How to debug ghost sessions

[白玉雄]

Hi all,
My mina server neither process session request nor disconnect the session as 
idle. and this happens only on few of sessions, most of them works well.


Some Code:
public void run(int port) throws IOException {
                this.acceptor = new NioSocketAcceptor();
                this.acceptor.setReuseAddress(true);


                this.acceptor.getFilterChain().addLast("codec",new 
ProtocolCodecFilter(new ClwMessageProtocolCodecFactory()));


                this.acceptor.getFilterChain().addLast("logger", new 
LoggingFilter());
                this.acceptor.getFilterChain().addLast("threadPool", new 
ExecutorFilter(new 
UnorderedThreadPoolExecutor(PropertiesHander.getInt("MAXIMUM_POOL_SIZE", 16))));


                this.acceptor.getSessionConfig().setReadBufferSize(512);
                this.acceptor.getSessionConfig().setReceiveBufferSize(512);
                // set idle time, default 900 seconds
                
this.acceptor.getSessionConfig().setIdleTime(IdleStatus.BOTH_IDLE,PropertiesHander.getInt("SESSION_IDLE_TIME",900));
                this.acceptor.setHandler(ioHandler);
                this.acceptor.bind(new InetSocketAddress(port));
                LOGGER.info("Socket server Listening on port "+ 
PropertiesHander.getInt("SERVER_PORT", port));
        }



Some phenomenons:
1、The ghost session can be found by 
this.acceptor.getManagedSessions().get(sessionId)
2、If force the client disconnect from server and reconnect again, the client 
now works well and request was processed normally.

It seems that the session was stucked.


Question:
Why this happens and How to reappear and debug this?


Thanks