SpringCloudAlibaba - 扩展 Ribbon 同集群优先调用

前言
- 环境
测试用例
具体实现

前言

记录下Ribbon优先调用同一集群下实例的实现

环境

Spring Cloud Hoxton.SR9 + Spring Cloud Alibaba 2.2.6.RELEASE + Nacos 1.4.2

测试用例

测试内容

实现内容中心调用用户中心时优先调用同一集群下实例

用户中心 user-center

TestController.java

@RestController
@Slf4j
public class TestController {

    @GetMapping("/test/{name}")
    public String test(@PathVariable String name) {
        log.info("请求...");
        return "hello " + name;
    }

}

内容中心 content-center

TestController.java

@GetMapping("test3")
public String test3() {
    return restTemplate.getForObject(
            "http://user-center/test/{name}",
            String.class,
            "Coisini"
    );
}

具体实现

代码配置

服务消费者（内容中心）配置如下：
NacosSameClusterWeightedRule.java

import com.alibaba.cloud.nacos.NacosDiscoveryProperties;
import com.alibaba.cloud.nacos.ribbon.ExtendBalancer;
import com.alibaba.cloud.nacos.ribbon.NacosServer;
import com.alibaba.nacos.api.exception.NacosException;
import com.alibaba.nacos.api.naming.NamingService;
import com.alibaba.nacos.api.naming.pojo.Instance;
import com.netflix.client.config.IClientConfig;
import com.netflix.loadbalancer.AbstractLoadBalancerRule;
import com.netflix.loadbalancer.BaseLoadBalancer;
import com.netflix.loadbalancer.Server;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.util.CollectionUtils;
import java.util.ArrayList;
import java.util.List;
import java.util.Objects;
import java.util.stream.Collectors;

/**
 * @Description Ribbon-同一集群优先调用
 */
@Slf4j
public class NacosSameClusterWeightedRule extends AbstractLoadBalancerRule {

    @Autowired
    private NacosDiscoveryProperties nacosDiscoveryProperties;

    /**
     * 读取配置文件，并初始化 NacosWeightedRule
     * @param iClientConfig
     */
    @Override
    public void initWithNiwsConfig(IClientConfig iClientConfig) {

    }

    /**
     * 同一集群优先调用
     * @param o
     * @return
     */
    @Override
    public Server choose(Object o) {

        try {
            // 拿到配置文件中的集群名称 kunming
            String clusterName = nacosDiscoveryProperties.getClusterName();

            BaseLoadBalancer loadBalancer = (BaseLoadBalancer) this.getLoadBalancer();
            // 想要请求的微服务的名称
            String name = loadBalancer.getName();

            // 拿到服务发现的相关API
            NamingService namingService = nacosDiscoveryProperties.namingServiceInstance();

            // 1. 找到指定服务的所有实例 A
            List<Instance> instances = namingService.selectInstances(name, true);

            // 2. 过滤出相同集群下的所有实例 B
            List<Instance> sameClusterInstances = instances.stream()
                    .filter(instance -> Objects.equals(instance.getClusterName(), clusterName))
                    .collect(Collectors.toList());

            // 3. 如果B是空，就用A
            List<Instance> instancesToBeChosen = new ArrayList<>();
            if (CollectionUtils.isEmpty(sameClusterInstances)) {
                instancesToBeChosen = instances;
                log.warn("发生跨集群的调用, name = {}, clusterName = {}, instances = {}",
                        name,
                        clusterName,
                        instances
                );
            } else {
                instancesToBeChosen = sameClusterInstances;
            }

            // 4. 基于权重的负载均衡算法，返回1个实例
            Instance instance = ExtendBalancer.getHostByRandomWeight2(instancesToBeChosen);
            log.info("选择的实例是 port = {}, instance = {}", instance.getPort(), instance);

            return new NacosServer(instance);
        } catch (NacosException e) {
            log.error("Nacos同一集群优先调用异常", e);
            return null;
        }
    }
}

RibbonConfiguration.java

import com.coisini.contentcenter.configuration.NacosSameClusterWeightedRule;
import com.netflix.loadbalancer.IRule;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

/**
 * @Description Ribbon配置类
 */
@Configuration
public class RibbonConfiguration {
    /**
     * 自定义负载均衡规则
     * NacosSameClusterWeightedRule 同集群优先调用
     * @return
     */
    @Bean
    public IRule ribbonRule() {
        return new NacosSameClusterWeightedRule();
    }
}

UserCenterRibbonConfiguration.java

import org.springframework.cloud.netflix.ribbon.RibbonClients;
import org.springframework.context.annotation.Configuration;
import ribbonconfiguration.RibbonConfiguration;

/**
 * @Description 用户中心配置类
 */
@Configuration
@RibbonClients(defaultConfiguration = RibbonConfiguration.class)
public class UserCenterRibbonConfiguration {
}

content-center -> application.yml，内容中心配置集群为kunming

spring:
  application:
    # 服务名称
    name: content-center
  cloud:
    nacos:
      discovery:
        # 指定nacos server的地址
        server-addr: localhost:8848
        # 集群名称 kunming 
        cluster-name: kunming

测试

user-center -> application.yml，启动用户中心双实例，集群-端口分别为yuxi-8081，kunming-8082

# 8081 端口 实例1
spring:
  application:
    # 服务名称
    name: user-center
  cloud:
    nacos:
      discovery:
        # 指定nacos server的地址
        server-addr: localhost:8848
        # 指定集群名称
        cluster-name: yuxi

# 8082 端口 实例2
spring:
  application:
    # 服务名称
    name: user-center
  cloud:
    nacos:
      discovery:
        # 指定nacos server的地址
        server-addr: localhost:8848
        # 指定集群名称
        cluster-name: kunming