1、udp handler出现大量的WARN io.netty.channel.DefaultChannelPipeline - An exceptionCaught() event was fired, and it reached at the tail of the pipeline. It usually means the last handler in the pipeline did not handle the exception.

java.io.IOException: 打开的文件过多
  在异常捕获中增加关闭context的处理

sec-beidou-rtcm/src/main/java/com/imdroid/sideslope/server/udp/RtcmUdpHandler.java

@@ -54,6 +54,7 @@ public class RtcmUdpHandler extends ChannelInboundHandlerAdapter {
     public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
         super.exceptionCaught(ctx, cause);
         logger.error("Exception caught: {}", cause.toString());
+        ctx.close();
     }
 
 }