HDFS-12339. NFS Gateway on Shutdown Gives Unregistration Failure. Does Not Unregister with rpcbind Portmapper. Contributed by Mukul Kumar Singh.

hadoop-common-project/hadoop-nfs/src/main/java/org/apache/hadoop/mount/MountdBase.java

@@ -109,6 +109,17 @@ abstract public class MountdBase {
     }
   }
 
+  public void stop() {
+    if (udpBoundPort > 0) {
+      rpcProgram.unregister(PortmapMapping.TRANSPORT_UDP, udpBoundPort);
+      udpBoundPort = 0;
+    }
+    if (tcpBoundPort > 0) {
+      rpcProgram.unregister(PortmapMapping.TRANSPORT_TCP, tcpBoundPort);
+      tcpBoundPort = 0;
+    }
+  }
+
   /**
    * Priority of the mountd shutdown hook.
    */
@@ -117,8 +128,7 @@ abstract public class MountdBase {
   private class Unregister implements Runnable {
     @Override
     public synchronized void run() {
-      rpcProgram.unregister(PortmapMapping.TRANSPORT_UDP, udpBoundPort);
-      rpcProgram.unregister(PortmapMapping.TRANSPORT_TCP, tcpBoundPort);
+      stop();
     }
   }
 

hadoop-common-project/hadoop-nfs/src/main/java/org/apache/hadoop/nfs/nfs3/Nfs3Base.java

@@ -78,6 +78,13 @@ public abstract class Nfs3Base {
     nfsBoundPort = tcpServer.getBoundPort();
   }
 
+  public void stop() {
+    if (nfsBoundPort > 0) {
+      rpcProgram.unregister(PortmapMapping.TRANSPORT_TCP, nfsBoundPort);
+      nfsBoundPort = 0;
+    }
+    rpcProgram.stopDaemons();
+  }
   /**
    * Priority of the nfsd shutdown hook.
    */
@@ -86,8 +93,7 @@ public abstract class Nfs3Base {
   private class NfsShutdownHook implements Runnable {
     @Override
     public synchronized void run() {
-      rpcProgram.unregister(PortmapMapping.TRANSPORT_TCP, nfsBoundPort);
-      rpcProgram.stopDaemons();
+      stop();
     }
   }
 }

hadoop-hdfs-project/hadoop-hdfs-nfs/src/main/java/org/apache/hadoop/hdfs/nfs/nfs3/Nfs3.java

@@ -57,7 +57,7 @@ public class Nfs3 extends Nfs3Base {
     start(register);
   }
   
-  static void startService(String[] args,
+  static Nfs3 startService(String[] args,
       DatagramSocket registrationSocket) throws IOException {
     StringUtils.startupShutdownMessage(Nfs3.class, args, LOG);
     NfsConfiguration conf = new NfsConfiguration();
@@ -67,8 +67,14 @@ public class Nfs3 extends Nfs3Base {
     final Nfs3 nfsServer = new Nfs3(conf, registrationSocket,
         allowInsecurePorts);
     nfsServer.startServiceInternal(true);
+    return nfsServer;
   }
-  
+
+  public void stop() {
+    super.stop();
+    mountd.stop();
+  }
+
   public static void main(String[] args) throws IOException {
     startService(args, null);
   }

hadoop-hdfs-project/hadoop-hdfs-nfs/src/main/java/org/apache/hadoop/hdfs/nfs/nfs3/PrivilegedNfsGatewayStarter.java

@@ -40,6 +40,7 @@ public class PrivilegedNfsGatewayStarter implements Daemon {
   static final Log LOG = LogFactory.getLog(PrivilegedNfsGatewayStarter.class);
   private String[] args = null;
   private DatagramSocket registrationSocket = null;
+  private Nfs3 nfs3Server = null;
 
   @Override
   public void init(DaemonContext context) throws Exception {
@@ -68,12 +69,14 @@ public class PrivilegedNfsGatewayStarter implements Daemon {
 
   @Override
   public void start() throws Exception {
-    Nfs3.startService(args, registrationSocket);
+    nfs3Server = Nfs3.startService(args, registrationSocket);
   }
 
   @Override
   public void stop() throws Exception {
-    // Nothing to do.
+    if (nfs3Server != null) {
+      nfs3Server.stop();
+    }
   }
 
   @Override