大型企业网站欣赏/杭州最好的电商培训机构

服务发现的领域模型

• NameSpace：实线隔离，默认public
• Group:不同服务可以分到一个组，默认DEFAULT_GROUP
• service：微服务
• cluster：对指定微服务的一个虚拟划分，默认Default
• instance：微服务实例

 ribboon的父子上下文重叠，ribbon的懒加载。

自定义权重策略

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.*;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.alibaba.nacos.NacosDiscoveryProperties;
import org.springframework.cloud.alibaba.nacos.ribbon.NacosServer;@Slf4j
public class NacosWeightedRule extends AbstractLoadBalancerRule {@Autowiredprivate NacosDiscoveryProperties nacosDiscoveryProperties;@Overridepublic void initWithNiwsConfig(IClientConfig clientConfig) {// 读取配置文件，并初始化NacosWeightedRule}@Overridepublic Server choose(Object key) {try {BaseLoadBalancer loadBalancer = (BaseLoadBalancer) this.getLoadBalancer();
//        log.info("lb = {}", loadBalancer);// 想要请求的微服务的名称String name = loadBalancer.getName();// 拿到服务发现的相关APINamingService namingService = nacosDiscoveryProperties.namingServiceInstance();// nacos client自动通过基于权重的负载均衡算法，给我们选择一个实例。Instance instance = namingService.selectOneHealthyInstance(name);log.info("选择的实例是：port = {}, instance = {}", instance.getPort(), instance);return new NacosServer(instance);} catch (NacosException e) {return null;}}
}// spring cloud commons --> 定义了标准
// spring cloud loadbalancer --> 没有权重

自定义同集群策略

import com.alibaba.nacos.api.exception.NacosException;
import com.alibaba.nacos.api.naming.NamingService;
import com.alibaba.nacos.api.naming.pojo.Instance;
import com.alibaba.nacos.client.naming.core.Balancer;
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.cloud.alibaba.nacos.NacosDiscoveryProperties;
import org.springframework.cloud.alibaba.nacos.ribbon.NacosServer;
import org.springframework.util.CollectionUtils;import java.util.ArrayList;
import java.util.List;
import java.util.Objects;
import java.util.stream.Collectors;@Slf4j
public class NacosSameClusterWeightedRule extends AbstractLoadBalancerRule {@Autowiredprivate NacosDiscoveryProperties nacosDiscoveryProperties;@Overridepublic void initWithNiwsConfig(IClientConfig clientConfig) {}@Overridepublic Server choose(Object key) {try {// 拿到配置文件中的集群名称 BJString 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APINamingService namingService = nacosDiscoveryProperties.namingServiceInstance();// 1. 找到指定服务的所有实例 AList<Instance> instances = namingService.selectInstances(name, true);// 2. 过滤出相同集群下的所有实例 BList<Instance> sameClusterInstances = instances.stream().filter(instance -> Objects.equals(instance.getClusterName(), clusterName)).collect(Collectors.toList());// 3. 如果B是空，就用AList<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("发生异常了", e);return null;}}
}class ExtendBalancer extends Balancer {public static Instance getHostByRandomWeight2(List<Instance> hosts) {return getHostByRandomWeight(hosts);}
}