[Instrumentation.Process] Exposed required metric process.cpu.count for computing CPU utilization in the backend.

src/OpenTelemetry.Instrumentation.Process/ProcessMetrics.cs

@@ -16,6 +16,7 @@
 
 #nullable enable
 
+using System;
 using System.Collections.Generic;
 using System.Diagnostics.Metrics;
 using System.Reflection;
@@ -64,6 +65,15 @@ static ProcessMetrics()
             unit: "s",
             description: "Total CPU seconds broken down by different states.");
 
+        MeterInstance.CreateObservableUpDownCounter(
+            "process.processors",
+            () =>
+            {
+                return Environment.ProcessorCount;
+            },
+            unit: "{processors}",
+            description: "Process processors count.");
+
         MeterInstance.CreateObservableUpDownCounter(
             "process.threads",
             () =>

src/OpenTelemetry.Instrumentation.Process/README.md

@@ -92,6 +92,20 @@ Gets the user processor time for this process.
 * [Process.PrivilegedProcessorTime](https://learn.microsoft.com/dotnet/api/system.diagnostics.process.privilegedprocessortime):
 Gets the privileged processor time for this process.
 
+### process.processors
+
+Process threads count.
+
+| Units         | Instrument Type         | Value Type |
+|---------------|-------------------------|------------|
+| `{processors}`| ObservableUpDownCounter | `Int32`    |
+
+The API used to retrieve the value is:
+
+* [Process.processors](https://learn.microsoft.com/dotnet/api/system.environment.processorcount):
+Gets the number of processors available
+to the current process.
+
 ### process.threads
 
 Process threads count.

test/OpenTelemetry.Instrumentation.Process.Tests/ProcessMetricsTests.cs

@@ -38,13 +38,15 @@ public void ProcessMetricsAreCaptured()
 
         meterProviderA.ForceFlush(MaxTimeToAllowForFlush);
 
-        Assert.True(exportedItemsA.Count == 4);
+        Assert.True(exportedItemsA.Count == 5);
         var physicalMemoryMetric = exportedItemsA.FirstOrDefault(i => i.Name == "process.memory.usage");
         Assert.NotNull(physicalMemoryMetric);
         var virtualMemoryMetric = exportedItemsA.FirstOrDefault(i => i.Name == "process.memory.virtual");
         Assert.NotNull(virtualMemoryMetric);
         var cpuTimeMetric = exportedItemsA.FirstOrDefault(i => i.Name == "process.cpu.time");
         Assert.NotNull(cpuTimeMetric);
+        var processorCountMetric = exportedItemsA.FirstOrDefault(i => i.Name == "process.processors");
+        Assert.NotNull(processorCountMetric);
         var threadMetric = exportedItemsA.FirstOrDefault(i => i.Name == "process.threads");
         Assert.NotNull(threadMetric);
 
@@ -66,8 +68,8 @@ public void ProcessMetricsAreCaptured()
 
         meterProviderB.ForceFlush(MaxTimeToAllowForFlush);
 
-        Assert.True(exportedItemsA.Count == 4);
-        Assert.True(exportedItemsB.Count == 4);
+        Assert.True(exportedItemsA.Count == 5);
+        Assert.True(exportedItemsB.Count == 5);
     }
 
     [Fact]
@@ -142,23 +144,27 @@ public void ProcessMetricsAreCapturedWhenTasksOverlap()
 
         Task.WaitAll(tasks.ToArray());
 
-        Assert.True(exportedItemsA.Count == 4);
+        Assert.True(exportedItemsA.Count == 5);
         var physicalMemoryMetricA = exportedItemsA.FirstOrDefault(i => i.Name == "process.memory.usage");
         Assert.NotNull(physicalMemoryMetricA);
         var virtualMemoryMetricA = exportedItemsA.FirstOrDefault(i => i.Name == "process.memory.virtual");
         Assert.NotNull(virtualMemoryMetricA);
         var cpuTimeMetricA = exportedItemsA.FirstOrDefault(i => i.Name == "process.cpu.time");
         Assert.NotNull(cpuTimeMetricA);
+        var processorCountMetricA = exportedItemsA.FirstOrDefault(i => i.Name == "process.processors");
+        Assert.NotNull(processorCountMetricA);
         var threadMetricA = exportedItemsA.FirstOrDefault(i => i.Name == "process.threads");
         Assert.NotNull(threadMetricA);
 
-        Assert.True(exportedItemsB.Count == 4);
+        Assert.True(exportedItemsB.Count == 5);
         var physicalMemoryMetricB = exportedItemsB.FirstOrDefault(i => i.Name == "process.memory.usage");
         Assert.NotNull(physicalMemoryMetricB);
         var virtualMemoryMetricB = exportedItemsB.FirstOrDefault(i => i.Name == "process.memory.virtual");
         Assert.NotNull(virtualMemoryMetricB);
         var cpuTimeMetricB = exportedItemsB.FirstOrDefault(i => i.Name == "process.cpu.time");
         Assert.NotNull(cpuTimeMetricB);
+        var processorCountMetricB = exportedItemsB.FirstOrDefault(i => i.Name == "process.processors");
+        Assert.NotNull(processorCountMetricB);
         var threadMetricB = exportedItemsB.FirstOrDefault(i => i.Name == "process.threads");
         Assert.NotNull(threadMetricB);
     }