private async Task RefreshFallbackClients()

in src/Microsoft.Extensions.Configuration.AzureAppConfiguration/ConfigurationClientManager.cs [246:303]
47 lines of code
11 McCabe index (conditional complexity)

        private async Task RefreshFallbackClients(CancellationToken cancellationToken)
        {
            IEnumerable<SrvRecord> srvTargetHosts = Enumerable.Empty<SrvRecord>();

            try
            {
                srvTargetHosts = await _srvLookupClient.QueryAsync(_endpoint.DnsSafeHost, cancellationToken).ConfigureAwait(false);
            }
            // Catch and log all exceptions thrown by srv lookup client to avoid new possible exceptions on app startup.
            catch (SocketException ex)
            {
                _logger.LogWarning(LogHelper.BuildFallbackClientLookupFailMessage(ex.Message));
                return;
            }
            catch (DnsResponseException ex)
            {
                _logger.LogWarning(LogHelper.BuildFallbackClientLookupFailMessage(ex.Message));
                return;
            }
            catch (InvalidOperationException ex)
            {
                _logger.LogWarning(LogHelper.BuildFallbackClientLookupFailMessage(ex.Message));
                return;
            }
            catch (DnsXidMismatchException ex)
            {
                _logger.LogWarning(LogHelper.BuildFallbackClientLookupFailMessage(ex.Message));
                return;
            }

            var newDynamicClients = new List<ConfigurationClientWrapper>();

            // Honor with the DNS based service discovery protocol, but shuffle the results first to ensure hosts can be picked randomly,
            // Srv lookup does retrieve trailing dot in the host name, just trim it.
            IEnumerable<string> OrderedHosts = srvTargetHosts.Any()
                ? srvTargetHosts.ToList().Shuffle().SortSrvRecords().Select(r => $"{r.Target.Value.TrimEnd('.')}")
                : Enumerable.Empty<string>();

            foreach (string host in OrderedHosts)
            {
                if (!string.IsNullOrEmpty(host) &&
                    !_clients.Any(c => c.Endpoint.Host.Equals(host, StringComparison.OrdinalIgnoreCase)) &&
                    IsValidEndpoint(host))
                {
                    var targetEndpoint = new Uri($"https://{host}");

                    var configClient = _credential == null
                        ? new ConfigurationClient(ConnectionStringUtils.Build(targetEndpoint, _id, _secret), _clientOptions)
                        : new ConfigurationClient(targetEndpoint, _credential, _clientOptions);

                    newDynamicClients.Add(new ConfigurationClientWrapper(targetEndpoint, configClient));
                }
            }

            _dynamicClients = newDynamicClients;

            _lastFallbackClientRefresh = DateTime.UtcNow;
        }