Netty高性能大容量Socket并发（一）：Netty性能测试

Netty性能测试

Netty是由JBOSS提供的一个java开源框架。Netty提供异步的、事件驱动的网络应用程序框架和工具，用以快速开发高性能、高可靠性的网络服务器和客户端程序。Netty 是一个基于NIO的客户，服务器端编程框架，使用Netty 可以确保你快速和简单的开发出一个网络应用，例如实现了某种协议的客户，服务端应用。Netty相当简化和流线化了网络应用的编程开发过程，例如，TCP和UDP的socket服务开发。

Netty简化socket编程，并没有使写出来的Socket效率变低，我写了一个所有都使用默认配置的服务端，模拟最常用的RPC方案，传输协议使用4字节长度加json串的方式来传输，测试服务端的通讯效率，测试结果如下。

从测试结果看，Netty性能是非常高的，在所有使用默认配置的情况下，单台服务器能够达到4万次请求解析，作为RPC框架是足够用的。还有一个有趣的现象是每次都创建连接和重用连接的差别不大，性能损耗对应用层几乎没影响，但是大家如果在应用环境中使用每次新建的情况，一定要进行压测，确认没影响后再使用。

测试用例说明

1. 部署1台Netty服务器，部署8台并发测试客户端，每个客户端跑1024个并发；
2. 分为1次连接请求1000次数据和1次连接请求1次数据循环1000次；
3. Netty服务器为Cent OS 6.5 64位，阿里云8核16G内存，JVM使用默认配置，没有进行任何调优；
4. 并发客户端为Windows Server 2008 R2  64位企业版，阿里云8核16G内存，NET Framework 4.5运行环境，没有进行任何调优；
5. 通讯数据格式为：4字节长度+JSON串，服务器负责接收JSON串，进行解析和返回；

Netty服务端代码

主程序入口

public class AppNettyServer {

    public static void main(String[] args) throws Exception {
        System.out.print("Hello Netty\r\n");

        int port = 9090;
        if (args != null && args.length > 0) {
            try {
                port = Integer.valueOf(args[0]);
            } catch (NumberFormatException e) {
                System.out.print("Invalid Port, Start Default Port: 9090");
            }
        }
        try {
            NettyCommandServer commandServer = new NettyCommandServer();
            System.out.print("Start listen socket, port " + port + "\r\n");
            commandServer.bind(port);
        } catch (Exception e) {
            System.out.print(e.getMessage());
        }
    }
}

Netty服务端初始化

public class NettyCommandServer {

    public static InternalLogger logger = InternalLoggerFactory.getInstance(NettyCommandServer.class);

    public void bind(int port) throws Exception {
        EventLoopGroup bossGroup = new NioEventLoopGroup();
        EventLoopGroup workerGroup = new NioEventLoopGroup();
        try {
            ServerBootstrap serverBootstrap = new ServerBootstrap();
            serverBootstrap.group(bossGroup, workerGroup);
            serverBootstrap.channel(NioServerSocketChannel.class);
            serverBootstrap.option(ChannelOption.SO_BACKLOG, 1024);
            serverBootstrap.handler(new LoggingHandler());
            serverBootstrap.childHandler(new NettyChannelHandler());
            ChannelFuture channelFuture = serverBootstrap.bind(port).sync();
            channelFuture.channel().closeFuture().sync();
        } finally {
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }
    }

    private class NettyChannelHandler extends ChannelInitializer {

        @Override
        protected void initChannel(SocketChannel socketChannel)
                throws Exception {
            socketChannel.pipeline().addLast(new LengthFieldBasedFrameDecoder(ByteOrder.BIG_ENDIAN, 64 * 1024, 0, 4, 0, 4, true));
            socketChannel.pipeline().addLast(new StringDecoder(Charset.forName("UTF-8")));
            socketChannel.pipeline().addLast(new NettyCommandHandler());
        }
    }
}

通讯协议解析数据

public class NettyCommandHandler extends ChannelHandlerAdapter {
    private int counter = 0;

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) {
        try {
            String body = (String) msg;
            JsonDataObject request = JsonUtil.fromJson(body, JsonDataObject.class);

            counter = counter + 1;
            JsonDataObject response = new JsonDataObject();
            response.setCode(0);
            response.setMsg("Success");
            response.setData(counter+"");
            String respJson = JsonUtil.toJson(response);

            byte[] respUtf8 = respJson.getBytes("UTF-8");
            int respLength = respUtf8.length;
            ByteBuf respLengthBuf = PooledByteBufAllocator.DEFAULT.buffer(4);
            respLengthBuf.writeInt(respLength);
            respLengthBuf.order(ByteOrder.BIG_ENDIAN);
            ctx.write(respLengthBuf);
            ByteBuf resp = PooledByteBufAllocator.DEFAULT.buffer(respUtf8.length);
            resp.writeBytes(respUtf8);
            ctx.write(resp);
        } catch (Exception e) {
            NettyCommandServer.logger.error(e.getMessage() + "\r\n");
            StringWriter sw = new StringWriter();
            PrintWriter pw = new PrintWriter(sw);
            e.printStackTrace(pw);
            pw.flush();
            sw.flush();
            NettyCommandServer.logger.error(sw.toString());
        }
    }

    @Override
    public void channelReadComplete(ChannelHandlerContext ctx) {
        ctx.flush();
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
        ctx.close();
    }
}

C#客户端代码

    public class SocketClient : Object
    {
        private TcpClient tcpClient;

        public SocketClient()
        {
            tcpClient = new TcpClient();
            tcpClient.Client.Blocking = true;
        }

        public void Connect(string host, int port)
        {
            tcpClient.Connect(host, port);
        }

        public void Disconnect()
        {
            tcpClient.Close();
        }

        public string SendJson(string json)
        {
            byte[] bufferUTF8 = Encoding.UTF8.GetBytes(json);
            int jsonLength = System.Net.IPAddress.HostToNetworkOrder(bufferUTF8.Length); //转换为网络字节顺序，大头结构
            byte[] bufferLength = BitConverter.GetBytes(jsonLength);
            tcpClient.Client.Send(bufferLength, 0, bufferLength.Length, SocketFlags.None); //发送4字节长度
            tcpClient.Client.Send(bufferUTF8, 0, bufferUTF8.Length, SocketFlags.None); //发送Json串内容

            byte[] bufferRecvLength = new byte[sizeof(int)];
            tcpClient.Client.Receive(bufferRecvLength, sizeof(int), SocketFlags.None); //获取长度
            int recvLength = BitConverter.ToInt32(bufferRecvLength, 0);
            recvLength = System.Net.IPAddress.NetworkToHostOrder(recvLength); //转为本地字节顺序
            byte[] bufferRecvUtf8 = new byte[recvLength];
            tcpClient.Client.Receive(bufferRecvUtf8, recvLength, SocketFlags.None);
            string recvCommand = Encoding.UTF8.GetString(bufferRecvUtf8, 0, recvLength);
            return recvCommand;
        }
    }

测试DEMO下载地址： 下载地址

免责声明：此代码只是为了演示Netty性能测试，仅用于学习和研究，切勿用于商业用途。水平有限，错误在所难免，欢迎指正和指导。邮箱地址：[email protected] 。