From 0669ca5b81d366dc21647b8ed967194bb0868a4c Mon Sep 17 00:00:00 2001
From: Trask Stalnaker <trask.stalnaker@gmail.com>
Date: Wed, 16 Aug 2023 14:59:43 -0700
Subject: [PATCH] Add `jvm.cpu.count` metric (#52)

Co-authored-by: Armin Ruech <armin.ruech@dynatrace.com>
---
 CHANGELOG.md                                   |  2 ++
 docs/system/runtime-environment-metrics.md     | 16 ++++++++++++++++
 model/metrics/process-runtime-jvm-metrics.yaml |  7 +++++++
 3 files changed, 25 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index c8c5f52301..a79fc4b3d6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -48,6 +48,8 @@ release.
 - Clarify that `http/dup` has higher precedence than `http` in case both values are present
   in `OTEL_SEMCONV_STABILITY_OPT_IN`
   ([#249](https://github.com/open-telemetry/semantic-conventions/pull/249))
+- Add `jvm.cpu.count` metric.
+  ([#52](https://github.com/open-telemetry/semantic-conventions/pull/52))
 
 ## v1.21.0 (2023-07-13)
 
diff --git a/docs/system/runtime-environment-metrics.md b/docs/system/runtime-environment-metrics.md
index c0843daf01..b3c7b8cb88 100644
--- a/docs/system/runtime-environment-metrics.md
+++ b/docs/system/runtime-environment-metrics.md
@@ -30,6 +30,7 @@ semantic conventions when instrumenting runtime environments.
   * [Metric: `jvm.classes.unloaded`](#metric-jvmclassesunloaded)
   * [Metric: `jvm.classes.current_loaded`](#metric-jvmclassescurrent_loaded)
   * [Metric: `jvm.cpu.time`](#metric-jvmcputime)
+  * [Metric: `jvm.cpu.count`](#metric-jvmcpucount)
   * [Metric: `jvm.cpu.recent_utilization`](#metric-jvmcpurecent_utilization)
 - [JVM Metrics (Experimental)](#jvm-metrics-experimental)
   * [Metric: `jvm.memory.init`](#metric-jvmmemoryinit)
@@ -289,6 +290,21 @@ and [`com.ibm.lang.management.OperatingSystemMXBean#getProcessCpuTime()`](https:
 <!-- semconv metric.jvm.cpu.time(full) -->
 <!-- endsemconv -->
 
+### Metric: `jvm.cpu.count`
+
+This metric is [recommended][MetricRecommended].
+This metric is obtained from [`Runtime#availableProcessors()`](https://docs.oracle.com/javase/8/docs/api/java/lang/Runtime.html#availableProcessors--).
+Note that this is always an integer value (i.e. fractional or millicores are not represented).
+
+<!-- semconv metric.jvm.cpu.count(metric_table) -->
+| Name     | Instrument Type | Unit (UCUM) | Description    |
+| -------- | --------------- | ----------- | -------------- |
+| `jvm.cpu.count` | UpDownCounter | `{cpu}` | Number of processors available to the Java virtual machine. |
+<!-- endsemconv -->
+
+<!-- semconv metric.jvm.cpu.count(full) -->
+<!-- endsemconv -->
+
 ### Metric: `jvm.cpu.recent_utilization`
 
 This metric is [recommended][MetricRecommended].
diff --git a/model/metrics/process-runtime-jvm-metrics.yaml b/model/metrics/process-runtime-jvm-metrics.yaml
index d6b4c502a8..683b42ba92 100644
--- a/model/metrics/process-runtime-jvm-metrics.yaml
+++ b/model/metrics/process-runtime-jvm-metrics.yaml
@@ -114,6 +114,13 @@ groups:
     instrument: updowncounter
     unit: "{class}"
 
+  - id: metric.jvm.cpu.count
+    type: metric
+    metric_name: jvm.cpu.count
+    brief: "Number of processors available to the Java virtual machine."
+    instrument: updowncounter
+    unit: "{cpu}"
+
   - id: metric.jvm.cpu.time
     type: metric
     metric_name: jvm.cpu.time