feat: Add process.network.connection.count metric definition

Adds a new metric that reports the number of established network
connections per process, grouped by server address and port.

- Metric type: updowncounter, unit: {connection}
- Attributes: server.address (recommended), server.port (recommended)
- Entity: process
- Stability: development

Assisted-by: Claude Opus 4.8

Author: GlqEason

.chloggen/feat-process-network-connection-metric.yaml

@@ -0,0 +1,10 @@
+# This file is used by the changelog generator.
+# For more info, see https://github.com/open-telemetry/weaver/releases
+
+change_type: new_component
+component: process
+note: Add process.network.connection.count metric definition
+issues: []
+subtext: |
+  Adds a new metric that reports the number of established network connections
+  per process, grouped by server address and port.

docs/system/process-metrics.md

@@ -24,6 +24,7 @@ metrics](/docs/runtime/README.md#metrics).
   - [Metric: `process.memory.virtual`](#metric-processmemoryvirtual)
   - [Metric: `process.disk.io`](#metric-processdiskio)
   - [Metric: `process.network.io`](#metric-processnetworkio)
+  - [Metric: `process.network.connection.count`](#metric-processnetworkconnectioncount)
   - [Metric: `process.thread.count`](#metric-processthreadcount)
   - [Metric: `process.unix.file_descriptor.count`](#metric-processunixfile_descriptorcount)
   - [Metric: `process.windows.handle.count`](#metric-processwindowshandlecount)
@@ -222,6 +223,31 @@ This metric is [recommended][MetricRecommended].
 <!-- END AUTOGENERATED TEXT -->
 <!-- endsemconv -->
 
+### Metric: `process.network.connection.count`
+
+This metric is [opt-in][MetricOptIn].
+
+<!-- semconv metric.process.network.connection.count -->
+<!-- NOTE: THIS TEXT IS AUTOGENERATED. DO NOT EDIT BY HAND. -->
+<!-- see templates/registry/markdown/snippet.md.j2 -->
+<!-- prettier-ignore-start -->
+
+| Name | Instrument Type | Unit (UCUM) | Description | Stability | Entity Associations |
+| -------- | --------------- | ----------- | -------------- | --------- | ------ |
+| `process.network.connection.count` | UpDownCounter | `{connection}` | The number of network connections established by the process, grouped by the remote endpoint. | ![Development](https://img.shields.io/badge/-development-blue) | [`process`](/docs/registry/entities/process.md#process) |
+
+**Attributes:**
+
+| Key | Stability | [Requirement Level](https://opentelemetry.io/docs/specs/semconv/general/attribute-requirement-level/) | Value Type | Description | Example Values |
+| --- | --- | --- | --- | --- | --- |
+| [`server.address`](/docs/registry/attributes/server.md) | ![Stable](https://img.shields.io/badge/-stable-lightgreen) | `Recommended` | string | Server domain name if available without reverse DNS lookup; otherwise, IP address or Unix domain socket name. | `example.com`; `10.1.2.80` |
+| [`server.port`](/docs/registry/attributes/server.md) | ![Stable](https://img.shields.io/badge/-stable-lightgreen) | `Recommended` | int | Server port number. | `80`; `443` |
+
+---
+<!-- prettier-ignore-end -->
+<!-- END AUTOGENERATED TEXT -->
+<!-- endsemconv -->
+
 ### Metric: `process.thread.count`
 
 This metric is [recommended][MetricRecommended].

model/process/metrics.yaml

@@ -195,3 +195,21 @@ groups:
     unit: "s"
     entity_associations:
       - process
+
+  - id: metric.process.network.connection.count
+    type: metric
+    metric_name: process.network.connection.count
+    annotations:
+      code_generation:
+        metric_value_type: int
+    stability: development
+    brief: "The number of network connections established by the process, grouped by the remote endpoint."
+    instrument: updowncounter
+    unit: "{connection}"
+    attributes:
+      - ref: server.address
+        requirement_level: recommended
+      - ref: server.port
+        requirement_level: recommended
+    entity_associations:
+      - process