Added Request tracing and case for snapshot reference is registered for refresh by not called in select

Author: t-vvidyasaga

src/Microsoft.Extensions.Configuration.AzureAppConfiguration/AzureAppConfigurationProvider.cs

@@ -630,6 +630,7 @@ private async Task<Dictionary<string, string>> PrepareData(Dictionary<string, Co
             if (_requestTracingEnabled && _requestTracingOptions != null)
             {
                 _requestTracingOptions.ResetAiConfigurationTracing();
+                _requestTracingOptions.ResetSnapshotReferenceTracing();
             }
 
             foreach (KeyValuePair<string, ConfigurationSetting> kvp in data)
@@ -877,6 +878,12 @@ await CallWithRequestTracing(async () =>
                             {
                                 if (setting.ContentType == SnapshotReferenceConstants.ContentType)
                                 {
+                                    // Track snapshot reference usage for telemetry
+                                    if (_requestTracingEnabled && _requestTracingOptions != null)
+                                    {
+                                        _requestTracingOptions.UpdateSnapshotReferenceTracing(setting.ContentType);
+                                    }
+
                                     var snapshotReference = new SnapshotReference { SnapshotName = SnapshotReferenceParser.Parse(setting) };
 
                                     Dictionary<string, ConfigurationSetting> resolvedSettings = await Resolve(snapshotReference, client, cancellationToken).ConfigureAwait(false);
@@ -945,11 +952,11 @@ private async Task<Dictionary<string, ConfigurationSetting>> Resolve(SnapshotRef
                 return resolvedSettings;
             }
 
-            ConfigurationSnapshot snapshot;
+            ConfigurationSnapshot snapshot = null;
 
             try
             {
-                snapshot = await client.GetSnapshotAsync(snapshotReference.SnapshotName, cancellationToken: cancellationToken).ConfigureAwait(false);
+                await CallWithRequestTracing(async () => snapshot = await client.GetSnapshotAsync(snapshotReference.SnapshotName, cancellationToken: cancellationToken).ConfigureAwait(false)).ConfigureAwait(false);
             }
             catch (RequestFailedException rfe) when (rfe.Status == (int)HttpStatusCode.NotFound)
             {
@@ -1013,8 +1020,31 @@ private async Task<Dictionary<KeyValueIdentifier, ConfigurationSetting>> LoadKey
                 // If the key-value was found, store it for updating the settings
                 if (watchedKv != null)
                 {
-                    watchedIndividualKvs[watchedKeyLabel] = new ConfigurationSetting(watchedKv.Key, watchedKv.Value, watchedKv.Label, watchedKv.ETag);
-                    existingSettings[watchedKey] = watchedKv;
+                    if (watchedKv.ContentType == SnapshotReferenceConstants.ContentType)
+                    {
+                        // Track snapshot reference usage for telemetry
+                        if (_requestTracingEnabled && _requestTracingOptions != null)
+                        {
+                            _requestTracingOptions.UpdateSnapshotReferenceTracing(watchedKv.ContentType);
+                        }
+
+                        var snapshotReference = new SnapshotReference { SnapshotName = SnapshotReferenceParser.Parse(watchedKv) };
+
+                        Dictionary<string, ConfigurationSetting> resolvedSettings = await Resolve(snapshotReference, client, cancellationToken).ConfigureAwait(false);
+
+                        foreach (KeyValuePair<string, ConfigurationSetting> resolvedSetting in resolvedSettings)
+                        {
+                            existingSettings[resolvedSetting.Key] = resolvedSetting.Value;
+                        }
+
+                        // Only track the snapshot reference itself for refresh monitoring, since snapshots are immutable
+                        watchedIndividualKvs[watchedKeyLabel] = new ConfigurationSetting(watchedKv.Key, watchedKv.Value, watchedKv.Label, watchedKv.ETag);
+                    }
+                    else
+                    {
+                        watchedIndividualKvs[watchedKeyLabel] = new ConfigurationSetting(watchedKv.Key, watchedKv.Value, watchedKv.Label, watchedKv.ETag);
+                        existingSettings[watchedKey] = watchedKv;
+                    }
                 }
             }
 

src/Microsoft.Extensions.Configuration.AzureAppConfiguration/Constants/RequestTracingConstants.cs

@@ -27,6 +27,8 @@ internal class RequestTracingConstants
         public const string DevEnvironmentValue = "Dev";
         public const string KeyVaultConfiguredTag = "UsesKeyVault";
         public const string KeyVaultRefreshConfiguredTag = "RefreshesKeyVault";
+        public const string SnapshotReferenceTag = "UsesSnapshotRef";
+        public const string SnapshotReferenceCountKey = "SnapRefCount";
         public const string ReplicaCountKey = "ReplicaCount";
         public const string FeaturesKey = "Features";
         public const string LoadBalancingEnabledTag = "LB";

src/Microsoft.Extensions.Configuration.AzureAppConfiguration/RequestTracingOptions.cs

@@ -82,6 +82,16 @@ internal class RequestTracingOptions
         /// </summary>
         public bool UsesAIChatCompletionConfiguration { get; set; } = false;
 
+        /// <summary>
+        /// Flag to indicate whether any key-value uses snapshot references.
+        /// </summary>
+        public bool UsesSnapshotReferences { get; set; } = false;
+
+        /// <summary>
+        /// Count of snapshot references that have been resolved during configuration loading.
+        /// </summary>
+        public int SnapshotReferenceCount { get; set; } = 0;
+
         /// <summary>
         /// Resets the AI configuration tracing flags.
         /// </summary>
@@ -91,6 +101,15 @@ public void ResetAiConfigurationTracing()
             UsesAIChatCompletionConfiguration = false;
         }
 
+        /// <summary>
+        /// Resets the snapshot reference tracing counters and flags.
+        /// </summary>
+        public void ResetSnapshotReferenceTracing()
+        {
+            UsesSnapshotReferences = false;
+            SnapshotReferenceCount = 0;
+        }
+
         /// <summary>
         /// Updates AI configuration tracing flags based on the provided content type.
         /// </summary>
@@ -111,6 +130,21 @@ public void UpdateAiConfigurationTracing(string contentTypeString)
             }
         }
 
+        /// <summary>
+        /// Updates snapshot reference tracing when a snapshot reference is encountered.
+        /// </summary>
+        /// <param name="contentTypeString">The content type to analyze.</param>
+        public void UpdateSnapshotReferenceTracing(string contentTypeString)
+        {
+            if (!string.IsNullOrWhiteSpace(contentTypeString) &&
+                contentTypeString.TryParseContentType(out ContentType contentType) &&
+                contentType.IsSnapshotReference())
+            {
+                UsesSnapshotReferences = true;
+                SnapshotReferenceCount++;
+            }
+        }
+
         /// <summary>
         /// Checks whether any tracing feature is used.
         /// </summary>
@@ -120,7 +154,8 @@ public bool UsesAnyTracingFeature()
             return IsLoadBalancingEnabled ||
                 IsSignalRUsed ||
                 UsesAIConfiguration ||
-                UsesAIChatCompletionConfiguration;
+                UsesAIChatCompletionConfiguration ||
+                UsesSnapshotReferences;
         }
 
         /// <summary>
@@ -171,6 +206,16 @@ public string CreateFeaturesString()
                 sb.Append(RequestTracingConstants.AIChatCompletionConfigurationTag);
             }
 
+            if (UsesSnapshotReferences)
+            {
+                if (sb.Length > 0)
+                {
+                    sb.Append(RequestTracingConstants.Delimiter);
+                }
+
+                sb.Append(RequestTracingConstants.SnapshotReferenceTag);
+            }
+
             return sb.ToString();
         }
     }

src/Microsoft.Extensions.Configuration.AzureAppConfiguration/TracingUtils.cs

@@ -196,6 +196,16 @@ private static string CreateCorrelationContextHeader(RequestType requestType, Re
                 correlationContextTags.Add(RequestTracingConstants.KeyVaultRefreshConfiguredTag);
             }
 
+            if (requestTracingOptions.UsesSnapshotReferences)
+            {
+                correlationContextTags.Add(RequestTracingConstants.SnapshotReferenceTag);
+            }
+
+            if (requestTracingOptions.SnapshotReferenceCount > 0)
+            {
+                correlationContextKeyValues.Add(new KeyValuePair<string, string>(RequestTracingConstants.SnapshotReferenceCountKey, requestTracingOptions.SnapshotReferenceCount.ToString()));
+            }
+
             if (requestTracingOptions.IsFailoverRequest)
             {
                 correlationContextTags.Add(RequestTracingConstants.FailoverRequestTag);