[metrics/system] Remove shared from system.memory.state values (#933)

Signed-off-by: ChrsMark <chrismarkou92@gmail.com>

.chloggen/decouple_shared_memory_metric.yaml

@@ -0,0 +1,22 @@
+# Use this changelog template to create an entry for release notes.
+#
+# If your change doesn't affect end users you should instead start
+# your pull request title with [chore] or use the "Skip Changelog" label.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: 'breaking'
+
+# The name of the area of concern in the attributes-registry, (e.g. http, cloud, db)
+component: system
+
+# A brief description of the change. Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Deprecate `shared` from `system.memory.state` values and make it a standalone metric
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+# The values here must be integers.
+issues: [522]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:

docs/attributes-registry/system.md

@@ -52,7 +52,7 @@
 |---|---|---|
 | `used` | used | ![Experimental](https://img.shields.io/badge/-experimental-blue) |
 | `free` | free | ![Experimental](https://img.shields.io/badge/-experimental-blue) |
-| `shared` | shared | ![Experimental](https://img.shields.io/badge/-experimental-blue) |
+| `shared` | shared | ![Deprecated](https://img.shields.io/badge/-deprecated-red)<br>Removed, report shared memory usage with `metric.system.memory.shared` metric |
 | `buffers` | buffers | ![Experimental](https://img.shields.io/badge/-experimental-blue) |
 | `cached` | cached | ![Experimental](https://img.shields.io/badge/-experimental-blue) |
 <!-- endsemconv -->

docs/system/system-metrics.md

@@ -30,6 +30,7 @@ Resource attributes related to a host, SHOULD be reported under the `host.*` nam
 - [Memory Metrics](#memory-metrics)
   - [Metric: `system.memory.usage`](#metric-systemmemoryusage)
   - [Metric: `system.memory.limit`](#metric-systemmemorylimit)
+  - [Metric: `system.memory.shared`](#metric-systemmemoryshared)
   - [Metric: `system.memory.utilization`](#metric-systemmemoryutilization)
 - [Paging/Swap Metrics](#pagingswap-metrics)
   - [Metric: `system.paging.usage`](#metric-systempagingusage)
@@ -202,7 +203,7 @@ available on the system, that is `system.memory.limit`.
 |---|---|---|
 | `used` | used | ![Experimental](https://img.shields.io/badge/-experimental-blue) |
 | `free` | free | ![Experimental](https://img.shields.io/badge/-experimental-blue) |
-| `shared` | shared | ![Experimental](https://img.shields.io/badge/-experimental-blue) |
+| `shared` | shared | ![Deprecated](https://img.shields.io/badge/-deprecated-red)<br>Removed, report shared memory usage with `metric.system.memory.shared` metric |
 | `buffers` | buffers | ![Experimental](https://img.shields.io/badge/-experimental-blue) |
 | `cached` | cached | ![Experimental](https://img.shields.io/badge/-experimental-blue) |
 <!-- endsemconv -->
@@ -222,6 +223,22 @@ This metric is [opt-in][MetricOptIn].
 <!-- semconv metric.system.memory.limit(full) -->
 <!-- endsemconv -->
 
+### Metric: `system.memory.shared`
+
+This metric is [opt-in][MetricOptIn].
+
+<!-- semconv metric.system.memory.shared(metric_table) -->
+| Name     | Instrument Type | Unit (UCUM) | Description    | Stability |
+| -------- | --------------- | ----------- | -------------- | --------- |
+| `system.memory.shared` | UpDownCounter | `By` | Shared memory used (mostly by tmpfs). [1] | ![Experimental](https://img.shields.io/badge/-experimental-blue) |
+
+**[1]:** Equivalent of `shared` from [`free` command](https://man7.org/linux/man-pages/man1/free.1.html) or
+`Shmem` from [`/proc/meminfo`](https://man7.org/linux/man-pages/man5/proc.5.html)"
+<!-- endsemconv -->
+
+<!-- semconv metric.system.memory.shared(full) -->
+<!-- endsemconv -->
+
 ### Metric: `system.memory.utilization`
 
 This metric is [recommended][MetricRecommended].
@@ -243,7 +260,7 @@ This metric is [recommended][MetricRecommended].
 |---|---|---|
 | `used` | used | ![Experimental](https://img.shields.io/badge/-experimental-blue) |
 | `free` | free | ![Experimental](https://img.shields.io/badge/-experimental-blue) |
-| `shared` | shared | ![Experimental](https://img.shields.io/badge/-experimental-blue) |
+| `shared` | shared | ![Deprecated](https://img.shields.io/badge/-deprecated-red)<br>Removed, report shared memory usage with `metric.system.memory.shared` metric |
 | `buffers` | buffers | ![Experimental](https://img.shields.io/badge/-experimental-blue) |
 | `cached` | cached | ![Experimental](https://img.shields.io/badge/-experimental-blue) |
 <!-- endsemconv -->

model/metrics/system-metrics.yaml

@@ -77,6 +77,17 @@ groups:
     unit: "By"
     attributes: []
 
+  - id: metric.system.memory.shared
+    type: metric
+    metric_name: system.memory.shared
+    stability: experimental
+    brief: "Shared memory used (mostly by tmpfs)."
+    note: |
+      Equivalent of `shared` from [`free` command](https://man7.org/linux/man-pages/man1/free.1.html) or
+      `Shmem` from [`/proc/meminfo`](https://man7.org/linux/man-pages/man5/proc.5.html)"
+    instrument: updowncounter
+    unit: "By"
+
   - id: metric.system.memory.utilization
     type: metric
     metric_name: system.memory.utilization

model/registry/system.yaml

@@ -68,6 +68,7 @@ groups:
             - id: shared
               value: 'shared'
               stability: experimental
+              deprecated: 'Removed, report shared memory usage with `metric.system.memory.shared` metric'
             - id: buffers
               value: 'buffers'
               stability: experimental