The ribbon has seven load balancing strategies to choose from:

If you want to create a global load policy, you only need to add a configuration class, or you can expand it by yourself and add logic, as follows:

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import com.netflix.client.config.IClientConfig;
import com.netflix.loadbalancer.IRule;
import com.netflix.loadbalancer.RandomRule;

@Configuration
public class RibbonConfiguration {

    @Bean
    public IRule ribbonRule() {
        return new RandomRule();
    }
}

If you want to set a specific policy for a service source, you can add @ RibbonClient annotation on the project startup class. Of course, the corresponding configuration code needs to be adjusted:

/**
 * Custom - Tag annotation
 */
public @interface AvoidScan {

}

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import com.netflix.client.config.IClientConfig;
import com.netflix.loadbalancer.IRule;
import com.netflix.loadbalancer.RandomRule;

/**
 * Ribbon Load policy configuration class. IClientConfig is a management configurator for clients, which is used with @ RibbonClient annotation.
 */
@Configuration
@AvoidScan
public class RibbonConfiguration {

    @Autowired
    private IClientConfig config;

    @Bean
    public IRule ribbonRule(IClientConfig config) {
        return new RandomRule();
    }
}

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.netflix.ribbon.RibbonClient;
import org.springframework.cloud.netflix.ribbon.RibbonClients;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.FilterType;
import cn.springcloud.book.config.AvoidScan;
import cn.springcloud.book.config.TestConfiguration;

/**
 * Project startup
 */
@SpringBootApplication
@EnableDiscoveryClient
@RibbonClient(name = "client-a", configuration = RibbonConfiguration.class)//Indicates client-a The responsible strategy for service usage is RibbonConfiguration Of the configuration class.
//@RibbonClients(value = {
//        @RibbonClient(name = "client-a", configuration = RibbonConfiguration.class),
//        @RibbonClient(name = "client-b", configuration = RibbonConfiguration.class)
//})//This way@RibbonClient Similar, but this is a policy specification for multiple services.
@ComponentScan(excludeFilters = {@ComponentScan.Filter(type = FilterType.ANNOTATION, value = {AvoidScan.class})})//When the project is started, it is not allowed to Spring Scanned@AvoidScan Annotated classes,
                                                                                                                 //Because the load policy configured for special services is not global. If it is not excluded, an error will be reported at startup.
public class RibbonLoadbalancerApplication {

    public static void main(String[] args) {
        SpringApplication.run(RibbonLoadbalancerApplication.class, args);
    }

}

If you want to use the configuration file method to configure the responsible policy, the syntax is client name.ribbon. *, and client name is the name we give to the service, that is, the value set by spring.application.name. As follows:

client-a:
  ribbon:
    NFLoadBalancerRuleClassName: com.netflix.loadbalancer.RandomRule #Using random strategy for client-a service