如何使用 netflix hystrix 获取断路器状态的状态？

Posted 2023-03-16

【中文标题】如何使用 netflix hystrix 获取断路器状态的状态？

【英文标题】：How to get status for circuit breaker status with netflix hystrix?

【发布时间】：2021-01-17 23:20:55

【问题描述】：

这是我的 AppService 类，我需要在其中添加逻辑以获取断路器的状态（如果它是打开或关闭的），但我找不到方法。另外，我使用了ignoreExceptions，但似乎有麻烦。刚接触编码和此功能，无法获得适当的答案。我不知道如何使用 isCircuitBreakerOpen()。

@Service
public class AppService 

    private static final Logger LOG = LoggerFactory.getLogger(AppService.class);
    private final RestTemplate restTemplate;

    public AppService(RestTemplate rest) 
        this.restTemplate = rest;
    
    
    
    
    @HystrixCommand(fallbackMethod = "reliable", commandProperties= 
            @HystrixProperty(name = HystrixPropertiesManager.CIRCUIT_BREAKER_ERROR_THRESHOLD_PERCENTAGE, value = "100"),
            @HystrixProperty(name = HystrixPropertiesManager.CIRCUIT_BREAKER_SLEEP_WINDOW_IN_MILLISECONDS, value = "10000"),
            @HystrixProperty(name = HystrixPropertiesManager.CIRCUIT_BREAKER_REQUEST_VOLUME_THRESHOLD, value = "10")
            )
            public ResponseEntity<String> answerList() throws Exception 
                return callingDownStreamService404();
                

    @HystrixCommand(fallbackMethod = "reliable", commandProperties= 
            @HystrixProperty(name = HystrixPropertiesManager.CIRCUIT_BREAKER_ERROR_THRESHOLD_PERCENTAGE, value = "100"),
            @HystrixProperty(name = HystrixPropertiesManager.CIRCUIT_BREAKER_SLEEP_WINDOW_IN_MILLISECONDS, value = "10000"),
            @HystrixProperty(name = HystrixPropertiesManager.CIRCUIT_BREAKER_REQUEST_VOLUME_THRESHOLD, value = "10")
        )
    public ResponseEntity<String> answerList503() throws Exception 
                return callingDownStreamService503();
                
    
    
                private ResponseEntity<String> callingDownStreamService404() throws Exception 
                    URI uri = URI.create("http://localhost:8090/recommended/404");

                    RestTemplate restTemplate = new RestTemplate();
                    HttpHeaders headers = new HttpHeaders();
                    HttpEntity<Object> entity = new HttpEntity<Object>(headers);

                    ResponseEntity<String> out = restTemplate.exchange(uri, HttpMethod.GET, entity, String.class);
                    System.out.println("Application code : " + out.getStatusCode());
                    return out;

                

                private ResponseEntity<String> callingDownStreamService503() throws Exception 
                    URI uri = URI.create("http://localhost:8090/recommended/503");

                    RestTemplate restTemplate = new RestTemplate();
                    HttpHeaders headers = new HttpHeaders();
                    HttpEntity<Object> entity = new HttpEntity<Object>(headers);

                    ResponseEntity<String> out = restTemplate.exchange(uri, HttpMethod.GET, entity, String.class);
                    System.out.println("Application code : " + out.getStatusCode());

                    if (out.getStatusCode().toString().startsWith("5")) 
                        throw new HystrixBadRequestException("bad request messageg");
                    

                    return out;

                

                @HystrixCommand(commandKey = "MyHystrixCommand",fallbackMethod = "myHystrixFallback", threadPoolKey = "ThreadPoolKey",commandProperties= 
                      @HystrixProperty(name = HystrixPropertiesManager.CIRCUIT_BREAKER_ERROR_THRESHOLD_PERCENTAGE, value = "100"),
                      @HystrixProperty(name = HystrixPropertiesManager.CIRCUIT_BREAKER_SLEEP_WINDOW_IN_MILLISECONDS, value = "10000"),
                      @HystrixProperty(name = HystrixPropertiesManager.CIRCUIT_BREAKER_REQUEST_VOLUME_THRESHOLD, value = "10"),
                    ignoreExceptions = HttpServerErrorException.class, HystrixBadRequestException.class, HttpClientErrorException.class)
                
                public ResponseEntity<String> getServiceCallResponse(String serviceUrl, HttpEntity<?> entity) 
                     serviceUrl = "http://localhost:8090/recommended/500";
                    
                    ResponseEntity<String> resp = null;
                    
                    try 
                        System.out.println("Calling -----" + serviceUrl);
                        resp = restTemplate.exchange(serviceUrl, HttpMethod.POST, entity, String.class);
                        
                        
                    catch(RestClientException e) 
                        System.out.println("Calling -----" + serviceUrl + "Exception is this" + e.getRootCause());
                        handleExceptionForHystrix("getServiceCallResponse", e);
                    
                    return resp;
                    

                    private void handleExceptionForHystrix(String function, Exception e) 
                            if (e instanceof HttpStatusCodeException) 
                                HttpStatus httpStatusCode = ((HttpStatusCodeException)e).getStatusCode();
                                if(httpStatusCode.equals(HttpStatus.BAD_REQUEST) || httpStatusCode.equals(HttpStatus.INTERNAL_SERVER_ERROR)) 
                                    throw new HystrixBadRequestException("Hystrix Bad Request Exception Occurred" + httpStatusCode, e);
                                
                                throw new RuntimeException(function, e);
                            
                            throw new RuntimeException(function, e);
                        


                    public ResponseEntity<String> myHystrixFallback(String serviceUrl, HttpEntity<?> entity, Throwable hystrixCommandExp) 
                        
                                return new ResponseEntity<String>(HttpStatus.INTERNAL_SERVER_ERROR);
                            
                
                @Recover()
                public ResponseEntity<String> reliable() 
                    return new ResponseEntity<String>(
                            "The downstream application is unavailable and the circuit is open", HttpStatus.OK);
                
                
                
            

这是我放置端点的主要类。我也在使用 AppStore，它是下游应用程序，并且在那里配置了相同的端点。

@EnableHystrixDashboard
@EnableCircuitBreaker
@RestController
@SpringBootApplication
public class DavinciCircuitbreakerApplication 
    
      @Autowired
      private AppService appService;
      
      @Bean
      public RestTemplate rest(RestTemplateBuilder builder) 
      return builder.build();
      

          
      @RequestMapping("/to-answer/404")
      public ResponseEntity<String> toAnswer() 
          ResponseEntity<String> response = null;
        try
            response = appService.answerList();
        catch(Exception e)
            System.out.println("excpetion"+ e.getMessage());
            return new ResponseEntity<String>("failure", HttpStatus.valueOf(500));
        


      return response;
      

    @RequestMapping("/to-answer/503")
    public ResponseEntity<String> toAnswer503() 
        ResponseEntity<String> response = null;
        try
            response = appService.answerList503();
        catch(Exception e)
            System.out.println("excpetion"+ e.getMessage());
            return new ResponseEntity<String>("failure", HttpStatus.valueOf(503));
        


        return response;
    
    
    @RequestMapping("/to-answer/500")
    public ResponseEntity<String> toAnswer500() 
        ResponseEntity<String> response = null;
        try
            response = appService.getServiceCallResponse(null, response);
        catch(Exception e)
            System.out.println("excpetion"+ e.getMessage());
            return new ResponseEntity<String>("Internal Server Error", HttpStatus.valueOf(500));
        


    return response;


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

【参考方案1】：

您可以使用HystrixCircuitBreaker.Factory.getInstance(...) 获取HystrixCommand 的实例。详情请参阅link。

您还可以在此 HystrixCommand 实例上调用 isCircuitBreakerOpen()。