spring cloud ribbon 断路器

@EnableDiscoveryClient
@SpringBootApplication
@EnableCircuitBreaker //开启断路器
public class ConsumerMovieApplication {
  @Bean
  @LoadBalanced
  public RestTemplate restTemplate() {
    return new RestTemplate();
  }

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

　　

 调用了findByIdFallback，并不代表使用了断路器，可以通过 /health 查看是否启用了断路器

@RestController
public class MovieController {
  private static final Logger LOGGER = LoggerFactory.getLogger(MovieController.class);
  @Autowired
  private RestTemplate restTemplate;
  @Autowired
  private LoadBalancerClient loadBalancerClient;


  //断路器 配置 fallbackMethod ，返回值和参数与调用一致
  @HystrixCommand(fallbackMethod = "findByIdFallback")
  @GetMapping("/user/{id}")
  public User findById(@PathVariable Long id) {
    // 当microservice-provider-user 挂掉了，就返回 findByIdFallback，而不在调用服务了
    return this.restTemplate.getForObject("http://microservice-provider-user/" + id, User.class);
  }

  public User findByIdFallback(Long id) {
    User user = new User();
    user.setId(-1L);
    user.setName("默认用户");
    return user;
  }

  @GetMapping("/log-user-instance")
  public void logUserInstance() {
    ServiceInstance serviceInstance = this.loadBalancerClient.choose("microservice-provider-user");
    // 打印当前选择的是哪个节点
    MovieController.LOGGER.info("{}:{}:{}", serviceInstance.getServiceId(), serviceInstance.getHost(), serviceInstance.getPort());
  }
}

　　

1.如何实现自定义路由算法

　　1.实现 IRule 接口

      2.实例化 接口

2.为服务名称users 配置 IRule

users.ribbon.NFLoadBalancerRuleClassName: com.netflix.loadbalancer.WeightedResponseTimeRule

3.设置调用服务的超时配置

hystrix.command.default.execution.isolation.thread.timeoutInMilliseconds: 60000

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