Scalability of socket server ssl server

Question

Hi

I developed secure socket server c# and using .net 3.5

I am using tclclient and tcl listener and using async functions to accept ,authenticate ,recieve and send operation.

The server just works fine for limited number of client connections .

troubles starts when client and server starts throwing exceptions especially in read and write call back IO exceptions ->inner exception is socket exception .

System.IO.IOException: Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host. ---> System.Net.Sockets.SocketException: An existing connection was forcibly closed by the remote host.

This error occurs if client connections exceeds around 300.

after sometime server stops accepting new connections , I see error as connection reset error on client side.

Not sure how to fix the issue .any ideas?

sample code is below

protected void StartReading()
{         
	try {                    
		state.buffer = this.SSLServer.BufferManager.CheckOut();
		if (state.workSslStream == ll)                    
		{
            Disconnect(); 
			return;                    
		}     
        IAsyncResult status = state.workSslStream.BeginRead(readBuffer, 0, readBuffer.Length, readCallback, state);                
		}
		catch (Exception ex)               
		{Disconnect();                
		}
		
} 
public void ReadCallback(IAsyncResult ar)        
{            
	int bytesRead = -1;            
	StateObject readState = (StateObject)ar.AsyncState;            
	try
	{                
		bytesRead = readState.workSslStream.EndRead(ar);                
		if (bytesRead != 0)                
		{                    
		   DataReceived(readBuffer, 0, bytesRead);                    
		   Thread.Sleep(1);                    if (!Doomed && readState.workSslStream != null) //we may have closed it during message processing                    
		   {                        
		   
		   if (readState.workSslStream == null )
		   {   
				Disconnect();
				return;                        
				
			}
			readState.workSslStream.BeginRead(readBuffer, 0, readBuffer.Length, readCallback, readState);                    
		} else 
		{        
			log.InfoFormat("in read call back zero bytes,{0}",IP);        
            Disconnect();  
			return;                
		}
	}catch (Exception ex) 
	{ 
		log.ErrorFormat("Error in Read call back: {0},{1}",IP, ex);                
		Disconnect();
		return;            
	}        
}
protected void AddToOutboundQueue(byte[] buffer)
        {
			lock (OutboundQueue)
			{
				OutboundQueue.Enqueue(buffer);
				if (!WriteInProgress)
				{
					 if(IsSSL)
					 {
						 SendSslOutboundPacket();
					 }
				}
			}
       }

        public void SendSslOutboundPacket()
        {
            IAsyncResult status;
            lock (this)
                if (Doomed)
                {
                    log.DebugFormat("In SendSslOutboundPacket in doomed");
                    FinalDisconnect();
                    return;
                }
            
            lock (OutboundQueue)
            {
                while (OutboundQueue.Count > 0)
                {
                    //CurrentMessage = OutboundQueue.Dequeue();
                    //int bytes = CurrentMessage.Length;
                    log.DebugFormat("in SendSsl Values of doomed,{0},{1}", Doomed,IP); 
                    try
                    {
                        
                        CurrentMessage = OutboundQueue.Dequeue();
                        int bytes = CurrentMessage.Length;
                        status = state.workSslStream.BeginWrite(CurrentMessage, 0, CurrentMessage.Length,writeCallback, state);
                        WriteInProgress = true;
                        status.AsyncWaitHandle.WaitOne();
                        WriteInProgress = false;
                        Interlocked.Add(ref bytesOut, bytes);
                        PerformanceCounters.BytesOut.IncrementBy(bytes);
                        status.AsyncWaitHandle.Close();
                        

                    }catch(Exception ex)
                    {
                        log.ErrorFormat("In SendSslOutboundPacket:{0},{1}", IP, ex);
                        OutboundQueue.Clear();  
                        Disconnect();
                        return;
                    }
                    Thread.Sleep(1);
                }
           }
          
        }
       
        public void WriteCallback(IAsyncResult ar)
        {
            StateObject writeState = (StateObject)ar.AsyncState;
            log.DebugFormat("in callback Values of doomed,{0}", Doomed); 
            try
            {
                lock (this)
                    if (Doomed)
                    {
                        log.DebugFormat("In write call back in doomed");
                        FinalDisconnect();
                        return;
                    }
                writeState.workSslStream.EndWrite(ar);
                writeState.workSslStream.Flush();
            }
            catch (Exception ex)
            {

                log.ErrorFormat("Error in WriteCallback ;{0},{1}", IP, ex);
                OutboundQueue.Clear();  
                Disconnect();
                return;
            }
        }
		public void Disconnect()
        {
            lock (this)
            {
                Doomed = true;
                if (state != null)
                    {
                        try
                        {
                            if (state.workSslStream != null)
                            {
                                log.DebugFormat("ssl stream displose,{0},{1}", Doomed, IP);
                                state.workSslStream.Dispose();
                                state.workSslStream = null;
                            }
                        }
                        catch
                        {
                        }
                        
                       state = null;

                    }

            }
		}

Thanks

 

Answer 1

Noone answer this question for me.

Please help me out.

Thanks

Answer 2

any ideas what is wrong with the code?

And also I see private memory  keep on increasing when new clients connected /disconnected.

my guess is there is some memory leak, not sure where.

could anybody help me out trouble shooting it.