Hystrix

Hystrix实现容错

增加hystrix依赖

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
        </dependency>

代码

    public List findFallback() {
        return Lists.newArrayList("fall back");
    }

    @HystrixCommand(fallbackMethod = "findFallback")
    @PostMapping("/movie")
    public List find() {
        return  restTemplate.postForObject("http://microservice-provider-user/api/user", null, List.class);
    }

启用Hystrix

启动类增加 @EnableHystrix 注解

测试

启动服务正常返回结果，关闭microservice-provider-user服务，再次调用返回[fall back]

feign使用Hystrix

SpringCloud默认已为Feign整合了Hystrix，下面实现Feign回退：

@Component
public class FeignClientFallBack implements UserFeignClient {
    @Override
    public String find() {
        return "fall back";
    }
}

@FeignClient(name = "microservice-provider-user"
        fallback = FeignClientFallBack.class)
public interface UserFeignClient {

    @PostMapping("/api/user")
    String find();

}

增加feign hystrix配置：

feign:
  hystrix:
    enabled: true