SpringBoot在@PostConstruct方法中调用FeignClient加载不到Hystrix配置问题

版本信息#

spring-cloud-starter-openfeign：2.1.3.RELEASE
spring-boot-starter-parent：2.2.2.RELEASE

问题描述#

@Service类@Autowired了一个@FeignClient，在@PostConstruct方法中调用此@FeignClient的方法，会直接进入Fallback，怀疑配置的Hystrix超时timeoutInMilliseconds配置没有生效

配置&代码#

application. yml

hystrix:
  threadpool:
    default:
      coreSize: 30
      maximumSize: 100
  command:
    default:
      execution:
        isolation:
          thread:
            timeoutInMilliseconds: 9000
feign:
  hystrix:
    enabled: true
  httpclient:
    enabled: true
  client:
    config:
      default:
        connectTimeout: 3000
        readTimeout: 5000

@FeignClient

@FeignClient(name = "dictionaryService", path = "internal/metrics", url = "${host}", decode404 = true, configuration = {ResponseDecoder.class}, fallback = DictionaryServiceFallback.class)
public interface DictionaryService {

    @PostMapping("dictionary/getValueByPathKey")
    String getValueByPathKey(@RequestParam("path") String path, @RequestParam("key") String key);
}

@Service

@Slf4j
@Service
public class RsaServiceImpl implements RsaEncService {

    @Autowired
    private DictionaryService dictionaryService;

    private static String PUBLIC_KEY = null;

    private static String PRIVATE_KEY = null;

    private static final String XAPI_TOKEN = "xapi.token";

    @PostConstruct
    public void initKey() {
        PUBLIC_KEY = getPublicKey();
        PRIVATE_KEY = getPrivateKey();
    }

    @Override
    public String getPublicKey() {
        String value = dictionaryService.getValueByPathKey(XAPI_TOKEN, "public_key");
        if (StringUtils.isBlank(value)) {
            log.error("PublicKey获取失败");
        }
        return value;
    }

    @Override
    public String getPrivateKey() {
        String value = dictionaryService.getValueByPathKey(XAPI_TOKEN, "private_key");
        if (StringUtils.isBlank(value)) {
            log.error("PrivateKey获取失败");
        }
        return value;
    }

FallBack

@Slf4j
@Component
public class DictionaryServiceFallback implements DictionaryService {

    @Override
    public String getValueByPathKey(String path, String key) {
        log.error("获取字典失败 , path : {}, key : {}", path, key);
        return null;
    }
}

原因分析#

怀疑是在@Service的Bean创建后，@PostConstruct方法调用时，还没有加载Hystrix的配置，所以Hystrix使用的默认配置(默认timeoutInMilliseconds为1s)
debug到HystrixCommandProperties，发现没有加载到Hystrix的配置。而实际Hystrix配置应该通过ArchaiusAutoConfiguration中的Bean：ConfigurableEnvironmentConfiguration负责加载
@FeignClient是通过@EnableFeignClients注解扫描组装Bean得到的，HystrixCommand是在使用@FeignClient时才创建，通过feign.hystrix.HystrixInvocationHandler#invoke方法
在com.netflix.config.DynamicProperty#DynamicProperty(java.lang.String)构造函数中从ConcurrentCompositeConfiguration对象获取配置

解决#

使用@DependsOn("configurableEnvironmentConfiguration")注解

单独控制可以加在@Service注解上

@DependsOn("configurableEnvironmentConfiguration")
@Slf4j
@Service
public class RsaServiceImpl implements RsaEncService {
    ......
}

全局控制加在Application启动类上

@DependsOn("configurableEnvironmentConfiguration")
@SpringBootApplication
public class DevApplication{
    ......
}

总结#

HystrixCommand是在首次调用@FeignClient才初始化，所以需要确定Hystrix的配置此时是否已经加载到
Hystrix的配置默认是通过ArchaiusAutoConfiguration中的Bean--ConfigurableEnvironmentConfiguration负责加载
确保在使用@FeignClient时ConfigurableEnvironmentConfiguration已经被加载