一、Ribbon中的负载均衡策略

1、Ribbon中支持的负载均衡策略

AvailabilityFilteringRule:过滤掉那些因为一直连接失败的被标记为circuit tripped的后端server,并过滤掉那些高并发的的后端server(active connections 超过配置的阈值) | 使用一个AvailabilityPredicate来包含过滤server的逻辑,其实就就是检查status里记录的各个server的运行状态

RandomRule:随机选择一个server

BestAvailabl:选择一个最小的并发请求的server,逐个考察Server,如果Server被tripped了,则忽略

RoundRobinRule:roundRobin方式轮询选择, 轮询index,选择index对应位置的server

WeightedResponseTimeRule:根据响应时间分配一个weight(权重),响应时间越长,weight越小,被选中的可能性越低

RetryRule:对选定的负载均衡策略机上重试机制,在一个配置时间段内当选择server不成功,则一直尝试使用subRule的方式选择一个可用的server

ZoneAvoidanceRule:复合判断server所在区域的性能和server的可用性选择server

ResponseTimeWeightedRule:作用同WeightedResponseTimeRule,二者作用是一样的,ResponseTimeWeightedRule后来改名为WeightedResponseTimeRule

二、验证

1、自定义负载均衡策略

  1. # 自定义负载均衡策略   
    springboot-h2.ribbon.NFLoadBalancerRuleClassName=com.netflix.loadbalancer.RandomRule // 自定义使用随机策略,springboot-h2是服务应用名 
     

2、修改调用代码

package com.chhliu.springboot.restful.controller;   
   
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.GetMapping;   
import org.springframework.web.bind.annotation.PathVariable;   
import org.springframework.web.bind.annotation.RestController;   
import org.springframework.web.client.RestTemplate;   
   
import com.chhliu.springboot.restful.vo.User;   
   
@RestController   
public class RestTemplateController {   
    @Autowired   
    private RestTemplate restTemplate;   
       
    @Autowired   
    private LoadBalancerClient loadBalancerClient;   
       
    @GetMapping("/template/{id}")   
    public User findById(@PathVariable Long id) {   
        ServiceInstance serviceInstance = this.loadBalancerClient.choose("springboot-h2");   
        System.out.println("===" + ":" + serviceInstance.getServiceId() + ":" + serviceInstance.getHost() + ":"   
                + serviceInstance.getPort());// 打印当前调用服务的信息   
        User u = this.restTemplate.getForObject("http://springboot-h2/user/" + id, User.class);   
        System.out.println(u);   
        return u;   
    }   
}  

 

3、测试

 

服务调用关系如下:

测试结果如下:

 

 在CODE上查看代码片派生到我的代码片
  1. ===:springboot-h2:127.0.0.1:7902   
    User [id=2, username=user2, name=李四, age=20, balance=100.00]   
    ===:springboot-h2:127.0.0.1:7901   
    User [id=2, username=user2, name=李四, age=20, balance=100.00]   
    ===:springboot-h2:127.0.0.1:7902   
    User [id=2, username=user2, name=李四, age=20, balance=100.00]   
    ===:springboot-h2:127.0.0.1:7901   
    User [id=2, username=user2, name=李四, age=20, balance=100.00]   
    ===:springboot-h2:127.0.0.1:7902   
    User [id=2, username=user2, name=李四, age=20, balance=100.00]   
    ===:springboot-h2:127.0.0.1:7902   
    User [id=2, username=user2, name=李四, age=20, balance=100.00]   
    ===:springboot-h2:127.0.0.1:7902   
    User [id=2, username=user2, name=李四, age=20, balance=100.00]   
    ===:springboot-h2:127.0.0.1:7902   
    User [id=2, username=user2, name=李四, age=20, balance=100.00]   
    ===:springboot-h2:127.0.0.1:7902   
    User [id=2, username=user2, name=李四, age=20, balance=100.00]   
    ===:springboot-h2:127.0.0.1:7901   
    User [id=2, username=user2, name=李四, age=20, balance=100.00]   
    ===:springboot-h2:127.0.0.1:7901   
    User [id=2, username=user2, name=李四, age=20, balance=100.00]   
    ===:springboot-h2:127.0.0.1:7902   
    User [id=2, username=user2, name=李四, age=20, balance=100.00]   
    ===:springboot-h2:127.0.0.1:7902   
    User [id=2, username=user2, name=李四, age=20, balance=100.00]   
    ===:springboot-h2:127.0.0.1:7901   
    User [id=2, username=user2, name=李四, age=20, balance=100.00]   
    ===:springboot-h2:127.0.0.1:7901   
    User [id=2, username=user2, name=李四, age=20, balance=100.00]   
    发现选择7901端口服务和7902端口服务确实是随机的!

     

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Spring Cloud 通过代码自定义配置Ribbon详解
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