springcloud-eureka集群-自定义负载均衡规则

àì夳堔傛蜴生んèń 2022-05-13 22:21 229阅读 0赞

1、首先在服务调用者项目中实现IRule接口，用随机数控制调用服务的端口

import java.util.List;
    import java.util.Random;
    import com.netflix.loadbalancer.ILoadBalancer;
    import com.netflix.loadbalancer.IRule;
    import com.netflix.loadbalancer.Server;
    
    /**
     * 自定义负载均衡规则
     */
    public class MyRule implements IRule {
       
       private ILoadBalancer lb;
    
       public Server choose(Object key) {
          Random r = new Random();
          int randomNum = r.nextInt(10);
          List<Server> servers = lb.getAllServers();
          if(randomNum > 7) {
             Server s = getServerByPort(servers, 8081);
             return s;
          }
          return getServerByPort(servers, 8082);
       }
       
       private Server getServerByPort(List<Server> servers, int port) {
          for(Server s : servers) {
             if(s.getPort() == port) {
                return s;
             }
          }
          return null;
       }
    
       public void setLoadBalancer(ILoadBalancer lb) {
          this.lb = lb;
       }
    
       public ILoadBalancer getLoadBalancer() {
          return lb;
       }
    
    }

2、将该接口注入spring容器

@Configuration
    public class BaseConfig {
        @Bean
        @LoadBalanced
        public RestTemplate getRestTemplate(){
            return new RestTemplate();
        }
    
        @Bean
        public IRule getRule(){
            return new MyRule();
        }
    }

或者在application.yml中加入配置

eureka-service:
      ribbon:
        NFLoadBalancerRuleClassName: 包路径.MyRule

3、编写controller测试类，eureka-service是服务提供者的spring.application.name

@RestController
    public class MyRestController {
    
        @Autowired
        private RestTemplate restTemplate;
    
        /**
         * 调用服务提供者的接口
         *
         * @param id
         * @return
         */
        @GetMapping(value = "/getUser/{id}", produces = MediaType.APPLICATION_JSON_UTF8_VALUE)
        public String getUser(@PathVariable Integer id) {
            String templateUrl = "http://eureka-service/getUser/" + id;
            String result = restTemplate.getForObject(templateUrl, String.class);
            return result;
        }
    
    }

在服务提供者项目中编写controller接口，为服务调用者提供服务，该接口将服务提供者实例的url返回，用来验证自定义负载均衡规则。

@GetMapping(value = "/getUser/{id}", produces = MediaType.APPLICATION_JSON_UTF8_VALUE)
    public User getUser(@PathVariable Integer id, HttpServletRequest request){
        User user = new User();
        user.setId(id);
        user.setUsername("中文");
        user.setPassword("123");
        user.setPort(request.getRequestURL().toString());
        return user;
    }

启动项目并测试接口，这里的服务端口的调用会按照随机数大于7调用8081端口，否则调用8082端口的规则来执行

![70][]

[70]: /images/20220514/696bd58da47a4c08a174ba49ca715f57.png