@Override
        public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
            if (evt instanceof HttpLifecycleChannelHandler.StartEvent) {
                incrementCurrentRequestsInFlight(ctx);
            } else if (evt instanceof HttpLifecycleChannelHandler.CompleteEvent) {
                decrementCurrentRequestsIfOneInflight(ctx);
            }

            super.userEventTriggered(ctx, evt);
        }
User: michaels@netflix.com
Date: 2/6/17
Time: 2:21 PM
zuul-core/src/main/java/com/netflix/netty/common/metrics/PerEventLoopMetricsChannelHandler.java