// Error
SocketException: An operation on a socket could not be performed because the system lacked sufficient buffer space or because a queue was full

System.Net.Sockets.Socket.UpdateStatusAfterSocketErrorAndThrowException(SocketError error, string callerName)System.Net.Sockets.Socket.DoBind(EndPoint endPointSnapshot, SocketAddress socketAddress)System.Net.Sockets.Socket.InternalBind(EndPoint localEP)System.Net.Sockets.Socket.BeginConnectEx(EndPoint remoteEP, bool flowContext, AsyncCallback callback, object state)System.Net.Sockets.Socket.UnsafeBeginConnect(EndPoint remoteEP, AsyncCallback callback, object state, bool flowContext)System.Net.Sockets.Socket.BeginConnect(EndPoint remoteEP, AsyncCallback callback, object state)System.Net.Sockets.Socket.ConnectAsync(EndPoint remoteEP)MongoDB.Driver.Core.Connections.TcpStreamFactory.ConnectAsync(Socket socket, EndPoint endPoint, CancellationToken cancellationToken)MongoDB.Driver.Core.Connections.TcpStreamFactory.CreateStreamAsync(EndPoint endPoint, CancellationToken cancellationToken)MongoDB.Driver.Core.Connections.BinaryConnection.OpenHelperAsync(CancellationToken cancellationToken)

 MongoConnectionException: An exception occurred while opening a connection to the server.

MongoDB.Driver.Core.Connections.BinaryConnection.OpenHelperAsync(CancellationToken cancellationToken)
MongoDB.Driver.Core.Servers.Server.GetChannelAsync(CancellationToken cancellationToken)
MongoDB.Driver.Core.Operations.FindOperation<TDocument>.ExecuteAsync(IReadBinding binding, CancellationToken cancellationToken)
MongoDB.Driver.OperationExecutor.ExecuteReadOperationAsync<TResult>(IReadBinding binding, IReadOperation<TResult> operation, CancellationToken cancellationToken)
MongoDB.Driver.MongoCollectionImpl<TDocument>.ExecuteReadOperationAsync<TResult>(IClientSessionHandle session, IReadOperation<TResult> operation, ReadPreference readPreference, CancellationToken cancellationToken)
MongoDB.Driver.MongoCollectionImpl<TDocument>.UsingImplicitSessionAsync<TResult>(Func<IClientSessionHandle, Task<TResult>> funcAsync, CancellationToken cancellationToken)
MongoDB.Driver.IAsyncCursorSourceExtensions.FirstOrDefaultAsync<TDocument>(IAsyncCursorSource<TDocument> source, CancellationToken cancellationToken)

// code placeholder
var settings = MongoClientSettings.FromConnectionString(config.CacheConnection);void SocketConfigurator(Socket s) => s.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.KeepAlive, true);            settings.SocketTimeout = TimeSpan.FromMinutes(5);
settings.ConnectTimeout = TimeSpan.FromSeconds(60);
settings.MaxConnectionIdleTime = TimeSpan.FromSeconds(30);
settings.ClusterConfigurator = cb => cb.ConfigureTcp(tcp => tcp.With(socketConfigurator: (Action<Socket>)SocketConfigurator));            var mongoClient = new MongoClient(settings);            services.AddScoped<ICacheDatabase>(t => new CacheDatabase(config, mongoClient));

internal struct KeepAliveValues
        {
            public uint OnOff { get; set; }
            public uint KeepAliveTime { get; set; }
            public uint KeepAliveInterval { get; set; }

            public byte[] ToBytes()
            {
                var bytes = new byte[12];
                Array.Copy(BitConverter.GetBytes(OnOff), 0, bytes, 0, 4);
                Array.Copy(BitConverter.GetBytes(KeepAliveTime), 0, bytes, 4, 4);
                Array.Copy(BitConverter.GetBytes(KeepAliveInterval), 0, bytes, 8, 4);
                return bytes;
            }
        }

        internal static void SocketConfigurator(Socket s)
        {
            var keepAliveValues = new KeepAliveValues()
            {
                OnOff = 1,
                KeepAliveTime = 120 * 1000,   // 120 seconds in milliseconds
                KeepAliveInterval = 10 * 1000 // 10 seconds in milliseconds
            };

            s.IOControl(IOControlCode.KeepAliveValues, keepAliveValues.ToBytes(), null);
        }