一、介绍

• 1.什么是Ribbon
  • Spring Cloud Ribbon软件系统定制开发是一个基于HTTP和TCP软件系统定制开发的客户端负载均衡工具，它基于Netflix Ribbon实现。通过Spring Cloud的封装，可以让我们轻松地将面向服务的REST模版请求自动转换成客户端负载均衡的服务调用

二、Ribbon-算法

• 1.OrderToMemberService
  • 由于默认就已经引入了Ribbon，所以不需要单独的引用依赖

import org.springframework.beans.factory.annotation.Autowired;import org.springframework.cloud.client.ServiceInstance;import org.springframework.cloud.client.loadbalancer.LoadBalancerClient;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RestController;import org.springframework.web.client.RestTemplate;@RestControllerpublic class OrderToMemberService {    @Autowired    private RestTemplate restTemplate;    @Autowired    private LoadBalancerClient loadBalancerClient;    @RequestMapping("/orderToMember")    public String orderToMember() {        /*         * 根据服务名称 从注册中心 获取 会员的接口地址         * 服务提供 启动多个集群         *         */         //默认采用轮询机制        ServiceInstance serviceInstance = loadBalancerClient.choose("sjyl-producer-member");        // 会员服务的ip和端口        String memberUrl = "http://" + serviceInstance.getHost() + ":" + serviceInstance.getPort() + "/" + "getMember";        return "订单服务调用会员服务:" + restTemplate.getForObject(memberUrl, String.class) + "...端口：" + serviceInstance.getPort();    }}
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三、Ribbon-

• 1.新建一个LoadBalancerConfig
  • 这个主要就是为了注入RandomRule，这样Ribbon就会采用随机算法
  • OrderToMemberService不需要修改

import com.netflix.loadbalancer.RandomRule;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;@Configurationpublic class LoadBalanceConfig {    @Bean    public RandomRule randomRule(){        return  new RandomRule();    }}
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四、Ribbon整合Nacos权重算法

• 1.注意
  • 算法只能注入一个，不能注入多个
  • 否则Ribbon就无法知道要采用哪个算法
  • 所以这里需要将之前的Ribbon随机算法注释掉

@Configurationpublic class LoadBalanceConfig {//    @Bean//    public RandomRule randomRule(){//        return  new RandomRule();//    }}
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• 2.新建SjylWeightLoadBalance
  • 需要自己实现权重算法
  • OrderToMemberService不需要修改

import com.netflix.client.config.IClientConfig;import com.netflix.loadbalancer.AbstractLoadBalancerRule;import com.netflix.loadbalancer.ILoadBalancer;import com.netflix.loadbalancer.Server;import org.springframework.cloud.alibaba.nacos.ribbon.NacosServer;import org.springframework.stereotype.Component;import java.util.ArrayList;import java.util.List;import java.util.concurrent.atomic.AtomicInteger;@Componentpublic class SjylWeightLoadBalance extends AbstractLoadBalancerRule {    @Override    public void initWithNiwsConfig(IClientConfig iClientConfig) {    }    private AtomicInteger countAtomicInteger = new AtomicInteger(0);    @Override    public Server choose(Object key) {        return choose(getLoadBalancer(), key);    }    public Server choose(ILoadBalancer lb, Object key) {        if (lb == null) {            return null;        }        List<Server> upList = lb.getReachableServers();//获取上线的地址，不包括下线的地址        ArrayList<NacosServer> newNacosServers = new ArrayList<>();        upList.forEach((s) -> {            NacosServer nacosServer = (NacosServer) s;            double weight = nacosServer.getInstance().getWeight();            for (int i = 0; i < weight; ++i) {                newNacosServers.add(nacosServer);            }        });        return newNacosServers.get(countAtomicInteger.incrementAndGet() % newNacosServers.size());    }}
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