protected void handleException(ZuulMessage zuulMesg, String filterName, Exception ex) {
        HttpRequestInfo zuulReq = null;
        if (zuulMesg instanceof HttpRequestMessage) {
            zuulReq = (HttpRequestMessage) zuulMesg;
        } else if (zuulMesg instanceof HttpResponseMessage) {
            zuulReq = ((HttpResponseMessage) zuulMesg).getInboundRequest();
        }
        String path = (zuulReq != null) ? zuulReq.getPathAndQuery() : "-";
        String method = (zuulReq != null) ? zuulReq.getMethod() : "-";
        String errMesg = "Error with filter: " + filterName + ", path: " + path + ", method: " + method;
        logger.error(errMesg, ex);
        getChannelHandlerContext(zuulMesg).fireExceptionCaught(ex);
    }
This is typically set by a filter when wanting to reject a request and also reduce load on the server by
 not processing anymore filterChain
zuul-core/src/main/java/com/netflix/zuul/netty/filter/BaseZuulFilterRunner.java