handle null status code (#36547)

Author: vishweshbankwar

sdk/monitor/Azure.Monitor.OpenTelemetry.Exporter/src/Internals/StandardMetricsExtractionProcessor.cs

@@ -75,7 +75,7 @@ private void ReportRequestDurationMetric(Activity activity, string statusCodeAtt
             }
 
             TagList tags = default;
-            tags.Add(new KeyValuePair<string, object?>(StandardMetricConstants.RequestResultCodeKey, statusCodeAttributeValue));
+            tags.Add(new KeyValuePair<string, object?>(StandardMetricConstants.RequestResultCodeKey, statusCodeAttributeValue ?? "0"));
             tags.Add(new KeyValuePair<string, object?>(StandardMetricConstants.MetricIdKey, StandardMetricConstants.RequestDurationMetricIdValue));
             tags.Add(new KeyValuePair<string, object?>(StandardMetricConstants.IsAutoCollectedKey, "True"));
             tags.Add(new KeyValuePair<string, object?>(StandardMetricConstants.CloudRoleInstanceKey, StandardMetricResource?.RoleInstance));
@@ -92,13 +92,13 @@ private void ReportDependencyDurationMetric(Activity activity)
 
             var dependencyTarget = activityTagsProcessor.MappedTags.GetDependencyTarget(activityTagsProcessor.activityType);
 
-            var statusCode = AzMonList.GetTagValue(ref activityTagsProcessor.MappedTags, SemanticConventions.AttributeHttpStatusCode);
+            var statusCode = AzMonList.GetTagValue(ref activityTagsProcessor.MappedTags, SemanticConventions.AttributeHttpStatusCode)?.ToString();
 
             var dependencyType = activityTagsProcessor.MappedTags.GetDependencyType(activityTagsProcessor.activityType);
 
             TagList tags = default;
             tags.Add(new KeyValuePair<string, object?>(StandardMetricConstants.DependencyTargetKey, dependencyTarget));
-            tags.Add(new KeyValuePair<string, object?>(StandardMetricConstants.DependencyResultCodeKey, statusCode));
+            tags.Add(new KeyValuePair<string, object?>(StandardMetricConstants.DependencyResultCodeKey, statusCode ?? "0"));
             tags.Add(new KeyValuePair<string, object?>(StandardMetricConstants.MetricIdKey, StandardMetricConstants.DependencyDurationMetricIdValue));
             tags.Add(new KeyValuePair<string, object?>(StandardMetricConstants.IsAutoCollectedKey, "True"));
             tags.Add(new KeyValuePair<string, object?>(StandardMetricConstants.CloudRoleInstanceKey, StandardMetricResource?.RoleInstance));

sdk/monitor/Azure.Monitor.OpenTelemetry.Exporter/tests/Azure.Monitor.OpenTelemetry.Exporter.Tests/StandardMetricTests.cs

@@ -50,7 +50,6 @@ public void ValidateRequestDurationMetric()
 
             standardMetricCustomProcessor._meterProvider?.ForceFlush();
 
-            // Standard Metrics + Resource Metrics.
             Assert.Single(metricTelemetryItems);
 
             var metricTelemetry = metricTelemetryItems.Last()!;
@@ -102,7 +101,6 @@ public void ValidateDependencyDurationMetric()
 
             standardMetricCustomProcessor._meterProvider?.ForceFlush();
 
-            // Standard Metrics + Resource Metrics.
             Assert.Single(metricTelemetryItems);
 
             var metricTelemetry = metricTelemetryItems.Last()!;
@@ -125,6 +123,54 @@ public void ValidateDependencyDurationMetric()
             Assert.Equal("www.foo.com", dependencyTarget);
         }
 
+        [Theory]
+        [InlineData(ActivityKind.Server)]
+        [InlineData(ActivityKind.Client)]
+        public void ValidateNullStatusCode(ActivityKind kind)
+        {
+            var activitySource = new ActivitySource(nameof(StandardMetricTests.ValidateNullStatusCode));
+            var traceTelemetryItems = new List<TelemetryItem>();
+            var metricTelemetryItems = new List<TelemetryItem>();
+
+            var standardMetricCustomProcessor = new StandardMetricsExtractionProcessor(new AzureMonitorMetricExporter(new MockTransmitter(metricTelemetryItems)));
+
+            using var tracerProvider = Sdk.CreateTracerProviderBuilder()
+                .SetSampler(new AlwaysOnSampler())
+                .AddSource(nameof(StandardMetricTests.ValidateNullStatusCode))
+                .AddProcessor(standardMetricCustomProcessor)
+                .AddProcessor(new BatchActivityExportProcessor(new AzureMonitorTraceExporter(new MockTransmitter(traceTelemetryItems))))
+                .Build();
+
+            using (var activity = activitySource.StartActivity("Test", kind))
+            {
+                activity?.SetTag(SemanticConventions.AttributeHttpMethod, "Get");
+                activity?.SetTag(SemanticConventions.AttributeHttpUrl, "https://www.foo.com");
+            }
+
+            tracerProvider?.ForceFlush();
+
+            WaitForActivityExport(traceTelemetryItems);
+
+            standardMetricCustomProcessor._meterProvider?.ForceFlush();
+
+            // Standard Metrics + Resource Metrics.
+            Assert.Single(metricTelemetryItems);
+            var metricTelemetry = metricTelemetryItems.Last()!;
+            Assert.Equal("MetricData", metricTelemetry.Data.BaseType);
+            var metricData = (MetricsData)metricTelemetry.Data.BaseData;
+
+            if (kind == ActivityKind.Client)
+            {
+                Assert.True(metricData.Properties.TryGetValue(StandardMetricConstants.DependencyResultCodeKey, out var resultCode));
+                Assert.Equal("0", resultCode);
+            }
+            else
+            {
+                Assert.True(metricData.Properties.TryGetValue(StandardMetricConstants.RequestResultCodeKey, out var resultCode));
+                Assert.Equal("0", resultCode);
+            }
+        }
+
         private void WaitForActivityExport(List<TelemetryItem> traceTelemetryItems)
         {
             var result = SpinWait.SpinUntil(