Ribbon：自定义负载均衡算法

在springcloud同级，与启动类所在包不同级创建myrule包，写MyWTYRule配置

Spring Cloud还允许您通过使用@RibbonClient声明其他配置（位于RibbonClientConfiguration之上）来完全控制客户端。例：

@Configuration
@RibbonClient(name = "foo", configuration = FooConfiguration.class)
public class TestConfiguration {
}

在这种情况下，客户端由RibbonClientConfiguration中已经存在的组件与FooConfiguration中的任何组件组成（后者通常会覆盖前者）。

再写自定义负载均衡配置RandRule.java

 1 package com.company.myrule;
 2 
 3 
 4 import com.netflix.client.config.IClientConfig;
 5 import com.netflix.loadbalancer.AbstractLoadBalancerRule;
 6 import com.netflix.loadbalancer.ILoadBalancer;
 7 import com.netflix.loadbalancer.Server;
 8 
 9 import java.util.List;
10 
11 
12 public class RandRule extends AbstractLoadBalancerRule {
13 
14 
15     //每个服务，访问5次后换下一个服务（3个）
16 
17     private int total = 0; //被调用的次数
18     private int currentIndex = 0; //当前是谁在提供服务
19     public Server choose(ILoadBalancer lb, Object key) {
20         System.out.println("=========================================");
21         if (lb == null) {
22             return null;
23         }
24         Server server = null;
25 
26         while (server == null) {
27             if (Thread.interrupted()) {
28                 return null;
29             }
30             List<Server> upList = lb.getReachableServers(); //获得还活着的服务
31             List<Server> allList = lb.getAllServers(); //获取全部服务
32 
33             int serverCount = allList.size();
34             if (serverCount == 0) {
35 
36                 return null;
37             }
38 
39             //int index = chooseRandomInt(serverCount);
40             //server = upList.get(index);
41 
42             if (total<5){
43                 server = upList.get(currentIndex);
44                 total++;
45                 System.out.println("<5"+total+":"+currentIndex);
46             }else {
47                 total=0;
48                 currentIndex++;
49                 if (currentIndex>upList.size()-1){
50                     currentIndex = 0;
51                     System.out.println(">size"+total+":"+currentIndex);
52                 }
53                 server = upList.get(currentIndex);
54                 System.out.println(">5"+total+":"+currentIndex);
55             }
56 
57             if (server == null) {
58 
59                 Thread.yield();
60                 continue;
61             }
62 
63             if (server.isAlive()) {
64                 return (server);
65             }
66 
67 
68             server = null;
69             Thread.yield();
70         }
71 
72         return server;
73 
74     }
75 
76     //protected int chooseRandomInt(int serverCount) {
77     //    return ThreadLocalRandom.current().nextInt(serverCount);
78     //}
79 
80     @Override
81     public Server choose(Object key) {
82         return choose(getLoadBalancer(), key);
83     }
84 
85     @Override
86     public void initWithNiwsConfig(IClientConfig clientConfig) {
87         // TODO Auto-generated method stub
88 
89     }
90 }

主启动类添加注解@RibbonClient(name="XXXX",configuration=XXXRule.class)