Netty

Server1

mkdir NettyLB && cd NettyLB

mkdir NettyServer1 && cd NettyServer1

gradle init --type java-application

gradle run
# Hello world.

记得添加.gitignore => "gi gradle >> .gitignore"

vim build.gradle
# compile 'io.netty:netty-all:4.1.25.Final'

mkdir -p src/main/java/server

vim src/main/java/server/ServerHandler.java

package server;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;

import java.nio.charset.Charset;

public class ServerHandler extends ChannelInboundHandlerAdapter {

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        ByteBuf byteBuf = (ByteBuf) msg;
        System.out.println("Server1: " + byteBuf.toString(Charset.forName("utf-8")));
    }
}

mv src/main/java/App.java src/main/java/server/Server.java

vim src/main/java/server/Server.java

package server;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;

public class Server {

    private static final int PORT = 8881;

    public static void main(String[] args) {
        NioEventLoopGroup bossGroup = new NioEventLoopGroup();
        NioEventLoopGroup workerGroup = new NioEventLoopGroup();

        ServerBootstrap serverBootstrap = new ServerBootstrap();
        serverBootstrap
                .group(bossGroup, workerGroup)
                .channel(NioServerSocketChannel.class)
                .option(ChannelOption.SO_BACKLOG, 1024)
                .childOption(ChannelOption.SO_KEEPALIVE, true)
                .childHandler(new ChannelInitializer<NioSocketChannel>() {
                    @Override
                    protected void initChannel(NioSocketChannel ch) throws Exception {
                        ch.pipeline().addLast(new ServerHandler());
                    }
                });

        serverBootstrap.bind(PORT).addListener(future -> {
            if (future.isSuccess()) {
                System.out.println("端口[" + PORT + "] 绑定成功!");
            } else {
                System.err.println("端口[" + PORT + "] 绑定失败!!!");
            }
        });
    }
}

sed -i "" "s/App/server.Server/g" build.gradle && gradle run
# 端口[8881] 绑定成功!
# Server1: hello

telnet 127.0.0.1 8881
# Connected to localhost.
# hello

Server2

cd .. && cp -R NettyServer1 NettyServer2 && cd NettyServer2

sed -i "" "s/8881/8882/g" src/main/java/server/Server.java

sed -i "" "s/Server1/Server2/g" src/main/java/server/ServerHandler.java

sed -i "" "s/App/server.Server/g" build.gradle && gradle run
# 端口[8882] 绑定成功!
# Server2: hello

telnet 127.0.0.1 8882
# Connected to localhost.
# hello

Nginx

nginx -V
# nginx version: nginx/1.13.11
# configure arguments: --with-stream

vim nginx.conf

The ngx_stream_core_module module is available since version 1.9.0. This module is not built by default, it should be enabled with the --with-stream configuration parameter

stream {
    upstream netty {
        server 127.0.0.1:8881;
        server 127.0.0.1:8882;
    }
    server {
        listen 7000;
        proxy_connect_timeout 1s;
        proxy_pass netty;
    }
}

sudo nginx -t

sudo nginx -s reload

# cd NettyServer1
sed -i "" "s/App/server.Server/g" build.gradle && gradle run
# 端口[8881] 绑定成功!
# Server1: yes

# cd NettyServer2
sed -i "" "s/App/server.Server/g" build.gradle && gradle run
# 端口[8882] 绑定成功!
# Server2: no

telnet 127.0.0.1 7000
# Connected to localhost.
# yes

telnet 127.0.0.1 7000
# Connected to localhost.
# no