500 ZuulException: Forwarding error

　　 

com.netflix.zuul.exception.ZuulException: Forwarding error
    at org.springframework.cloud.netflix.zuul.filters.route.RibbonRoutingFilter.handleException(RibbonRoutingFilter.java:189) ~[spring-cloud-netflix-zuul-2.0.0.RELEASE.jar:2.0.0.RELEASE]
    at org.springframework.cloud.netflix.zuul.filters.route.RibbonRoutingFilter.forward(RibbonRoutingFilter.java:164) ~[spring-cloud-netflix-zuul-2.0.0.RELEASE.jar:2.0.0.RELEASE]
    at org.springframework.cloud.netflix.zuul.filters.route.RibbonRoutingFilter.run(RibbonRoutingFilter.java:112) ~[spring-cloud-netflix-zuul-2.0.0.RELEASE.jar:2.0.0.RELEASE]
    at com.netflix.zuul.ZuulFilter.runFilter(ZuulFilter.java:117) ~[zuul-core-1.3.1.jar:1.3.1]
    at com.netflix.zuul.FilterProcessor.processZuulFilter(FilterProcessor.java:193) ~[zuul-core-1.3.1.jar:1.3.1]
    at com.netflix.zuul.FilterProcessor.runFilters(FilterProcessor.java:157) ~[zuul-core-1.3.1.jar:1.3.1]
    at com.netflix.zuul.FilterProcessor.route(FilterProcessor.java:118) ~[zuul-core-1.3.1.jar:1.3.1]
    at com.netflix.zuul.ZuulRunner.route(ZuulRunner.java:96) ~[zuul-core-1.3.1.jar:1.3.1]
    at com.netflix.zuul.http.ZuulServlet.route(ZuulServlet.java:116) ~[zuul-core-1.3.1.jar:1.3.1]
    at com.netflix.zuul.http.ZuulServlet.service(ZuulServlet.java:81) ~[zuul-core-1.3.1.jar:1.3.1]
    at org.springframework.web.servlet.mvc.ServletWrappingController.handleRequestInternal(ServletWrappingController.java:165) [spring-webmvc-5.0.7.RELEASE.jar:5.0.7.RELEASE]

超时配置：

zuul:
  routes:
    api-a:
      path: /api-codes/**
      serviceId: INDEX-CODES-SERVIC
  host:
    max-total-connections: 10000
    max-per-route-connections: 10000
  semaphore:
    max-semaphores: 200