Srping cloud Ribbon 自定义负载均衡

IRule 默认提供有7种方式，使用轮询方式

如何自定义

1:主启动类加@RibbonClient

@RibbonClient(name="微服务名", configuration=MySelfRule.class)

也就是说MySelfRule.java不能和@SpringBootApplication注释的类在同一包下.

MySelfRule.java

package com.atguigu.myrule;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import com.netflix.loadbalancer.IRule;
import com.netflix.loadbalancer.RoundRobinRule;

@Configuration
public class MySelfRule
{
    @Bean
    public IRule myRule()
    {
        //return new RandomRule();// Ribbon默认是轮询，我自定义为随机
        //return new RoundRobinRule();// Ribbon默认是轮询，我自定义为随机

        return new RandomRule_ZY();// 我自定义为每台机器5次
    }
}

package com.atguigu.myrule;

import java.util.List;

import com.netflix.client.config.IClientConfig;
import com.netflix.loadbalancer.AbstractLoadBalancerRule;
import com.netflix.loadbalancer.ILoadBalancer;
import com.netflix.loadbalancer.Server;

public class RandomRule_ZY extends AbstractLoadBalancerRule
{

    // total = 0 // 当total==5以后，我们指针才能往下走，
    // index = 0 // 当前对外提供服务的服务器地址，
    // total需要重新置为零，但是已经达到过一个5次，我们的index = 1
    // 分析：我们5次，但是微服务只有8001 8002 8003 三台，OK？
    // 

    private int total = 0;             // 总共被调用的次数，目前要求每台被调用5次
    private int currentIndex = 0;    // 当前提供服务的机器号

    public Server choose(ILoadBalancer lb, Object key)
    {
        if (lb == null) {
            return null;
        }
        Server server = null;

        while (server == null) {
            if (Thread.interrupted()) {
                return null;
            }
            List<Server> upList = lb.getReachableServers();
            List<Server> allList = lb.getAllServers();

            int serverCount = allList.size();
            if (serverCount == 0) {
                /*
                 * No servers. End regardless of pass, because subsequent passes only get more
                 * restrictive.
                 */
                return null;
            }

//            int index = rand.nextInt(serverCount);// java.util.Random().nextInt(3);
//            server = upList.get(index);

//            private int total = 0;             // 总共被调用的次数，目前要求每台被调用5次
//            private int currentIndex = 0;    // 当前提供服务的机器号
            if(total < 5)
            {
                server = upList.get(currentIndex);
                total++;
            }else {
                total = 0;
                currentIndex++;
                if(currentIndex >= upList.size())
                {
                  currentIndex = 0;
                }
            }            

            if (server == null) {
                /*
                 * The only time this should happen is if the server list were somehow trimmed.
                 * This is a transient condition. Retry after yielding.
                 */
                Thread.yield();
                continue;
            }

            if (server.isAlive()) {
                return (server);
            }

            // Shouldn‘t actually happen.. but must be transient or a bug.
            server = null;
            Thread.yield();
        }

        return server;

    }

    @Override
    public Server choose(Object key)
    {
        return choose(getLoadBalancer(), key);
    }

    @Override
    public void initWithNiwsConfig(IClientConfig clientConfig)
    {
        // TODO Auto-generated method stub

    }

}

原文地址：https://www.cnblogs.com/eason-d/p/9484603.html