微服务 spring cloud zuul com.netflix.zuul.exception.ZuulException GENERAL

1.背景

错误信息：

-- [http-nio-9904-exec-5] o.s.c.n.z.filters.post.SendErrorFilter   : Error during filtering


com.netflix.zuul.exception.ZuulException: Forwarding error
        at org.springframework.cloud.netflix.zuul.filters.route.RibbonRoutingFilter.handleException(RibbonRoutingFilter.java:183)
        at org.springframework.cloud.netflix.zuul.filters.route.RibbonRoutingFilter.forward(RibbonRoutingFilter.java:158)
        at org.springframework.cloud.netflix.zuul.filters.route.RibbonRoutingFilter.run(RibbonRoutingFilter.java:106)
        at com.netflix.zuul.ZuulFilter.runFilter(ZuulFilter.java:112)
        at com.netflix.zuul.FilterProcessor.processZuulFilter(FilterProcessor.java:193)
        at com.netflix.zuul.FilterProcessor.runFilters(FilterProcessor.java:157)
        at com.netflix.zuul.FilterProcessor.route(FilterProcessor.java:118)
        at com.netflix.zuul.ZuulRunner.route(ZuulRunner.java:96)
        at com.netflix.zuul.http.ZuulServlet.route(ZuulServlet.java:116)
        at com.netflix.zuul.http.ZuulServlet.service(ZuulServlet.java:81)
        at org.springframework.web.servlet.mvc.ServletWrappingController.handleRequestInternal(ServletWrappingController.java:157)
        at org.springframework.cloud.netflix.zuul.web.ZuulController.handleRequest(ZuulController.java:44)
        at org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter.handle(SimpleControllerHandlerAdapter.java:50)
        at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963)
        at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897)
        at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
        at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:635)
        at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
        at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
        at org.springframework.boot.web.filter.ApplicationContextHeaderFilter.doFilterInternal(ApplicationContextHeaderFilter.java:55)
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
        at org.springframework.boot.actuate.trace.WebRequestTraceFilter.doFilterInternal(WebRequestTraceFilter.java:110)
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
        at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
        at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:105)
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
        at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:81)
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
        at org.springframework.cloud.sleuth.instrument.web.TraceFilter.doFilter(TraceFilter.java:169)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
2018-01-18 09:48:18.852 ERROR [api-gateway,5047c7e7b4449179,aa1e88c3768befe6,true] 1 --- [http-nio-9904-exec-5] c.r.k.api.gateway.filter.AccessFilter    : 错误信息:{timestamp=Thu Jan 18 09:48:18 UTC 2018, status=500, error=Internal Server Error, exception=com.netflix.zuul.exception.ZuulException, message=GENERAL}
2018-01-18 09:48:18.855  INFO [服务名,5047c7e7b4449179,5047c7e7b4449179,true] 1 --- [http-nio-9904-exec-5] c.r.k.api.gateway.filter.ResponseFilter  : 请求耗时:5016毫秒

2.场景分析

根据日志信息进行回溯问题的发生点；

at org.springframework.cloud.netflix.zuul.filters.route.RibbonRoutingFilter.handleException(RibbonRoutingFilter.java:183)根据 这段日志我们找到如下源码：

 

package org.springframework.cloud.netflix.zuul.filters.route

public class RibbonRoutingFilter extends ZuulFilter

 

 

protected ClientHttpResponse handleException(Map info,
      HystrixRuntimeException ex) throws ZuulException {
   int statusCode = HttpStatus.INTERNAL_SERVER_ERROR.value();
   Throwable cause = ex;
   String message = ex.getFailureType().toString();

   ClientException clientException = findClientException(ex);
   if (clientException == null) {
      clientException = findClientException(ex.getFallbackException());
   }

   if (clientException != null) {
      if (clientException
            .getErrorType() == ClientException.ErrorType.SERVER_THROTTLED) {
         statusCode = HttpStatus.SERVICE_UNAVAILABLE.value();
      }
      cause = clientException;
      message = clientException.getErrorType().toString();
   }
   info.put("status", String.valueOf(statusCode));
   throw new ZuulException(cause, "Forwarding error", statusCode, message);
}

分析如上函数handleException（... ...）执行逻辑；重点是最后一行代码，throw new ZuulException(cause,"Forwarding error",statusCode,message);接下来我们逐个分析各个变量是如何被赋值的；

 

1） 其中变量statusCode赋值有两种情况，一种为初始被赋值为HttpStatus.INTERNAL_SERVER_ERROR.value()（值：500）；另一种情况被赋值为HttpStatus.SERVICE_UNAVAILABLE.value()（值：503）；

 

HttpStatus.INTERNAL_SERVER_ERROR.value()

/**
 * {@code 500 Internal Server Error}.
 * @see HTTP/1.1: Semantics and Content, section 6.6.1
 */
INTERNAL_SERVER_ERROR(500, "Internal Server Error"),

 

HttpStatus.SERVICE_UNAVAILABLE.value()

 

 

 

/**
 * {@code 503 Service Unavailable}.
 * @see HTTP/1.1: Semantics and Content, section 6.6.4
 */
SERVICE_UNAVAILABLE(503, "Service Unavailable"),

由于最终new ZuulExceptioin的statusCode为500，所以可以排除SERVER_UNAVAILABLE的情况；

 

2） 变量message的赋值也有两种情况：一种如初始赋值String message = ex.getFailureType().toString();（HystrixRuntimeException）；另一种是message = clientException.getErrorType().toString();（ClientException）；

下面分别为HystrixRuntimeException 的FailureType的类型信息，ClientException的ErrorType类型信息：

 

public static enum FailureType {
    BAD_REQUEST_EXCEPTION, COMMAND_EXCEPTION, TIMEOUT, SHORTCIRCUIT, REJECTED_THREAD_EXECUTION, REJECTED_SEMAPHORE_EXECUTION, REJECTED_SEMAPHORE_FALLBACK
}

/**
    * define your error codes here
    * 
    */
   public enum ErrorType{
       GENERAL, 
       CONFIGURATION, 
       NUMBEROF_RETRIES_EXEEDED, 
       NUMBEROF_RETRIES_NEXTSERVER_EXCEEDED, 
       SOCKET_TIMEOUT_EXCEPTION, 
       READ_TIMEOUT_EXCEPTION,
       UNKNOWN_HOST_EXCEPTION,
       CONNECT_EXCEPTION,
       CLIENT_THROTTLED,
       SERVER_THROTTLED,
       NO_ROUTE_TO_HOST_EXCEPTION,
       CACHE_MISSING;
       
       static String getName(int errorCode){
           if (ErrorType.values().length >= errorCode){
               return ErrorType.values()[errorCode].name();
           }else{
               return "UNKNOWN ERROR CODE";
           }
       }
   }

而最终message=GENERAL ，排除了初始赋值，异常由ClientException产生；

解决思路：

    关于上面