MSDN Using Asynchronous Server Socket ?

microsoft.public.dotnet.framework

1 Feb 2006 2:41 PM

Zeeshan Gulzar

I am using the code of "MSDN-Using Asynchronous Server Socket". "ms-help://MS.VSCC.2003/MS.MSDNQTR.2004JUL.1033/cpguide/html/cpconnon-blockingserversocketexample.htm"

Here

        try {
            listener.Bind(localEndPoint);
            listener.Listen(100);

            while (true) {
                // Set the event to nonsignaled state.
                allDone.Reset();

                // Start an asynchronous socket to listen for connections.
                Console.WriteLine("Waiting for a connection...");
                listener.BeginAccept( new
AsyncCallback(AcceptCallback),listener );
                // Wait until a connection is made before continuing.
                allDone.WaitOne();
            }

Why we use

ManualResetEvent allDone = new ManualResetEvent(false);

and call allDone.Reset() every time.

and why not we use AutoResetEvent instead of ManualResetEvent. So not call
Reset method every time.

Any Reason ?.

Because when i use this code in my real application as a window service,
after some time (1 day or more) it reject to accept new sockets but service
still running. This service installed on 20 machines which is connected via
modem. But the problem occured on one or two machines.

Error : No connection could be made because the target computer actively
refused it
Code : 10061 WSAECONNREFUSED
Please help me urgently.
Zeeshan Gulzar

1 Feb 2006 3:29 PM

# Cyrille37 #

Zeeshan Gulzar wrote:
Show quote

> I am using the code of "MSDN-Using Asynchronous Server Socket".
> "ms-help://MS.VSCC.2003/MS.MSDNQTR.2004JUL.1033/cpguide/html/cpconnon-blockingserversocketexample.htm"
>
> Here
>
>         try {
>             listener.Bind(localEndPoint);
>             listener.Listen(100);
>
>             while (true) {
>                 // Set the event to nonsignaled state.
>                 allDone.Reset();
>
>                 // Start an asynchronous socket to listen for connections.
>                 Console.WriteLine("Waiting for a connection...");
>                 listener.BeginAccept( new
> AsyncCallback(AcceptCallback),listener );
>                 // Wait until a connection is made before continuing.
>                 allDone.WaitOne();
>             }
>
> Why we use
>
> ManualResetEvent allDone = new ManualResetEvent(false);
>
> and call allDone.Reset() every time.
>
> and why not we use AutoResetEvent instead of ManualResetEvent. So not call
> Reset method every time.
>
> Any Reason ?.
>
> Because when i use this code in my real application as a window service,
> after some time (1 day or more) it reject to accept new sockets but service
> still running. This service installed on 20 machines which is connected via
> modem. But the problem occured on one or two machines.
>
> Error : No connection could be made because the target computer actively
> refused it
> Code : 10061 WSAECONNREFUSED
> Please help me urgently.
> Zeeshan Gulzar
>

Look about implementing a override method like :

public override object InitializeLifetimeService()
{
return null;
}

I've to use it for remoting for the same problem, perhaps you need something
like that in you listening code.

Sorry to be so evasive.

cyrille

1 Feb 2006 5:40 PM

Vadym Stetsyak

Hello, Zeeshan!

How many connections must the service accept?
Are you sure that there were no exceptions in AcceptCallback?

IIRC in that example in AcceptCallback the call to BeginReceive is made. Are there any exceptions in the BeginReceive delegate.

allDone.Set() is called after the read is completed, maybe service is hanging on ReceiveData thus introducing deadlock for the accept thread?

ZG> Here

ZG>         try {
ZG>             listener.Bind(localEndPoint);
ZG>             listener.Listen(100);

ZG>             while (true) {
ZG>                 // Set the event to nonsignaled state.
ZG>                 allDone.Reset();

ZG>                 // Start an asynchronous socket to listen for
ZG> connections.
ZG>                 Console.WriteLine("Waiting for a connection...");
ZG>                 listener.BeginAccept( new
ZG> AsyncCallback(AcceptCallback),listener );
ZG>                 // Wait until a connection is made before continuing.
ZG>                 allDone.WaitOne();
ZG>             }

ZG> Why we use

ZG> ManualResetEvent allDone = new ManualResetEvent(false);

ZG> and call allDone.Reset() every time.

ZG> and why not we use AutoResetEvent instead of ManualResetEvent. So not
ZG> call Reset method every time.

ZG> Any Reason ?.

ZG> Because when i use this code in my real application as a window
ZG> service, after some time (1 day or more) it reject to accept new
ZG> sockets but service still running. This service installed on 20
ZG> machines which is connected via modem. But the problem occured on one
ZG> or two machines.

--
Regards, Vadym Stetsyak
www: http://vadmyst.blogspot.com

2 Feb 2006 2:18 PM

Michael D. Ober

I had a similar problem. The solution I ended up with was to make my
clients smart enough to reconnect on connection failure and then implement a
connection timeout. Remember that in .NET, you apparently cannot use the
framework to create a single threaded IP server, so you must deal with
interthread critical sections as each IP connection gets it's own thread.
As for the questions about number of connections and Exceptions in the
AcceptCallback, my answer was "unknown - possibly multiple per employee in
the company" and "my AcceptCallback" call wasn't inside an exception handler
and the application would have crashed had there been any.

Here's my code:

'============================================
Option Compare Text
Option Strict On
Option Explicit On

Imports System.Net.Sockets
Imports System.Net
Imports System.Threading
Imports System.Text.ASCIIEncoding

Module IPMessageHandler
Private ClientConnected As New AutoResetEvent(False)

Public Sub CreateListener()
    Dim ServerAddress As IPAddress =
Dns.GetHostEntry(My.Computer.Name).AddressList(0)
    Dim LocalHost As New IPEndPoint(ServerAddress,
OSInterface.iniWrapper.ReadInt("Dialer", "Port", "Wakefield.ini"))
    Dim tcpServer As New TcpListener(LocalHost)
    tcpServer.Start()
    WriteLog("Ready for IP Connections")
    Do
      tcpServer.BeginAcceptSocket(AddressOf AcceptRequest, tcpServer)
      Debug.Print("Waiting for a connection")
      ClientConnected.WaitOne()
    Loop
End Sub

Private Sub AcceptRequest(ByVal ar As System.IAsyncResult)
    Dim sock As Socket = Nothing
    Dim ClientEndPoint As New IPEndPoint(0, 0)
    Dim ClientName As String = ""
    Dim MsgIn As String = ""
    Dim BytesIn(1024) As Byte
    Dim i As Integer

    Try
      Debug.Print("Incoming Connection")
      Dim Listener As TcpListener = CType(ar.AsyncState, TcpListener)
      sock = Listener.EndAcceptSocket(ar)
      ClientEndPoint = CType(sock.RemoteEndPoint, IPEndPoint)
      ClientName = ClientEndPoint.Address.ToString
      ClientName = Dns.GetHostEntry(ClientName).HostName
      ClientName &= ":" & ClientEndPoint.Port.ToString
      ClientConnected.Set()

      ' If the socket remains unused for 5 minutes, error out and release
server resources
      If Not ClientName.Contains("Lily_Tomlin") Then sock.ReceiveTimeout = 5
* 60 * 1000
      Do
        Dim BytesReceived As Integer = sock.Receive(BytesIn)
        Select Case BytesReceived
          Case 0
            Exit Do
         Case Else
            MsgIn &= ASCII.GetString(BytesIn, 0, BytesReceived)
            i = InStr(MsgIn, EOL)
            Do While i > 0
               Dim msg As String = Left$(MsgIn, i - 1)
               MsgIn = Mid$(MsgIn, i + 1)
               Dim msgOut As String = ProcessMessage(msg)
               If msgOut <> "" Then
                 Dim BytesOut() As Byte = ASCII.GetBytes(msgOut & EOL)
                 sock.Send(BytesOut)
               End If
               i = InStr(MsgIn, EOL)
            Loop
         End Select
      Loop

    Catch ex As Exception
        WriteLog(ex.Message)
    Finally
       sock.Shutdown(SocketShutdown.Both)
       sock.Close()
    End Try
End Sub

Private Function ProcessMessage(ByVal msg As String) As String
    Dim msgReturn As String = ""
    Return msgReturn
End Function

End Module
'====================================
Mike.

"Vadym Stetsyak" <vady***@ukr.net> wrote in message
news:%23hPfJa1JGHA.2900@TK2MSFTNGP14.phx.gbl...
> Hello, Zeeshan!
>
> How many connections must the service accept?
> Are you sure that there were no exceptions in AcceptCallback?
>
> IIRC in that example in AcceptCallback the call to BeginReceive is made.

Are there any exceptions in the BeginReceive delegate.

>
> allDone.Set() is called after the read is completed, maybe service is

hanging on ReceiveData thus introducing deadlock for the accept thread?
Show quote

>
> ZG> Here
>
> ZG>         try {
> ZG>             listener.Bind(localEndPoint);
> ZG>             listener.Listen(100);
>
> ZG>             while (true) {
> ZG>                 // Set the event to nonsignaled state.
> ZG>                 allDone.Reset();
>
> ZG>                 // Start an asynchronous socket to listen for
> ZG> connections.
> ZG>                 Console.WriteLine("Waiting for a connection...");
> ZG>                 listener.BeginAccept( new
> ZG> AsyncCallback(AcceptCallback),listener );
> ZG>                 // Wait until a connection is made before continuing.
> ZG>                 allDone.WaitOne();
> ZG>             }
>
> ZG> Why we use
>
> ZG> ManualResetEvent allDone = new ManualResetEvent(false);
>
> ZG> and call allDone.Reset() every time.
>
> ZG> and why not we use AutoResetEvent instead of ManualResetEvent. So not
> ZG> call Reset method every time.
>
> ZG> Any Reason ?.
>
> ZG> Because when i use this code in my real application as a window
> ZG> service, after some time (1 day or more) it reject to accept new
> ZG> sockets but service still running. This service installed on 20
> ZG> machines which is connected via modem. But the problem occured on one
> ZG> or two machines.
>
> --
> Regards, Vadym Stetsyak
> www: http://vadmyst.blogspot.com

9 Feb 2006 11:03 AM

Zeeshan Gulzar

I am using MSDN Sample Code of "Using Asynchronous Server Socket (C#)" in a
windows service running
under Local System Account named Listener Service.

Client Code is also Asynchronous(C#) and embed in Windows Service running
under Local System Account
named Dispatcher Service.

This service works as follows:

1. Get message from Message Queue (MSMQ)
2. Connect to server at port 4000 (This machine is connected with server
machine via Modem
Both Start "Routing and Remote Access Service" just before Listener &
Dispatcher Services starts).
3. Send Message to server and close the socket immediately (Not set Linger
option. default setting used)
4. When client connected with server, server get Socket from ENDAccept(),
store in State class etc.
(Complete code is from MSDN Sample Code mentioned above.)
5. Server Received the message and close the socket immediately (Default
Setting of socket is used).

Problem is here:

After about an hour, server reject to accept new sockets. Netstat -a -p tcp
shows the port 4000 is in
listening state. Client receive Error WSACONNREFUSED.

One thing is that according to MSDN, this problem (Client received
WSACONNREFUSED while server is listening)
occured due to queue of the server is full (backlog). I set backlog of the
socket with 10 using
"socket.listen(10);". But why queue is full, because i receive message from
socket and close it immediately
so this sould returned back to queue. I increase this value to 100 instead
of 10 but problem is still there.
I am using Windows Server 2000.

Is this is the problem of TIME_WAIT. There is no entry of TcpTimedWaitDelay
in my registry.
Accoring to MSDN, this entry exist at
HKEY_LOCAL_MACHINE\System\CurrectControlSet\services\Tcpip\Parameters
Please help me in this regard.

Or could i cope this problem by set linger option of socket to 10 sec or
less. Please help me in this regard also.

Thanks in advance.

Show quote

"Vadym Stetsyak" wrote:

> Hello, Zeeshan!
>
> How many connections must the service accept?
> Are you sure that there were no exceptions in AcceptCallback?
>
> IIRC in that example in AcceptCallback the call to BeginReceive is made. Are there any exceptions in the BeginReceive delegate.
>
> allDone.Set() is called after the read is completed, maybe service is hanging on ReceiveData thus introducing deadlock for the accept thread?
>
> ZG> Here
>
> ZG>         try {
> ZG>             listener.Bind(localEndPoint);
> ZG>             listener.Listen(100);
>
> ZG>             while (true) {
> ZG>                 // Set the event to nonsignaled state.
> ZG>                 allDone.Reset();
>
> ZG>                 // Start an asynchronous socket to listen for
> ZG> connections.
> ZG>                 Console.WriteLine("Waiting for a connection...");
> ZG>                 listener.BeginAccept( new
> ZG> AsyncCallback(AcceptCallback),listener );
> ZG>                 // Wait until a connection is made before continuing.
> ZG>                 allDone.WaitOne();
> ZG>             }
>
> ZG> Why we use
>
> ZG> ManualResetEvent allDone = new ManualResetEvent(false);
>
> ZG> and call allDone.Reset() every time.
>
> ZG> and why not we use AutoResetEvent instead of ManualResetEvent. So not
> ZG> call Reset method every time.
>
> ZG> Any Reason ?.
>
> ZG> Because when i use this code in my real application as a window
> ZG> service, after some time (1 day or more) it reject to accept new
> ZG> sockets but service still running. This service installed on 20
> ZG> machines which is connected via modem. But the problem occured on one
> ZG> or two machines.
>
> --
> Regards, Vadym Stetsyak
> www: http://vadmyst.blogspot

9 Feb 2006 2:11 PM

Michael D. Ober

The problem is in your server code that handles the active connection. The
framework doesn't handle a lot of "idle" connections very well. When your
client disconnects, do you shutdown and then close the client socket?

Mike Ober.

Show quote

"Zeeshan Gulzar" <ZeeshanGul***@discussions.microsoft.com> wrote in message
news:7E8E4EB8-3CB6-40E5-96FE-40B1F0081715@microsoft.com...
> I am using MSDN Sample Code of "Using Asynchronous Server Socket (C#)" in
a
> windows service running
> under Local System Account named Listener Service.
>
> Client Code is also Asynchronous(C#) and embed in Windows Service running
> under Local System Account
> named Dispatcher Service.
>
> This service works as follows:
>
> 1. Get message from Message Queue (MSMQ)
> 2. Connect to server at port 4000 (This machine is connected with server
> machine via Modem
> Both Start "Routing and Remote Access Service" just before Listener &
> Dispatcher Services starts).
> 3. Send Message to server and close the socket immediately (Not set Linger
> option. default setting used)
> 4. When client connected with server, server get Socket from ENDAccept(),
> store in State class etc.
> (Complete code is from MSDN Sample Code mentioned above.)
> 5. Server Received the message and close the socket immediately (Default
> Setting of socket is used).
>
> Problem is here:
>
> After about an hour, server reject to accept new sockets. Netstat -a -p
tcp
> shows the port 4000 is in
> listening state. Client receive Error WSACONNREFUSED.
>
> One thing is that according to MSDN, this problem (Client received
> WSACONNREFUSED while server is listening)
> occured due to queue of the server is full (backlog). I set backlog of the
> socket with 10 using
> "socket.listen(10);". But why queue is full, because i receive message
from
> socket and close it immediately
> so this sould returned back to queue. I increase this value to 100 instead
> of 10 but problem is still there.
> I am using Windows Server 2000.
>
> Is this is the problem of TIME_WAIT. There is no entry of
TcpTimedWaitDelay
> in my registry.
> Accoring to MSDN, this entry exist at
> HKEY_LOCAL_MACHINE\System\CurrectControlSet\services\Tcpip\Parameters
> Please help me in this regard.
>
> Or could i cope this problem by set linger option of socket to 10 sec or
> less. Please help me in this regard also.
>
> Thanks in advance.
>
>
> "Vadym Stetsyak" wrote:
>
> > Hello, Zeeshan!
> >
> > How many connections must the service accept?
> > Are you sure that there were no exceptions in AcceptCallback?
> >
> > IIRC in that example in AcceptCallback the call to BeginReceive is made.

Are there any exceptions in the BeginReceive delegate.

> >
> > allDone.Set() is called after the read is completed, maybe service is

hanging on ReceiveData thus introducing deadlock for the accept thread?
Show quote

> >
> > ZG> Here
> >
> > ZG>         try {
> > ZG>             listener.Bind(localEndPoint);
> > ZG>             listener.Listen(100);
> >
> > ZG>             while (true) {
> > ZG>                 // Set the event to nonsignaled state.
> > ZG>                 allDone.Reset();
> >
> > ZG>                 // Start an asynchronous socket to listen for
> > ZG> connections.
> > ZG>                 Console.WriteLine("Waiting for a connection...");
> > ZG>                 listener.BeginAccept( new
> > ZG> AsyncCallback(AcceptCallback),listener );
> > ZG>                 // Wait until a connection is made before
continuing.
> > ZG>                 allDone.WaitOne();
> > ZG>             }
> >
> > ZG> Why we use
> >
> > ZG> ManualResetEvent allDone = new ManualResetEvent(false);
> >
> > ZG> and call allDone.Reset() every time.
> >
> > ZG> and why not we use AutoResetEvent instead of ManualResetEvent. So
not
> > ZG> call Reset method every time.
> >
> > ZG> Any Reason ?.
> >
> > ZG> Because when i use this code in my real application as a window
> > ZG> service, after some time (1 day or more) it reject to accept new
> > ZG> sockets but service still running. This service installed on 20
> > ZG> machines which is connected via modem. But the problem occured on
one
> > ZG> or two machines.
> >
> > --
> > Regards, Vadym Stetsyak
> > www: http://vadmyst.blogspot
>

9 Feb 2006 5:44 PM

Zeeshan Gulzar

Micheal Thanks,
I properly shutdown the socket after receiving the message.
socket.Shutdown(ShutdownType.Both);
socket.Close();

Show quote

"Michael D. Ober" wrote:

>
> The problem is in your server code that handles the active connection. The
> framework doesn't handle a lot of "idle" connections very well. When your
> client disconnects, do you shutdown and then close the client socket?
>
> Mike Ober.
>
>
> "Zeeshan Gulzar" <ZeeshanGul***@discussions.microsoft.com> wrote in message
> news:7E8E4EB8-3CB6-40E5-96FE-40B1F0081715@microsoft.com...
> > I am using MSDN Sample Code of "Using Asynchronous Server Socket (C#)" in
> a
> > windows service running
> > under Local System Account named Listener Service.
> >
> > Client Code is also Asynchronous(C#) and embed in Windows Service running
> > under Local System Account
> > named Dispatcher Service.
> >
> > This service works as follows:
> >
> > 1. Get message from Message Queue (MSMQ)
> > 2. Connect to server at port 4000 (This machine is connected with server
> > machine via Modem
> >    Both Start "Routing and Remote Access Service" just before Listener &
> > Dispatcher Services starts).
> > 3. Send Message to server and close the socket immediately (Not set Linger
> > option. default setting used)
> > 4. When client connected with server, server get Socket from ENDAccept(),
> > store in State class etc.
> >    (Complete code is from MSDN Sample Code mentioned above.)
> > 5. Server Received the message and close the socket immediately (Default
> > Setting of socket is used).
> >
> > Problem is here:
> >
> > After about an hour, server reject to accept new sockets. Netstat -a -p
> tcp
> > shows the port 4000 is in
> > listening state. Client receive Error WSACONNREFUSED.
> >
> > One thing is that according to MSDN, this problem (Client received
> > WSACONNREFUSED while server is listening)
> > occured due to queue of the server is full (backlog). I set backlog of the
> > socket with 10 using
> > "socket.listen(10);". But why queue is full, because i receive message
> from
> > socket and close it immediately
> > so this sould returned back to queue. I increase this value to 100 instead
> > of 10 but problem is still there.
> > I am using Windows Server 2000.
> >
> > Is this is the problem of TIME_WAIT. There is no entry of
> TcpTimedWaitDelay
> > in my registry.
> > Accoring to MSDN, this entry exist at
> > HKEY_LOCAL_MACHINE\System\CurrectControlSet\services\Tcpip\Parameters
> > Please help me in this regard.
> >
> > Or could i cope this problem by set linger option of socket to 10 sec or
> > less. Please help me in this regard also.
> >
> > Thanks in advance.
> >
> >
> > "Vadym Stetsyak" wrote:
> >
> > > Hello, Zeeshan!
> > >
> > > How many connections must the service accept?
> > > Are you sure that there were no exceptions in AcceptCallback?
> > >
> > > IIRC in that example in AcceptCallback the call to BeginReceive is made.
> Are there any exceptions in the BeginReceive delegate.
> > >
> > > allDone.Set() is called after the read is completed, maybe service is
> hanging on ReceiveData thus introducing deadlock for the accept thread?
> > >
> > > ZG> Here
> > >
> > > ZG>         try {
> > > ZG>             listener.Bind(localEndPoint);
> > > ZG>             listener.Listen(100);
> > >
> > > ZG>             while (true) {
> > > ZG>                 // Set the event to nonsignaled state.
> > > ZG>                 allDone.Reset();
> > >
> > > ZG>                 // Start an asynchronous socket to listen for
> > > ZG> connections.
> > > ZG>                 Console.WriteLine("Waiting for a connection...");
> > > ZG>                 listener.BeginAccept( new
> > > ZG> AsyncCallback(AcceptCallback),listener );
> > > ZG>                 // Wait until a connection is made before
> continuing.
> > > ZG>                 allDone.WaitOne();
> > > ZG>             }
> > >
> > > ZG> Why we use
> > >
> > > ZG> ManualResetEvent allDone = new ManualResetEvent(false);
> > >
> > > ZG> and call allDone.Reset() every time.
> > >
> > > ZG> and why not we use AutoResetEvent instead of ManualResetEvent. So
> not
> > > ZG> call Reset method every time.
> > >
> > > ZG> Any Reason ?.
> > >
> > > ZG> Because when i use this code in my real application as a window
> > > ZG> service, after some time (1 day or more) it reject to accept new
> > > ZG> sockets but service still running. This service installed on 20
> > > ZG> machines which is connected via modem. But the problem occured on
> one
> > > ZG> or two machines.
> > >
> > > --
> > > Regards, Vadym Stetsyak
> > > www: http://vadmyst.blogspot
> >
>
>
>
>

10 Feb 2006 2:20 PM

Michael D. Ober

Can you post the code that handles the socket accept and then the client
connection? I just went through this exercise (ported a TCP Server from
VB6) and had to work around a bug in the framework dealing with multiple
sockets. The raw WINSOCK API in Windows doesn't have this problem, thus my
feeling that this is a bug in the framework.

Mike Ober.

Show quote

"Zeeshan Gulzar" <ZeeshanGul***@discussions.microsoft.com> wrote in message
news:2EB0D8FB-A99A-44EB-99F2-2AD34283123E@microsoft.com...
> Micheal Thanks,
> I properly shutdown the socket after receiving the message.
> socket.Shutdown(ShutdownType.Both);
> socket.Close();
>
>
> "Michael D. Ober" wrote:
>
> >
> > The problem is in your server code that handles the active connection.
The
> > framework doesn't handle a lot of "idle" connections very well. When
your
> > client disconnects, do you shutdown and then close the client socket?
> >
> > Mike Ober.
> >
> >
> > "Zeeshan Gulzar" <ZeeshanGul***@discussions.microsoft.com> wrote in
message
> > news:7E8E4EB8-3CB6-40E5-96FE-40B1F0081715@microsoft.com...
> > > I am using MSDN Sample Code of "Using Asynchronous Server Socket (C#)"
in
> > a
> > > windows service running
> > > under Local System Account named Listener Service.
> > >
> > > Client Code is also Asynchronous(C#) and embed in Windows Service
running
> > > under Local System Account
> > > named Dispatcher Service.
> > >
> > > This service works as follows:
> > >
> > > 1. Get message from Message Queue (MSMQ)
> > > 2. Connect to server at port 4000 (This machine is connected with
server
> > > machine via Modem
> > > Both Start "Routing and Remote Access Service" just before Listener
&
> > > Dispatcher Services starts).
> > > 3. Send Message to server and close the socket immediately (Not set
Linger
> > > option. default setting used)
> > > 4. When client connected with server, server get Socket from
ENDAccept(),
> > > store in State class etc.
> > > (Complete code is from MSDN Sample Code mentioned above.)
> > > 5. Server Received the message and close the socket immediately
(Default
> > > Setting of socket is used).
> > >
> > > Problem is here:
> > >
> > > After about an hour, server reject to accept new sockets.

Netstat -a -p
Show quote

> > tcp
> > > shows the port 4000 is in
> > > listening state. Client receive Error WSACONNREFUSED.
> > >
> > > One thing is that according to MSDN, this problem (Client received
> > > WSACONNREFUSED while server is listening)
> > > occured due to queue of the server is full (backlog). I set backlog of
the
> > > socket with 10 using
> > > "socket.listen(10);". But why queue is full, because i receive message
> > from
> > > socket and close it immediately
> > > so this sould returned back to queue. I increase this value to 100
instead
> > > of 10 but problem is still there.
> > > I am using Windows Server 2000.
> > >
> > > Is this is the problem of TIME_WAIT. There is no entry of
> > TcpTimedWaitDelay
> > > in my registry.
> > > Accoring to MSDN, this entry exist at
> > > HKEY_LOCAL_MACHINE\System\CurrectControlSet\services\Tcpip\Parameters
> > > Please help me in this regard.
> > >
> > > Or could i cope this problem by set linger option of socket to 10 sec
or
> > > less. Please help me in this regard also.
> > >
> > > Thanks in advance.
> > >
> > >
> > > "Vadym Stetsyak" wrote:
> > >
> > > > Hello, Zeeshan!
> > > >
> > > > How many connections must the service accept?
> > > > Are you sure that there were no exceptions in AcceptCallback?
> > > >
> > > > IIRC in that example in AcceptCallback the call to BeginReceive is
made.
> > Are there any exceptions in the BeginReceive delegate.
> > > >
> > > > allDone.Set() is called after the read is completed, maybe service
is
> > hanging on ReceiveData thus introducing deadlock for the accept thread?
> > > >
> > > > ZG> Here
> > > >
> > > > ZG>         try {
> > > > ZG>             listener.Bind(localEndPoint);
> > > > ZG>             listener.Listen(100);
> > > >
> > > > ZG>             while (true) {
> > > > ZG>                 // Set the event to nonsignaled state.
> > > > ZG>                 allDone.Reset();
> > > >
> > > > ZG>                 // Start an asynchronous socket to listen for
> > > > ZG> connections.
> > > > ZG>                 Console.WriteLine("Waiting for a
connection...");
> > > > ZG>                 listener.BeginAccept( new
> > > > ZG> AsyncCallback(AcceptCallback),listener );
> > > > ZG>                 // Wait until a connection is made before
> > continuing.
> > > > ZG>                 allDone.WaitOne();
> > > > ZG>             }
> > > >
> > > > ZG> Why we use
> > > >
> > > > ZG> ManualResetEvent allDone = new ManualResetEvent(false);
> > > >
> > > > ZG> and call allDone.Reset() every time.
> > > >
> > > > ZG> and why not we use AutoResetEvent instead of ManualResetEvent.
So
> > not
> > > > ZG> call Reset method every time.
> > > >
> > > > ZG> Any Reason ?.
> > > >
> > > > ZG> Because when i use this code in my real application as a window
> > > > ZG> service, after some time (1 day or more) it reject to accept
new
> > > > ZG> sockets but service still running. This service installed on 20
> > > > ZG> machines which is connected via modem. But the problem occured
on
> > one
> > > > ZG> or two machines.
> > > >
> > > > --
> > > > Regards, Vadym Stetsyak
> > > > www: http://vadmyst.blogspot
> > >
> >
> >
> >
> >
>

12 Feb 2006 2:44 PM

Zeeshan Gulzar

Michael Thanks for your reply.

I mentioned earlier that i am using msdn "using asynchronous server socket"
example code as it is in a class library which is called from windows
service. and "using asynchronous client socket" for client service.

Show quote

"Michael D. Ober" wrote:

>
> Can you post the code that handles the socket accept and then the client
> connection? I just went through this exercise (ported a TCP Server from
> VB6) and had to work around a bug in the framework dealing with multiple
> sockets. The raw WINSOCK API in Windows doesn't have this problem, thus my
> feeling that this is a bug in the framework.
>
> Mike Ober.
>
>
>
> "Zeeshan Gulzar" <ZeeshanGul***@discussions.microsoft.com> wrote in message
> news:2EB0D8FB-A99A-44EB-99F2-2AD34283123E@microsoft.com...
> > Micheal Thanks,
> > I properly shutdown the socket after receiving the message.
> > socket.Shutdown(ShutdownType.Both);
> > socket.Close();
> >
> >
> > "Michael D. Ober" wrote:
> >
> > >
> > > The problem is in your server code that handles the active connection.
> The
> > > framework doesn't handle a lot of "idle" connections very well. When
> your
> > > client disconnects, do you shutdown and then close the client socket?
> > >
> > > Mike Ober.
> > >
> > >
> > > "Zeeshan Gulzar" <ZeeshanGul***@discussions.microsoft.com> wrote in
> message
> > > news:7E8E4EB8-3CB6-40E5-96FE-40B1F0081715@microsoft.com...
> > > > I am using MSDN Sample Code of "Using Asynchronous Server Socket (C#)"
> in
> > > a
> > > > windows service running
> > > > under Local System Account named Listener Service.
> > > >
> > > > Client Code is also Asynchronous(C#) and embed in Windows Service
> running
> > > > under Local System Account
> > > > named Dispatcher Service.
> > > >
> > > > This service works as follows:
> > > >
> > > > 1. Get message from Message Queue (MSMQ)
> > > > 2. Connect to server at port 4000 (This machine is connected with
> server
> > > > machine via Modem
> > > >    Both Start "Routing and Remote Access Service" just before Listener
> &
> > > > Dispatcher Services starts).
> > > > 3. Send Message to server and close the socket immediately (Not set
> Linger
> > > > option. default setting used)
> > > > 4. When client connected with server, server get Socket from
> ENDAccept(),
> > > > store in State class etc.
> > > >    (Complete code is from MSDN Sample Code mentioned above.)
> > > > 5. Server Received the message and close the socket immediately
> (Default
> > > > Setting of socket is used).
> > > >
> > > > Problem is here:
> > > >
> > > > After about an hour, server reject to accept new sockets.
> Netstat -a -p
> > > tcp
> > > > shows the port 4000 is in
> > > > listening state. Client receive Error WSACONNREFUSED.
> > > >
> > > > One thing is that according to MSDN, this problem (Client received
> > > > WSACONNREFUSED while server is listening)
> > > > occured due to queue of the server is full (backlog). I set backlog of
> the
> > > > socket with 10 using
> > > > "socket.listen(10);". But why queue is full, because i receive message
> > > from
> > > > socket and close it immediately
> > > > so this sould returned back to queue. I increase this value to 100
> instead
> > > > of 10 but problem is still there.
> > > > I am using Windows Server 2000.
> > > >
> > > > Is this is the problem of TIME_WAIT. There is no entry of
> > > TcpTimedWaitDelay
> > > > in my registry.
> > > > Accoring to MSDN, this entry exist at
> > > > HKEY_LOCAL_MACHINE\System\CurrectControlSet\services\Tcpip\Parameters
> > > > Please help me in this regard.
> > > >
> > > > Or could i cope this problem by set linger option of socket to 10 sec
> or
> > > > less. Please help me in this regard also.
> > > >
> > > > Thanks in advance.
> > > >
> > > >
> > > > "Vadym Stetsyak" wrote:
> > > >
> > > > > Hello, Zeeshan!
> > > > >
> > > > > How many connections must the service accept?
> > > > > Are you sure that there were no exceptions in AcceptCallback?
> > > > >
> > > > > IIRC in that example in AcceptCallback the call to BeginReceive is
> made.
> > > Are there any exceptions in the BeginReceive delegate.
> > > > >
> > > > > allDone.Set() is called after the read is completed, maybe service
> is
> > > hanging on ReceiveData thus introducing deadlock for the accept thread?
> > > > >
> > > > > ZG> Here
> > > > >
> > > > > ZG>         try {
> > > > > ZG>             listener.Bind(localEndPoint);
> > > > > ZG>             listener.Listen(100);
> > > > >
> > > > > ZG>             while (true) {
> > > > > ZG>                 // Set the event to nonsignaled state.
> > > > > ZG>                 allDone.Reset();
> > > > >
> > > > > ZG>                 // Start an asynchronous socket to listen for
> > > > > ZG> connections.
> > > > > ZG>                 Console.WriteLine("Waiting for a
> connection...");
> > > > > ZG>                 listener.BeginAccept( new
> > > > > ZG> AsyncCallback(AcceptCallback),listener );
> > > > > ZG>                 // Wait until a connection is made before
> > > continuing.
> > > > > ZG>                 allDone.WaitOne();
> > > > > ZG>             }
> > > > >
> > > > > ZG> Why we use
> > > > >
> > > > > ZG> ManualResetEvent allDone = new ManualResetEvent(false);
> > > > >
> > > > > ZG> and call allDone.Reset() every time.
> > > > >
> > > > > ZG> and why not we use AutoResetEvent instead of ManualResetEvent.
> So
> > > not
> > > > > ZG> call Reset method every time.
> > > > >
> > > > > ZG> Any Reason ?.
> > > > >
> > > > > ZG> Because when i use this code in my real application as a window
> > > > > ZG> service, after some time (1 day or more) it reject to accept
> new
> > > > > ZG> sockets but service still running. This service installed on 20
> > > > > ZG> machines which is connected via modem. But the problem occured
> on
> > > one
> > > > > ZG> or two machines.
> > > > >
> > > > > --
> > > > > Regards, Vadym Stetsyak
> > > > > www: http://vadmyst.blogspot
> > > >
> > >
> > >
> > >
> > >
> >
>
>
>
>