SpringCloud（12）：LoadBalance：自定义负载均衡算法

迷南。 2023-01-11 09:10 125阅读 0赞

### 一、切换随机负载均衡 ###

查看源码可以看到ReactiveLoadBalancer接口下有两个实现。随机和轮询。

![20210126185021611.png][]

（1）切换RandomLoadBalancer，编写配置类：

package com.buba.loadbalancer;
    
    import org.springframework.cloud.client.ServiceInstance;
    import org.springframework.cloud.loadbalancer.core.RandomLoadBalancer;
    import org.springframework.cloud.loadbalancer.core.ReactorLoadBalancer;
    import org.springframework.cloud.loadbalancer.core.ServiceInstanceListSupplier;
    import org.springframework.cloud.loadbalancer.support.LoadBalancerClientFactory;
    import org.springframework.context.annotation.Bean;
    import org.springframework.core.env.Environment;
    
    /**
     * 客户端负载均衡配置
     */
    public class CustomLoadBalancerConfiguration {
    
        @Bean
        ReactorLoadBalancer<ServiceInstance> randomLoadBalancer(Environment environment,
                                                                LoadBalancerClientFactory loadBalancerClientFactory) {
            String name = environment.getProperty(LoadBalancerClientFactory.PROPERTY_NAME);
            return new RandomLoadBalancer(loadBalancerClientFactory
                    .getLazyProvider(name, ServiceInstanceListSupplier.class),
                    name);
        }
    }

（2）@LoadBalancerClients注解设置默认配置文件

package com.buba.springcloud.config;
    
    import com.buba.loadbalancer.CustomLoadBalancerConfiguration;
    import org.springframework.cloud.client.loadbalancer.LoadBalanced;
    import org.springframework.cloud.loadbalancer.annotation.LoadBalancerClient;
    import org.springframework.cloud.loadbalancer.annotation.LoadBalancerClients;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.web.client.RestTemplate;
    
    /**
     * @Configuration 相当于applicationContext.xml
     */
    @Configuration
    @LoadBalancerClients(defaultConfiguration = {CustomLoadBalancerConfiguration.class})
    public class ConfigBean {
    
        /**
         * @return
         * @LoadBalanced 配置负载均衡到RestTemplate
         * 把RestTemplate对象交给Spring管理
         */
        @Bean
        @LoadBalanced
        public RestTemplate getRestTemplate() {
            return new RestTemplate();
        }
    
    }

（3）启动测试

重复访问[http://localhost/consumer/dept/list][http_localhost_consumer_dept_list]，可以看到数据随机从某个服务提供者中获取：

![20210126202836669.png][]

[20210126185021611.png]: /images/20221119/8faeff2616304fd486b28926f86c32aa.png
[http_localhost_consumer_dept_list]: http://localhost/consumer/dept/list
[20210126202836669.png]: /images/20221119/74dfdda5eb3c467badc837d02579fc0e.png