Java Netty负载测试问题

Question

我编写了使用文本协议接受连接和轰炸消息（〜100字节）的服务器，并且我的实现能够与3rt客户端发送约400K /
sec的回送消息。我为此任务选择了Netty，即SUSE 11 RealTime，JRockit
RTS。但是，当我开始基于Netty开发自己的客户端时，吞吐量却急剧下降（从400K msg / sec降低到1.3K msg /
sec）。客户端的代码非常简单。能否请您提供建议或示例，说明如何编写更有效的客户。实际上，我实际上更关心延迟，但是从吞吐量测试开始，我认为在环回中以1.5Kmsg
/ sec的速度正常是不正常的。PS客户端的目的只是接收来自服务器的消息，很少发送心跳信号。

Client.java

public class Client {

private static ClientBootstrap bootstrap;
private static Channel connector;
public static boolean start()
{
    ChannelFactory factory =
        new NioClientSocketChannelFactory(
                Executors.newCachedThreadPool(),
                Executors.newCachedThreadPool());
    ExecutionHandler executionHandler = new ExecutionHandler( new OrderedMemoryAwareThreadPoolExecutor(16, 1048576, 1048576));

    bootstrap = new ClientBootstrap(factory);

    bootstrap.setPipelineFactory( new ClientPipelineFactory() );

    bootstrap.setOption("tcpNoDelay", true);
    bootstrap.setOption("keepAlive", true);
    bootstrap.setOption("receiveBufferSize", 1048576);
    ChannelFuture future = bootstrap
            .connect(new InetSocketAddress("localhost", 9013));
    if (!future.awaitUninterruptibly().isSuccess()) {
        System.out.println("--- CLIENT - Failed to connect to server at " +
                           "localhost:9013.");
        bootstrap.releaseExternalResources();
        return false;
    }

    connector = future.getChannel();

    return connector.isConnected();
}
public static void main( String[] args )
{
    boolean started = start();
    if ( started )
        System.out.println( "Client connected to the server" );
}

}

ClientPipelineFactory.java

public class ClientPipelineFactory  implements ChannelPipelineFactory{

private final ExecutionHandler executionHandler;
public ClientPipelineFactory( ExecutionHandler executionHandle )
{
    this.executionHandler = executionHandle;
}
@Override
public ChannelPipeline getPipeline() throws Exception {
    ChannelPipeline pipeline = pipeline();
    pipeline.addLast("framer", new DelimiterBasedFrameDecoder(
              1024, Delimiters.lineDelimiter()));
    pipeline.addLast( "executor", executionHandler);
    pipeline.addLast("handler", new MessageHandler() );

    return pipeline;
}

}

MessageHandler.java
public class MessageHandler extends SimpleChannelHandler{

long max_msg = 10000;
long cur_msg = 0;
long startTime = System.nanoTime();
@Override
public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) {
    cur_msg++;

    if ( cur_msg == max_msg )
    {
        System.out.println( "Throughput (msg/sec) : " + max_msg* NANOS_IN_SEC/(     System.nanoTime() - startTime )   );
        cur_msg = 0;
        startTime = System.nanoTime();
    }
}

@Override
public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) {
    e.getCause().printStackTrace();
    e.getChannel().close();
}

}

更新。在服务器端，存在一个定期线程，该线程写入已接受的客户端通道。而且该频道很快就无法写入。更新N2。在管道中添加了OrderedMemoryAwareExecutor，但是吞吐量仍然很低（大约4k
msg / sec）

固定。我将执行程序放在整个管道堆栈的前面，结果成功了！

Answer 1

如果服务器正在发送固定大小（〜100字节）的消息，则可以将ReceiveBufferSizePredictor设置为客户端引导程序，这将优化读取

bootstrap.setOption("receiveBufferSizePredictorFactory",
            new AdaptiveReceiveBufferSizePredictorFactory(MIN_PACKET_SIZE, INITIAL_PACKET_SIZE, MAX_PACKET_SIZE));

根据您发布的代码段：客户端的nio工作线程正在做管道中的所有事情，因此它将忙于解码和执行消息处理程序。您必须添加一个执行处理程序。

您已经说过，通道从服务器端变得不可写，因此您可能必须在服务器引导程序中调整水印大小。您可以定期监视写缓冲区大小（写队列大小），并确保由于消息无法写到网络而使通道变得不可写。可以通过以下类似的util类来完成。

package org.jboss.netty.channel.socket.nio;

import org.jboss.netty.channel.Channel;

public final class NioChannelUtil {
  public static long getWriteTaskQueueCount(Channel channel) {
    NioSocketChannel nioChannel = (NioSocketChannel) channel;
    return nioChannel.writeBufferSize.get();
  }
}