需求：每台机器访问五次后轮询到下一台机器

背景：三台eureka注册中心，三台服务提供者，一台服务消费者

接上篇文章，一些注意事项已经在上篇里提到了，本篇主讲如何修改算法

步骤

.首先继承AbstractLoadBalancerRule
.其次可以将RoundRobinRule中的代码拷贝过来，基于轮询的基础上进行修改

package com.custom.rule;

import com.netflix.client.config.IClientConfig;
import com.netflix.loadbalancer.AbstractLoadBalancerRule;
import com.netflix.loadbalancer.ILoadBalancer;
import com.netflix.loadbalancer.RoundRobinRule;
import com.netflix.loadbalancer.Server;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;

public class RoundRobinRule_ltt  extends AbstractLoadBalancerRule {

    private AtomicInteger total;

    private AtomicInteger current;


    private static Logger log = LoggerFactory.getLogger(RoundRobinRule_ltt.class);

    public RoundRobinRule_ltt() {
        total = new AtomicInteger(0);
        current = new AtomicInteger(0);
    }

    public Server choose(ILoadBalancer lb, Object key) {
        if (lb == null) {
            log.warn("no load balancer");
            return null;
        }

        Server server = null;
        int count = 0;
        while (server == null && count++ < 10) {
            List<Server> reachableServers = lb.getReachableServers();
            List<Server> allServers = lb.getAllServers();
            int upCount = reachableServers.size();
            int serverCount = allServers.size();

            if ((upCount == 0) || (serverCount == 0)) {
                log.warn("No up servers available from load balancer: " + lb);
                return null;
            }
            if(total.intValue()<5){
                total.incrementAndGet();
                server = allServers.get(current.get());
            }else{
                total = new AtomicInteger(0);
                current.incrementAndGet();
                if (current.get()>=serverCount){
                    current.set(0);
                }
            }
            if (server == null) {
                /* Transient. */
                Thread.yield();
                continue;
            }

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

            // Next.
            server = null;
        }

        if (count >= 10) {
            log.warn("No available alive servers after 10 tries from load balancer: "
                    + lb);
        }
        return server;
    }

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

    @Override
    public void initWithNiwsConfig(IClientConfig clientConfig) {
    }
}

主要修改如下图：

choose方法中的修改