_in
+      - ref: http.response.body.size
+        requirement_level: opt_in