Why does ServerSocket stop working after some time?

Question

Hi to all.
I have a following problem:
I wrote a multithread application that uses sockets ( TCP ), and use it to transfer some objects between computers in VPN.
It all works just fine, except that sometimes my server socket ( implemented as a separate Thread ) just stops working, and other computers cannot connect to it...?
I didn't specify setSOTimeout(), and did all Exception catch-ing in the thread.
Today, I had some >50000 connections in about 5 hours, and than it just stopped! My server socket stopped accepting any connections...
I restarted my application, and everything worked again properly...
Does anybody know why is this happening?
Please, any suggestion is appreciated....
Thank you.

Answer 1

Hi, thank you all for answering me.
@baftos:
I didn't specify any backlog parameter value. 50 connections at a time seems more than enough for this application... ( Are you sure that 50 is the default value )
I never have more than about 40 connections simultaneously opened, and yes - each one is a separate thread.
@dannyyates:
You're rights, I should have provided some code.
Here it is:
public class Server implements Runnable
ServerSocket serversocket = null;
Socket clientSocket = null;
continueWorking boolean = true;
    public void run()
            startServer(); 
    public void startServer()
        try
             serversocket = new ServerSocket(3344);
        catch (IOException e)
             System.out.println(e.getMessage());  
     while ( continueWorking==true )
         try
              clientSocket = serversocket.accept();
              Worker Worker = new Worker(clientSocket);
              new Thread(Worker).start();
         catch (IOException e)
              System.out.println(e.getMessage());
        System.out.println("The server is shutting down...");
class Worker implements Runnable
    ObjectInputStream obj;
    Socket clientSocket;
    public Worker(Socket clientSocket)
         this.clientSocket = clientSocket;
        try
          obj = new ObjectInputStream(clientSocket.getInputStream());
         catch (IOException e)
              System.out.println(e.getMessage());
    public void run()
        Object object;
     try {
                      try
                           object=(Object)obj.readObject();
                                               // do something with object....
                      catch (ClassNotFoundException e)
                           System.out.println(e.getMessage());
                    catch (Exception e)
            obj.close();
            clientSocket.close();
     catch (IOException e)
    catch (Exception e)
    }What I don't like here is the constructor of the Worker. Could this block the server?
Edited by: Darko on Apr 7, 2009 11:24 PM