Fork me on GitHub

跟我学Spring Cloud(Finchley版)-14-Feign使用Hystrix

Feign默认已经整合了Hystrix,本节详细探讨Feign使用Hystrix的具体细节。

服务降级

  • 加配置,默认Feign是不启用Hystrix的,需要添加如下配置启用Hystrix,这样所有的Feign Client都会受到Hystrix保护!

    1
    2
    3
    feign:
    hystrix:
    enabled: true
  • 提供Fallback:

    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    @FeignClient(name = "microservice-provider-user", fallback = UserFeignClientFallback.class)
    public interface UserFeignClient {
    @GetMapping("/users/{id}")
    User findById(@PathVariable("id") Long id);
    }

    @Component
    class UserFeignClientFallback implements UserFeignClient {
    @Override
    public User findById(Long id) {
    return new User(id, "默认用户", "默认用户", 0, new BigDecimal(1));
    }
    }

获得造成fallback的原因

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
@FeignClient(name = "microservice-provider-user", fallbackFactory = UserFeignClientFallbackFactory.class)
public interface UserFeignClient {
@GetMapping("/users/{id}")
User findById(@PathVariable("id") Long id);
}

@Component
@Slf4j
class UserFeignClientFallbackFactory implements FallbackFactory<UserFeignClient> {
@Override
public UserFeignClient create(Throwable throwable) {
return new UserFeignClient() {
@Override
public User findById(Long id) {
log.error("进入回退逻辑", throwable);
return new User(id, "默认用户", "默认用户", 0, new BigDecimal(1));
}
};
}
}

Feign启用/禁用Hystrix

全局启用

1
feign.hystrix.enabled: true

全局禁用

1
feign.hystrix.enabled: false

或直接省略不写。

局部启用

利用Feign配置的自定义,为指定Feign Client指定如下配置类即可,Feign配置自定义详见:跟我学Spring Cloud(Finchley版)-10-Feign深入

1
2
3
4
5
6
7
public class FeignDisableHystrixConfiguration {
@Bean
@Scope("prototype")
public HystrixFeign.Builder feignBuilder() {
return HystrixFeign.builder();
}
}

局部禁用

1
2
3
4
5
6
7
public class FeignDisableHystrixConfiguration {
@Bean
@Scope("prototype")
public Feign.Builder feignBuilder() {
return Feign.builder();
}
}

配套代码

服务降级:

获得造成fallback的原因:

相关文章

评论系统未开启,无法评论!