HDFS-4084. Provide CLI support to allow and disallow snapshot on a directory. Contributed by Brondon Li.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/HDFS-2802@1401444 13f79535-47bb-0310-9956-ffa450edef68

hadoop-hdfs-project/hadoop-hdfs/CHANGES.HDFS-2802.txt

@@ -20,3 +20,6 @@ Branch-2802 Snapshot (Unreleased)
   directory to snapshottable and creating a snapshot.  (szetszwo)
 
   HDFS-4078. Handle replication in snapshots.  (szetszwo)
+
+  HDFS-4084. Provide CLI support to allow and disallow snapshot 
+  on a directory. (Brondon Li via suresh)

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSClient.java

@@ -1873,6 +1873,24 @@ public class DFSClient implements java.io.Closeable {
     return namenode.setSafeMode(action);
   }
 
+  /**
+   * Allow snapshot on a directory.
+   * 
+   * @see ClientProtocol#allowSnapshot(String snapshotRoot)
+   */
+  public void allowSnapshot(String snapshotRoot) throws IOException {
+    namenode.allowSnapshot(snapshotRoot);
+  }
+  
+  /**
+   * Disallow snapshot on a directory.
+   * 
+   * @see ClientProtocol#disallowSnapshot(String snapshotRoot)
+   */
+  public void disallowSnapshot(String snapshotRoot) throws IOException {
+    namenode.disallowSnapshot(snapshotRoot);
+  }
+  
   /**
    * Save namespace image.
    * 

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DistributedFileSystem.java

@@ -868,4 +868,26 @@ public class DistributedFileSystem extends FileSystem {
   public boolean isInSafeMode() throws IOException {
     return setSafeMode(SafeModeAction.SAFEMODE_GET);
   }
+
+  /**
+   * Allow snapshot on a directory.
+   * 
+   * @param snapshotRoot the directory to be snapped
+   * @throws IOException
+   */
+  public void allowSnapshot(String snapshotRoot)
+      throws IOException {
+    dfs.allowSnapshot(snapshotRoot);
+  }
+  
+  /**
+   * Disallow snapshot on a directory.
+   * 
+   * @param snapshotRoot the directory to be snapped
+   * @throws IOException
+   */
+  public void disallowSnapshot(String snapshotRoot)
+      throws IOException {
+    dfs.disallowSnapshot(snapshotRoot);
+  }
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/ClientProtocol.java

@@ -972,5 +972,21 @@ public interface ClientProtocol {
    */
   public SnapshotInfo[] listSnapshots(String snapshotRoot)
       throws IOException;
+  
+    /**
+     * Allow snapshot on a directory.
+     * @param snapshotRoot the directory to be snapped
+     * @throws IOException
+     */
+  public void allowSnapshot(String snapshotRoot)
+      throws IOException;
+    
+    /**
+     * Disallow snapshot on a directory.
+     * @param snapshotRoot the directory to disallow snapshot
+     * @throws IOException
+     */
+  public void disallowSnapshot(String snapshotRoot)
+      throws IOException;   
 }
 

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/ClientNamenodeProtocolServerSideTranslatorPB.java

@@ -37,6 +37,8 @@ import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.Abando
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.AbandonBlockResponseProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.AddBlockRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.AddBlockResponseProto;
+import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.AllowSnapshotRequestProto;
+import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.AllowSnapshotResponseProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.AppendRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.AppendResponseProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.CancelDelegationTokenRequestProto;
@@ -55,6 +57,8 @@ import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.Delete
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.DeleteResponseProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.DeleteSnapshotRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.DeleteSnapshotResponseProto;
+import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.DisallowSnapshotRequestProto;
+import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.DisallowSnapshotResponseProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.FinalizeUpgradeRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.FinalizeUpgradeResponseProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.FsyncRequestProto;
@@ -132,6 +136,7 @@ import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.Update
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.UpdateBlockForPipelineResponseProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.UpdatePipelineRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.UpdatePipelineResponseProto;
+
 import org.apache.hadoop.hdfs.protocol.proto.HdfsProtos.BlockTokenIdentifierProto;
 import org.apache.hadoop.hdfs.protocol.proto.HdfsProtos.DatanodeIDProto;
 import org.apache.hadoop.hdfs.protocol.proto.HdfsProtos.DatanodeInfoProto;
@@ -159,7 +164,10 @@ public class ClientNamenodeProtocolServerSideTranslatorPB implements
       DeleteSnapshotResponseProto.newBuilder().build();
   static final CreateSnapshotResponseProto VOID_CREATE_SNAPSHOT_RESPONSE =
       CreateSnapshotResponseProto.newBuilder().build();
-  
+  static final AllowSnapshotResponseProto VOID_ALLOW_SNAPSHOT_RESPONSE = 
+      AllowSnapshotResponseProto.newBuilder().build();
+  static final DisallowSnapshotResponseProto VOID_DISALLOW_SNAPSHOT_RESPONSE =
+      DisallowSnapshotResponseProto.newBuilder().build();
 
   /**
    * Constructor
@@ -904,4 +912,26 @@ public class ClientNamenodeProtocolServerSideTranslatorPB implements
       throw new ServiceException(e);
     }
   }
+
+  @Override
+  public AllowSnapshotResponseProto allowSnapshot(RpcController controller,
+      AllowSnapshotRequestProto req) throws ServiceException {
+    try {
+      server.allowSnapshot(req.getSnapshotRoot());
+      return VOID_ALLOW_SNAPSHOT_RESPONSE;
+    } catch (IOException e) {
+      throw new ServiceException(e);
+    }
+  }
+
+  @Override
+  public DisallowSnapshotResponseProto disallowSnapshot(RpcController controller,
+      DisallowSnapshotRequestProto req) throws ServiceException {
+    try {
+      server.disallowSnapshot(req.getSnapshotRoot());
+      return VOID_DISALLOW_SNAPSHOT_RESPONSE;
+    } catch (IOException e) {
+      throw new ServiceException(e);
+    }
+  }
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/ClientNamenodeProtocolTranslatorPB.java

@@ -50,6 +50,7 @@ import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
 import org.apache.hadoop.hdfs.protocol.NSQuotaExceededException;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.AbandonBlockRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.AddBlockRequestProto;
+import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.AllowSnapshotRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.AppendRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.AppendResponseProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.CancelDelegationTokenRequestProto;
@@ -60,6 +61,7 @@ import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.Create
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.CreateSymlinkRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.DeleteRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.DeleteSnapshotRequestProto;
+import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.DisallowSnapshotRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.FinalizeUpgradeRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.FsyncRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.GetAdditionalDatanodeRequestProto;
@@ -879,4 +881,26 @@ public class ClientNamenodeProtocolTranslatorPB implements
       throw ProtobufHelper.getRemoteException(e);
     }
   }
+
+  @Override
+  public void allowSnapshot(String snapshotRoot) throws IOException {
+    AllowSnapshotRequestProto req = AllowSnapshotRequestProto.newBuilder()
+        .setSnapshotRoot(snapshotRoot).build();
+    try {
+      rpcProxy.allowSnapshot(null, req);
+    } catch (ServiceException e) {
+      throw ProtobufHelper.getRemoteException(e);
+    }
+  }
+
+  @Override
+  public void disallowSnapshot(String snapshotRoot) throws IOException {
+    DisallowSnapshotRequestProto req = DisallowSnapshotRequestProto
+        .newBuilder().setSnapshotRoot(snapshotRoot).build();
+    try {
+      rpcProxy.disallowSnapshot(null, req);
+    } catch (ServiceException e) {
+      throw ProtobufHelper.getRemoteException(e);
+    }
+  }
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java

@@ -140,6 +140,7 @@ import org.apache.hadoop.hdfs.protocol.LocatedBlock;
 import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
 import org.apache.hadoop.hdfs.protocol.QuotaExceededException;
 import org.apache.hadoop.hdfs.protocol.RecoveryInProgressException;
+import org.apache.hadoop.hdfs.protocol.SnapshotInfo;
 import org.apache.hadoop.hdfs.protocol.datatransfer.ReplaceDatanodeOnFailure;
 import org.apache.hadoop.hdfs.security.token.block.BlockTokenSecretManager;
 import org.apache.hadoop.hdfs.security.token.block.BlockTokenSecretManager.AccessMode;
@@ -5556,4 +5557,18 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
     return this.blockManager.getDatanodeManager()
         .isAvoidingStaleDataNodesForWrite();
   }
+  
+  // Allow snapshot on a directroy.
+  @VisibleForTesting
+  public void allowSnapshot(String snapshotRoot)
+      throws SafeModeException, IOException {
+    // TODO: implement
+  }
+  
+  // Disallow snapshot on a directory.
+  @VisibleForTesting
+  public void disallowSnapshot(String snapshotRoot)
+      throws SafeModeException, IOException {
+    // TODO: implement
+  }
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNodeRpcServer.java

@@ -1093,4 +1093,16 @@ class NameNodeRpcServer implements NamenodeProtocols {
     si[0] = new SnapshotInfo(null, null, null, null, null, null);
     return si;
   }
+
+  @Override
+  // Client Protocol
+  public void allowSnapshot(String snapshotRoot) throws IOException {
+    namesystem.allowSnapshot(snapshotRoot);
+  }
+
+  @Override
+  // Client Protocol
+  public void disallowSnapshot(String snapshot) throws IOException {
+    namesystem.disallowSnapshot(snapshot);
+  }
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/DFSAdmin.java

@@ -406,6 +406,30 @@ public class DFSAdmin extends FsShell {
     System.out.println("Safe mode is " + (inSafeMode ? "ON" : "OFF"));
   }
 
+  /**
+   * Allow snapshot on a directory.
+   * Usage: java DFSAdmin -allowSnapshot <snapshotRoot>
+   * @param argv List of of command line parameters.
+   * @exception IOException
+   */
+  public void allowSnapshot(String[] argv) throws IOException {   
+    DistributedFileSystem dfs = getDFS();
+    dfs.allowSnapshot(argv[1]);
+    System.out.println("Allowing snaphot on " + argv[1] + " succeeded");
+  }
+  
+  /**
+   * Allow snapshot on a directory.
+   * Usage: java DFSAdmin -disallowSnapshot <snapshotRoot>
+   * @param argv List of of command line parameters.
+   * @exception IOException
+   */
+  public void disallowSnapshot(String[] argv) throws IOException {  
+    DistributedFileSystem dfs = getDFS();
+    dfs.disallowSnapshot(argv[1]);
+    System.out.println("Disallowing snaphot on " + argv[1] + " succeeded");
+  }
+  
   /**
    * Command to ask the namenode to save the namespace.
    * Usage: java DFSAdmin -saveNamespace
@@ -879,7 +903,13 @@ public class DFSAdmin extends FsShell {
                          + " [-report]");
     } else if ("-safemode".equals(cmd)) {
       System.err.println("Usage: java DFSAdmin"
-                         + " [-safemode enter | leave | get | wait]");
+          + " [-safemode enter | leave | get | wait]");
+    } else if ("-allowSnapshot".equalsIgnoreCase(cmd)) {
+      System.err.println("Usage: java DFSAdmin"
+          + " [-allowSnapshot <snapshotRoot>]");
+    } else if ("-disallowsnapshot".equalsIgnoreCase(cmd)) {
+      System.err.println("Usage: java DFSAdmin"
+          + " [-disallowSnapshot <snapshotRoot>]");
     } else if ("-saveNamespace".equals(cmd)) {
       System.err.println("Usage: java DFSAdmin"
                          + " [-saveNamespace]");
@@ -938,7 +968,9 @@ public class DFSAdmin extends FsShell {
       System.err.println("Usage: java DFSAdmin");
       System.err.println("Note: Administrative commands can only be run as the HDFS superuser.");
       System.err.println("           [-report]");
-      System.err.println("           [-safemode enter | leave | get | wait]");
+      System.err.println("           [-safemode enter | leave | get | wait]"); 
+      System.err.println("           [-allowSnapshot <snapshotRoot>]");
+      System.err.println("           [-disallowSnapshot <snapshotRoot>]");
       System.err.println("           [-saveNamespace]");
       System.err.println("           [-rollEdits]");
       System.err.println("           [-restoreFailedStorage true|false|check]");
@@ -988,6 +1020,16 @@ public class DFSAdmin extends FsShell {
         printUsage(cmd);
         return exitCode;
       }
+    } else if ("-allowSnapshot".equalsIgnoreCase(cmd)) {
+      if (argv.length != 3) {
+        printUsage(cmd);
+        return exitCode;
+      }
+    } else if ("-disallowSnapshot".equalsIgnoreCase(cmd)) {
+      if (argv.length != 2) {
+        printUsage(cmd);
+        return exitCode;
+      }
     } else if ("-report".equals(cmd)) {
       if (argv.length != 1) {
         printUsage(cmd);
@@ -1079,6 +1121,10 @@ public class DFSAdmin extends FsShell {
         report();
       } else if ("-safemode".equals(cmd)) {
         setSafeMode(argv, i);
+      } else if ("-allowSnapshot".equalsIgnoreCase(cmd)) {
+        allowSnapshot(argv);
+      } else if ("-disallowSnapshot".equalsIgnoreCase(cmd)) {
+        disallowSnapshot(argv);
       } else if ("-saveNamespace".equals(cmd)) {
         exitCode = saveNamespace();
       } else if ("-rollEdits".equals(cmd)) {

hadoop-hdfs-project/hadoop-hdfs/src/main/proto/ClientNamenodeProtocol.proto

@@ -466,6 +466,20 @@ message ListSnapshotsResponseProto {
   repeated SnapshotInfoProto snapshots = 1;
 }
 
+message AllowSnapshotRequestProto {
+  required string snapshotRoot = 1;
+}
+
+message AllowSnapshotResponseProto {
+}
+
+message DisallowSnapshotRequestProto {
+  required string snapshotRoot = 1;
+}
+
+message DisallowSnapshotResponseProto {
+}
+
 service ClientNamenodeProtocol {
   rpc getBlockLocations(GetBlockLocationsRequestProto)
       returns(GetBlockLocationsResponseProto);
@@ -545,4 +559,8 @@ service ClientNamenodeProtocol {
       returns(DeleteSnapshotResponseProto);
   rpc listSnapshots(ListSnapshotsRequestProto)
       returns(ListSnapshotsResponseProto);
+  rpc allowSnapshot(AllowSnapshotRequestProto)
+      returns(AllowSnapshotResponseProto);
+  rpc disallowSnapshot(DisallowSnapshotRequestProto)
+      returns(DisallowSnapshotResponseProto);   
 }