浅析SpringBoot单体应用熔断技术的使用

  com.alibaba.cloud
  spring-cloud-starter-alibaba-sentinel
  2.0.3.RELEASE

@Target({ElementType.METHOD, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Inherited
public @interface SentinelResource {
  //资源名称
  String value() default "";
 
  //流量方向
  EntryType entryType() default EntryType.OUT;
 
  //资源类型
  int resourceType() default 0;
 
  //异常处理方法
  String blockHandler() default "";
 
  //异常处理类
  Class<&＃63;>[] blockHandlerClass() default {};
 
  //熔断方法
  String fallback() default "";
 
  //默认熔断方法
  String defaultFallback() default "";
 
  //熔断类
  Class<&＃63;>[] fallbackClass() default {};
 
  //统计异常
  Class<&＃63; extends Throwable>[] exceptionsToTrace() default {Throwable.class};
 
  //忽略异常
  Class<&＃63; extends Throwable>[] exceptionsToIgnore() default {};
}

@RequestMapping("/get")
@ResponseBody
@SentinelResource(value = "allInfos",fallback = "errorReturn")
public JsonResult allInfos(HttpServletRequest request, HttpServletResponse response, @RequestParam Integer num){
    try {
      if (num % 2 == 0) {
        log.info("num % 2 == 0");
        throw new BaseException("something bad with 2", 400);
      }
      return JsonResult.ok();
    } catch (ProgramException e) {
      log.info("error");
      return JsonResult.error("error");
    }
  }

/**
   * 限流，参数需要和方法保持一致
   * @param request
   * @param response
   * @param num
   * @return
   * @throws BlockException
   */
  public JsonResult errorReturn(HttpServletRequest request, HttpServletResponse response, @RequestParam Integer num) throws BlockException {
    return JsonResult.error("error 限流" + num );
  }
 
  /**
   * 熔断，参数需要和方法保持一直，并且需要添加BlockException异常
   * @param request
   * @param response
   * @param num
   * @param b
   * @return
   * @throws BlockException
   */
  public JsonResult errorReturn(HttpServletRequest request, HttpServletResponse response, @RequestParam Integer num,BlockException b) throws BlockException {
    return JsonResult.error("error 熔断" + num );
  }

spring:
 cloud:
  sentinel:
   transport:
    port: 8719
    dashboard: localhost:8080

  org.springframework.boot
  spring-boot-starter-actuator


  org.springframework.cloud
  spring-cloud-starter-netflix-hystrix-dashboard
  2.0.4.RELEASE


  org.springframework.cloud
  spring-cloud-starter-netflix-hystrix
  2.0.4.RELEASE

@Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Inherited
@Documented
public @interface HystrixCommand {
  String groupKey() default "";
 
  String commandKey() default "";
 
  String threadPoolKey() default "";
 
  String fallbackMethod() default "";
 
  HystrixProperty[] commandProperties() default {};
 
  HystrixProperty[] threadPoolProperties() default {};
 
  Class<&＃63; extends Throwable>[] ignoreExceptions() default {};
 
  ObservableExecutionMode observableExecutionMode() default ObservableExecutionMode.EAGER;
 
  HystrixException[] raiseHystrixExceptions() default {};
 
  String defaultFallback() default "";
}

@RequestMapping("/get")
@ResponseBody
@HystrixCommand(fallbackMethod = "fallbackMethod")
public JsonResult allInfos(HttpServletRequest request, HttpServletResponse response, @RequestParam Integer num){
  try {
    if (num % 3 == 0) {
      log.info("num % 3 == 0");
      throw new BaseException("something bad whitch 3", 400);
    }
 
    return JsonResult.ok();
  } catch (ProgramException | InterruptedException exception) {
    log.info("error");
    return JsonResult.error("error");
  }
}

/**
 * 该方法是熔断回调方法，参数需要和接口保持一致
 * @param request
 * @param response
 * @param num
 * @return
 */
public JsonResult fallbackMethod(HttpServletRequest request, HttpServletResponse response, @RequestParam Integer num) {
  response.setStatus(500);
  log.info("发生了熔断！！");
  return JsonResult.error("熔断");
}

hystrix:
 command:
  default:
   execution:
    isolation:
     strategy: THREAD
     thread:
      # 线程超时15秒,调用Fallback方法
      timeoutInMilliseconds: 15000
   metrics:
    rollingStats:
     timeInMilliseconds: 15000
   circuitBreaker:
    # 10秒内出现3个以上请求(已临近阀值),并且出错率在50%以上,开启断路器.断开服务,调用Fallback方法
    requestVolumeThreshold: 3
    sleepWindowInMilliseconds: 10000

dependency>
  org.springframework.boot
  spring-boot-starter-web

 

  org.springframework.boot
  spring-boot-starter-test
  test

 

  io.github.resilience4j
  resilience4j-spring-boot2
  1.6.1

 

  io.github.resilience4j
  resilience4j-bulkhead
  1.6.1

 

  io.github.resilience4j
  resilience4j-ratelimiter
  1.6.1

 

  io.github.resilience4j
  resilience4j-timelimiter
  1.6.1

@RequestMapping("/get")
@ResponseBody
//@TimeLimiter(name = "BulkheadA",fallbackMethod = "fallbackMethod")
@CircuitBreaker(name = "BulkheadA",fallbackMethod = "fallbackMethod")
@Bulkhead(name = "BulkheadA",fallbackMethod = "fallbackMethod")
public JsonResult allInfos(HttpServletRequest request, HttpServletResponse response, @RequestParam Integer num){
  log.info("param----->" + num);
  try {
    //Thread.sleep(num);
 
    if (num % 2 == 0) {
      log.info("num % 2 == 0");
      throw new BaseException("something bad with 2", 400);
    }
 
    if (num % 3 == 0) {
      log.info("num % 3 == 0");
      throw new BaseException("something bad whitch 3", 400);
    }
 
    if (num % 5 == 0) {
      log.info("num % 5 == 0");
      throw new ProgramException("something bad whitch 5", 400);
    }
    if (num % 7 == 0) {
      log.info("num % 7 == 0");
      int res = 1 / 0;
    }
    return JsonResult.ok();
  } catch (BufferUnderflowException e) {
    log.info("error");
    return JsonResult.error("error");
  }
}

/**
 * 需要参数一致，并且加上相应异常
 * @param request
 * @param response
 * @param num
 * @param exception
 * @return
 */
public JsonResult fallbackMethod(HttpServletRequest request, HttpServletResponse response, @RequestParam Integer num, BulkheadFullException exception) {
  return JsonResult.error("error 熔断" + num );
}

resilience4j.circuitbreaker:
  instances:
    backendA:
      registerHealthIndicator: true
      slidingWindowSize: 100
    backendB:
      registerHealthIndicator: true
      slidingWindowSize: 10
      permittedNumberOfCallsInHalfOpenState: 3
      slidingWindowType: TIME_BASED
      minimumNumberOfCalls: 20
      waitDurationInOpenState: 50s
      failureRateThreshold: 50
      eventConsumerBufferSize: 10
      recordFailurePredicate: io.github.robwin.exception.RecordFailurePredicate
 
resilience4j.retry:
  instances:
    backendA:
      maxRetryAttempts: 3
      waitDuration: 10s
      enableExponentialBackoff: true
      exponentialBackoffMultiplier: 2
      retryExceptions:
        - org.springframework.web.client.HttpServerErrorException
        - java.io.IOException
      ignoreExceptions:
        - io.github.robwin.exception.BusinessException
    backendB:
      maxRetryAttempts: 3
      waitDuration: 10s
      retryExceptions:
        - org.springframework.web.client.HttpServerErrorException
        - java.io.IOException
      ignoreExceptions:
        - io.github.robwin.exception.BusinessException
 
resilience4j.bulkhead:
  instances:
    backendA:
      maxConcurrentCalls: 10
    backendB:
      maxWaitDuration: 10ms
      maxConcurrentCalls: 20
 
resilience4j.thread-pool-bulkhead:
 instances:
  backendC:
   maxThreadPoolSize: 1
   coreThreadPoolSize: 1
   queueCapacity: 1
 
resilience4j.ratelimiter:
  instances:
    backendA:
      limitForPeriod: 10
      limitRefreshPeriod: 1s
      timeoutDuration: 0
      registerHealthIndicator: true
      eventConsumerBufferSize: 100
    backendB:
      limitForPeriod: 6
      limitRefreshPeriod: 500ms
      timeoutDuration: 3s
 
resilience4j.timelimiter:
  instances:
    backendA:
      timeoutDuration: 2s
      cancelRunningFuture: true
    backendB:
      timeoutDuration: 1s
      cancelRunningFuture: false