HDFS-11479. Socket re-use address option should be used in SimpleUdpServer. Contributed by Mukul Kumar Singh.

hadoop-common-project/hadoop-nfs/src/main/java/org/apache/hadoop/oncrpc/SimpleUdpServer.java

@@ -63,6 +63,7 @@ public class SimpleUdpServer {
     server.setOption("broadcast", "false");
     server.setOption("sendBufferSize", SEND_BUFFER_SIZE);
     server.setOption("receiveBufferSize", RECEIVE_BUFFER_SIZE);
+    server.setOption("reuseAddress", true);
 
     // Listen to the UDP port
     ch = server.bind(new InetSocketAddress(port));