netty 5: reader stavation in nio & oio channel

[rzo12345]

hello,

on the same channel when there are continuous writes and some reads the read is never invoked, the only way to get a read invocation is to limit the write by adding Thread.sleep every x writes.

I did not have this issue with netty 3.

i tried setting the iorate to 99 but this did not help. i suppose its not an issue of the nio thread working on io/non-io tasks, but that for some reason data is not being read from the socket.

[rzo12345]

PS: forgot to mention that this is on the client side. That is, using Bootstrap. With ServerBootstrap all seems to work as expected.

[normanmaurer]

@rzo12345 could you share a reproducer or your code ?

[rzo12345]

hello,

to reproduce you can use the echo client/server example. change the client as follows:

    public void run() throws Exception {
        // Configure the client.
        EventLoopGroup group = new NioEventLoopGroup();
        try {
            Bootstrap b = new Bootstrap();
            b.group(group)
             .channel(NioSocketChannel.class)
             .option(ChannelOption.TCP_NODELAY, true)
             .handler(new ChannelInitializer<SocketChannel>() {
                 @Override
                 public void initChannel(SocketChannel ch) throws Exception {
                     ch.pipeline().addFirst(new LoggingHandler(LogLevel.INFO));
                     ch.pipeline().addLast(
                             new ChannelHandlerAdapter()
                             {
                                 @Override
                                    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception
                                    {

                                    }
                             });
                 }
             });

            // Start the client.
            ChannelFuture f = b.connect(host, port).sync();
            Channel c = f.channel();
            long l = 0;
            while (c.isActive())
            {
                c.write(c.alloc().buffer().writeLong(l++));
                c.flush();
            }

       } finally {
            // Shut down the event loop to terminate all threads.
            group.shutdownGracefully();
        }
    }

[rzo12345]

PS: as you may see the the server echoes the messages received and writes them back. but client side channelRead is never invoked.
if you add a sleep(100) into the while loop channelRead is invoked.

[rzo12345]

PS: i am testing on win XP. when the server is stopped, client side c.isActive() continues to return true.

[rzo12345]

PS: if a sleep() is added to the while loop the client recognizes the termination of the connection

[rzo12345]

hello, any progress on this issue ?

[johnou]

@rzo12345 do you experience the same issue with Netty 4.x?

[Scottmitch]

I will close this for now. 5.0 was abandoned a while ago. Please open another issue if this problem exists on 4.1.x.