feign zipkin Trace Hystrix 重试源码详解

我就是我 2022-10-02 03:50 170阅读 0赞

[2019独角兽企业重金招聘Python工程师标准>>> ][2019_Python_] ![hot3.png][]

feign zipkin Trace Hystrix 重试源码详解
    
    @Configuration
    @ConditionalOnProperty(value = "spring.sleuth.enabled", havingValue = "true")
    @Slf4j
    public class CommonTraceHystrixConfiguration {
    
    	/**
    	 * hystrix 超时时间
    	 */
    	static int hystrixTimeOut = 5000;
    	/**
    	 * 请求超时时间
    	 */
    	static int requestTimeOut = 4000;
    
    	@Bean
    	public Request.Options options() {
    		return new Request.Options(requestTimeOut, requestTimeOut);
    	}
    
    	@Bean
    	Retryer feignRetryer() {
    		//最多访问一次
    		return new Retryer.Default(100, SECONDS.toMillis(1), 1);
    	}
    
    	@Bean
    	@Primary
    	@Scope("prototype")
    	public Feign.Builder feignTraceHystrixBuilderExt(BeanFactory beanFactory) {
    		return HystrixFeign.builder().setterFactory(new SetterFactory() {
    			public HystrixCommand.Setter create(Target<?> target, Method method) {
    				String groupKey = target.name();
    				String commandKey = method.getName();
    				return HystrixCommand.Setter.withGroupKey(HystrixCommandGroupKey.Factory.asKey(groupKey))
    						.andCommandKey(HystrixCommandKey.Factory.asKey(commandKey)).andCommandPropertiesDefaults(
    								HystrixCommandProperties.Setter().withExecutionTimeoutInMilliseconds(hystrixTimeOut)
    										.withCircuitBreakerSleepWindowInMilliseconds(hystrixTimeOut));
    			}
    		}).client(new TraceFeignClient(beanFactory));//TraceFeignClient 是client得一个子类
    	}
    
    }
    
    org.springframework.cloud.sleuth.instrument.web.client.feign.TraceFeignClient.execute(Request, Options)
    @Override
    	public Response execute(Request request, Request.Options options) throws IOException {
    		String spanName = getSpanName(request);
    		Span span = getTracer().createSpan(spanName);
    		if (log.isDebugEnabled()) {
    			log.debug("Created new Feign span " + span);
    		}
    		try {
    			AtomicReference<Request> feignRequest = new AtomicReference<>(request);
    			this.spanInjector.inject(span, feignRequest);
    			span.logEvent(Span.CLIENT_SEND);
    			addRequestTags(request);
    			Request modifiedRequest = feignRequest.get();
    			if (log.isDebugEnabled()) {
    				log.debug("The modified request equals " + modifiedRequest);
    			}
    			Response response = this.delegate.execute(modifiedRequest, options);
    			logCr();
    			return response;
    		} catch (RuntimeException | IOException e) {
    			logError(e);
    			throw e;
    		} finally {
    			closeSpan(span);
    		}
    	}
    
    
    
    feign.SynchronousMethodHandler.invoke(Object[])
    
    
     @Override
      public Object invoke(Object[] argv) throws Throwable {
        RequestTemplate template = buildTemplateFromArgs.create(argv);
        Retryer retryer = this.retryer.clone();
        while (true) {
          try {
            return executeAndDecode(template);//这里会调用TraceFeignClient 
          } catch (RetryableException e) {
            retryer.continueOrPropagate(e);//判断最大重试次输
            if (logLevel != Logger.Level.NONE) {
              logger.logRetry(metadata.configKey(), logLevel);
            }
            continue;
          }
        }
      }
    
    
    
    
    
    
    public interface Retryer extends Cloneable {
    
      /**
       * if retry is permitted, return (possibly after sleeping). Otherwise propagate the exception.
       */
      void continueOrPropagate(RetryableException e);
    
      Retryer clone();
    
      public static class Default implements Retryer {
    
        private final int maxAttempts;
        private final long period;
        private final long maxPeriod;
        int attempt;//当前访问次数
        long sleptForMillis;
    
        public Default() {
          this(100, SECONDS.toMillis(1), 5);
        }
    
        public Default(long period, long maxPeriod, int maxAttempts) {
          this.period = period;
          this.maxPeriod = maxPeriod;
          this.maxAttempts = maxAttempts;//最大访问次输
          this.attempt = 1;//当前访问次数
        }
    
        // visible for testing;
        protected long currentTimeMillis() {
          return System.currentTimeMillis();
        }
    
        public void continueOrPropagate(RetryableException e) {
          if (attempt++ >= maxAttempts) {
            throw e;
          }
    
          long interval;
          if (e.retryAfter() != null) {
            interval = e.retryAfter().getTime() - currentTimeMillis();
            if (interval > maxPeriod) {
              interval = maxPeriod;
            }
            if (interval < 0) {
              return;
            }
          } else {
            interval = nextMaxInterval();
          }
          try {
            Thread.sleep(interval);
          } catch (InterruptedException ignored) {
            Thread.currentThread().interrupt();
          }
          sleptForMillis += interval;
        }
    
        /**
         * Calculates the time interval to a retry attempt. <br> The interval increases exponentially
         * with each attempt, at a rate of nextInterval *= 1.5 (where 1.5 is the backoff factor), to the
         * maximum interval.
         *
         * @return time in nanoseconds from now until the next attempt.
         */
        long nextMaxInterval() {
          long interval = (long) (period * Math.pow(1.5, attempt - 1));
          return interval > maxPeriod ? maxPeriod : interval;
        }
    
        @Override
        public Retryer clone() {
          return new Default(period, maxPeriod, maxAttempts);
        }
      }
    
      /**
       * Implementation that never retries request. It propagates the RetryableException.
       */
      Retryer NEVER_RETRY = new Retryer() {
    
        @Override
        public void continueOrPropagate(RetryableException e) {
          throw e;
        }
    
        @Override
        public Retryer clone() {
          return this;
        }
      };
    }

转载于:https://my.oschina.net/xiaominmin/blog/3049830

[2019_Python_]: https://my.oschina.net/u/2663968/blog/3061697
[hot3.png]: /images/20220113/1e081b4aa1eb433aadda847319d44e75.png