Apache Mina Server Restart java.net.BindException: Address already in use

Question

I have a rather annoying problem in my server application.

I bind Apache Mina with the following code:

acceptor.bind(new InetSocketAddress(PORT));

Where acceptor is an NioSocketAcceptor. Over a HTTP interface I can shutdown the server so I can restart it.

Server.ioAcceptor.unbind(new InetSocketAddress(Server.PORT));
        for(IoSession session: Server.ioAcceptor.getManagedSessions().values()){
            if(session.isConnected() && !session.isClosing()){
                session.close(false);
            }
        }
        Server.ioAcceptor.dispose();

        Main.transport.stop();
        Logger.getRootLogger().warn("System going down. Request from "+context.getRemoteAddress());
        System.exit(10);       

This is the code I use to stop the Mina server. However if I try to start the server again in the next couple of minutes. (Somewhere between 5 minutes and 15 minutes) I get the following exception on start up: java.net.BindException: Address already in use

I also tried a simple ioAcceptor.unbind() but there was no difference. The server runs on Centos 5 with OpenJDK. Apache Mina version is 2.0 RC1.

Thank you in advance for any ideas on how to resolve this.

Answer 1

I'm not sure of the root cause, but I read somewhere a fix for this that seems to work for me:

acceptor.setReuseAddress(true);

Simply adding that let me shutdown and restart

Answer 2

A couple things I would add:

1. Set your acceptor to reuse the bound address

   acceptor.setReuseAddress(true)

2. In your close block, instead of

   session.close(false)

   use

   session.close(true)

   This will close the session immediately instead of waiting for a flush.

References:

Session close - http://mina.apache.org/report/trunk/apidocs/org/apache/mina/core/session/IoSession.html#close(boolean)

ServerSocket reuse address - http://download.oracle.com/javase/1.5.0/docs/api/java/net/ServerSocket.html?is-external=true#setReuseAddress(boolean)