Resolve comments

Author: RichardChen820

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

@@ -126,17 +126,11 @@ public IEnumerable<ConfigurationClient> GetAvailableClients()
                 _ = DiscoverFallbackClients();
             }
 
-            List<ConfigurationClient> clients = new List<ConfigurationClient>(_clients.Where(c => c.BackoffEndTime <= now).Select(c => c.Client));
+            IEnumerable<ConfigurationClient> clients = _clients.Where(c => c.BackoffEndTime <= now).Select(c => c.Client);
 
-            if (_dynamicClients != null)
+            if (_dynamicClients != null && _dynamicClients.Any())
             {
-                foreach (ConfigurationClientWrapper client in _dynamicClients)
-                {
-                    if (client.BackoffEndTime <= now)
-                    {
-                        clients.Add(client.Client);
-                    }
-                }
+                clients = clients.Concat(_dynamicClients.Where(c => c.BackoffEndTime <= now).Select(c => c.Client));
             }
 
             return clients;
@@ -151,16 +145,13 @@ public IEnumerable<ConfigurationClient> GetAllClients()
                 _lastFallbackClientRefreshAttempt = now;
 
                 _ = DiscoverFallbackClients();
-            }
+            }
+
+            IEnumerable<ConfigurationClient> clients = _clients.Select(c => c.Client);
 
-            List<ConfigurationClient> clients = new List<ConfigurationClient>(_clients.Select(c => c.Client));
-
-            if (_dynamicClients != null)
+            if (_dynamicClients != null && _dynamicClients.Any())
             {
-                foreach (ConfigurationClientWrapper client in _dynamicClients)
-                {
-                    clients.Add(client.Client);
-                }
+                clients = clients.Concat(_dynamicClients.Select(c => c.Client));
             }
 
             return clients;
@@ -263,7 +254,7 @@ private async Task DiscoverFallbackClients()
             {
                 await RefreshFallbackClients(cts.Token).ConfigureAwait(false);
             }
-            catch (OperationCanceledException e)
+            catch (OperationCanceledException e) when (!_cancellationTokenSource.IsCancellationRequested)
             {
                 _logger.LogWarning(LogHelper.BuildFallbackClientLookupFailMessage(e.Message));
             }

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

@@ -48,19 +48,14 @@ public async Task<IEnumerable<SrvRecord>> QueryAsync(string host, CancellationTo
 
                 IEnumerable<SrvRecord> records = await InternalQueryAsync(altSrvDns, cancellationToken).ConfigureAwait(false);
 
-                if (records == null)
+                // If we get no record from _alt{i} SRV, we have reached the end of _alt* list
+                if (records == null || !records.Any())
                 {
                     break;
                 }
 
                 results = results.Concat(records);
 
-                // If we get no record from _alt{i} SRV, we have reached the end of _alt* list
-                if (records.Count() == 0)
-                {
-                    break;
-                }
-
                 index++;
             }