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Posted to common-commits@hadoop.apache.org by ji...@apache.org on 2015/01/27 21:58:24 UTC

[3/3] hadoop git commit: HDFS-3689. Add support for variable length block. Contributed by Jing Zhao.

HDFS-3689. Add support for variable length block. Contributed by Jing Zhao.


Project: http://git-wip-us.apache.org/repos/asf/hadoop/repo
Commit: http://git-wip-us.apache.org/repos/asf/hadoop/commit/2848db81
Tree: http://git-wip-us.apache.org/repos/asf/hadoop/tree/2848db81
Diff: http://git-wip-us.apache.org/repos/asf/hadoop/diff/2848db81

Branch: refs/heads/trunk
Commit: 2848db814a98b83e7546f65a2751e56fb5b2dbe0
Parents: 1e2d98a
Author: Jing Zhao <ji...@apache.org>
Authored: Tue Jan 27 12:58:10 2015 -0800
Committer: Jing Zhao <ji...@apache.org>
Committed: Tue Jan 27 12:58:10 2015 -0800

----------------------------------------------------------------------
 .../java/org/apache/hadoop/fs/CreateFlag.java   |  24 +-
 .../org/apache/hadoop/fs/FSOutputSummer.java    |   2 +-
 .../hadoop/hdfs/nfs/nfs3/WriteManager.java      |   5 +-
 hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt     |   2 +
 .../java/org/apache/hadoop/hdfs/DFSClient.java  |  48 +-
 .../org/apache/hadoop/hdfs/DFSOutputStream.java |  69 +--
 .../hadoop/hdfs/DistributedFileSystem.java      |  10 +-
 .../hdfs/client/HdfsDataOutputStream.java       |   8 +-
 .../org/apache/hadoop/hdfs/inotify/Event.java   |  12 +
 .../hadoop/hdfs/protocol/ClientProtocol.java    |   9 +-
 ...tNamenodeProtocolServerSideTranslatorPB.java |  14 +-
 .../ClientNamenodeProtocolTranslatorPB.java     |  17 +-
 .../apache/hadoop/hdfs/protocolPB/PBHelper.java |  25 +-
 .../datanode/web/webhdfs/WebHdfsHandler.java    |   3 +-
 .../hdfs/server/namenode/FSDirConcatOp.java     | 259 +++++------
 .../hdfs/server/namenode/FSDirectory.java       |   4 +-
 .../hadoop/hdfs/server/namenode/FSEditLog.java  |  20 +-
 .../hdfs/server/namenode/FSEditLogLoader.java   |  64 ++-
 .../hdfs/server/namenode/FSEditLogOp.java       | 101 ++++-
 .../hdfs/server/namenode/FSEditLogOpCodes.java  |   1 +
 .../hdfs/server/namenode/FSNamesystem.java      |  56 ++-
 .../hadoop/hdfs/server/namenode/INodeFile.java  |   2 +-
 .../namenode/InotifyFSEditLogOpTranslator.java  |   4 +
 .../server/namenode/NameNodeLayoutVersion.java  |   3 +-
 .../hdfs/server/namenode/NameNodeRpcServer.java |   9 +-
 .../src/main/proto/ClientNamenodeProtocol.proto |   2 +
 .../hadoop-hdfs/src/main/proto/inotify.proto    |   1 +
 .../org/apache/hadoop/hdfs/AppendTestUtil.java  |  16 +
 .../org/apache/hadoop/hdfs/DFSTestUtil.java     |   3 +
 .../hdfs/TestDFSInotifyEventInputStream.java    |   9 +-
 .../org/apache/hadoop/hdfs/TestFileAppend.java  | 162 +++++++
 .../org/apache/hadoop/hdfs/TestFileAppend2.java | 193 +++++++-
 .../org/apache/hadoop/hdfs/TestFileAppend3.java | 212 +++++++--
 .../hadoop/hdfs/TestFileAppendRestart.java      |  10 +-
 .../java/org/apache/hadoop/hdfs/TestHFlush.java | 128 +++++-
 .../apache/hadoop/hdfs/TestLeaseRecovery.java   |   6 +-
 .../fsdataset/impl/TestLazyPersistFiles.java    |   5 +-
 .../hdfs/server/namenode/TestHDFSConcat.java    |  78 +++-
 .../server/namenode/TestNamenodeRetryCache.java |  16 +-
 .../namenode/ha/TestRetryCacheWithHA.java       |  10 +-
 .../hadoop-hdfs/src/test/resources/editsStored  | Bin 5586 -> 5803 bytes
 .../src/test/resources/editsStored.xml          | 437 ++++++++++---------
 42 files changed, 1509 insertions(+), 550 deletions(-)
----------------------------------------------------------------------


http://git-wip-us.apache.org/repos/asf/hadoop/blob/2848db81/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/CreateFlag.java
----------------------------------------------------------------------
diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/CreateFlag.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/CreateFlag.java
index c5d23b4..e008ecc 100644
--- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/CreateFlag.java
+++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/CreateFlag.java
@@ -47,6 +47,10 @@ import org.apache.hadoop.classification.InterfaceStability;
  * <li> SYNC_BLOCK - to force closed blocks to the disk device.
  * In addition {@link Syncable#hsync()} should be called after each write,
  * if true synchronous behavior is required.</li>
+ * <li> LAZY_PERSIST - Create the block on transient storage (RAM) if
+ * available.</li>
+ * <li> APPEND_NEWBLOCK - Append data to a new block instead of end of the last
+ * partial block.</li>
  * </ol>
  * 
  * Following combination is not valid and will result in 
@@ -93,7 +97,13 @@ public enum CreateFlag {
    * This flag must only be used for intermediate data whose loss can be
    * tolerated by the application.
    */
-  LAZY_PERSIST((short) 0x10);
+  LAZY_PERSIST((short) 0x10),
+
+  /**
+   * Append data to a new block instead of the end of the last partial block.
+   * This is only useful for APPEND.
+   */
+  NEW_BLOCK((short) 0x20);
 
   private final short mode;
 
@@ -149,4 +159,16 @@ public enum CreateFlag {
           + ". Create option is not specified in " + flag);
     }
   }
+
+  /**
+   * Validate the CreateFlag for the append operation. The flag must contain
+   * APPEND, and cannot contain OVERWRITE.
+   */
+  public static void validateForAppend(EnumSet<CreateFlag> flag) {
+    validate(flag);
+    if (!flag.contains(APPEND)) {
+      throw new HadoopIllegalArgumentException(flag
+          + " does not contain APPEND");
+    }
+  }
 }
\ No newline at end of file

http://git-wip-us.apache.org/repos/asf/hadoop/blob/2848db81/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FSOutputSummer.java
----------------------------------------------------------------------
diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FSOutputSummer.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FSOutputSummer.java
index 934421a..13a5e26 100644
--- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FSOutputSummer.java
+++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FSOutputSummer.java
@@ -165,7 +165,7 @@ abstract public class FSOutputSummer extends OutputStream {
         count = partialLen;
         System.arraycopy(buf, bufLen - count, buf, 0, count);
       } else {
-      count = 0;
+        count = 0;
       }
     }
 

http://git-wip-us.apache.org/repos/asf/hadoop/blob/2848db81/hadoop-hdfs-project/hadoop-hdfs-nfs/src/main/java/org/apache/hadoop/hdfs/nfs/nfs3/WriteManager.java
----------------------------------------------------------------------
diff --git a/hadoop-hdfs-project/hadoop-hdfs-nfs/src/main/java/org/apache/hadoop/hdfs/nfs/nfs3/WriteManager.java b/hadoop-hdfs-project/hadoop-hdfs-nfs/src/main/java/org/apache/hadoop/hdfs/nfs/nfs3/WriteManager.java
index df02e04..52c75ed 100644
--- a/hadoop-hdfs-project/hadoop-hdfs-nfs/src/main/java/org/apache/hadoop/hdfs/nfs/nfs3/WriteManager.java
+++ b/hadoop-hdfs-project/hadoop-hdfs-nfs/src/main/java/org/apache/hadoop/hdfs/nfs/nfs3/WriteManager.java
@@ -18,10 +18,12 @@
 package org.apache.hadoop.hdfs.nfs.nfs3;
 
 import java.io.IOException;
+import java.util.EnumSet;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.fs.CommonConfigurationKeysPublic;
+import org.apache.hadoop.fs.CreateFlag;
 import org.apache.hadoop.hdfs.DFSClient;
 import org.apache.hadoop.hdfs.client.HdfsDataOutputStream;
 import org.apache.hadoop.hdfs.nfs.conf.NfsConfigKeys;
@@ -147,7 +149,8 @@ public class WriteManager {
             CommonConfigurationKeysPublic.IO_FILE_BUFFER_SIZE_KEY,
             CommonConfigurationKeysPublic.IO_FILE_BUFFER_SIZE_DEFAULT);
         
-        fos = dfsClient.append(fileIdPath, bufferSize, null, null);
+        fos = dfsClient.append(fileIdPath, bufferSize,
+            EnumSet.of(CreateFlag.APPEND), null, null);
 
         latestAttr = Nfs3Utils.getFileAttr(dfsClient, fileIdPath, iug);
       } catch (RemoteException e) {

http://git-wip-us.apache.org/repos/asf/hadoop/blob/2848db81/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
----------------------------------------------------------------------
diff --git a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
index 1e1af97..b867a70 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
+++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
@@ -18,6 +18,8 @@ Trunk (Unreleased)
 
     HDFS-3125. Add JournalService to enable Journal Daemon. (suresh)
 
+    HDFS-3689. Add support for variable length block. (jing9)
+
   IMPROVEMENTS
 
     HDFS-4665. Move TestNetworkTopologyWithNodeGroup to common.

http://git-wip-us.apache.org/repos/asf/hadoop/blob/2848db81/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSClient.java
----------------------------------------------------------------------
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSClient.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSClient.java
index 21f75a5..8512156 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSClient.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSClient.java
@@ -1656,9 +1656,8 @@ public class DFSClient implements java.io.Closeable, RemotePeerFactory,
    * @param checksumOpt checksum options
    * 
    * @return output stream
-   * 
-   * @see ClientProtocol#create(String, FsPermission, String, EnumSetWritable,
-   * boolean, short, long) for detailed description of exceptions thrown
+   *
+   * @see ClientProtocol#create for detailed description of exceptions thrown
    */
   public DFSOutputStream create(String src, 
                              FsPermission permission,
@@ -1732,7 +1731,7 @@ public class DFSClient implements java.io.Closeable, RemotePeerFactory,
         }
         return null;
       }
-      return callAppend(src, buffersize, progress);
+      return callAppend(src, buffersize, flag, progress);
     }
     return null;
   }
@@ -1810,11 +1809,16 @@ public class DFSClient implements java.io.Closeable, RemotePeerFactory,
   }
 
   /** Method to get stream returned by append call */
-  private DFSOutputStream callAppend(String src,
-      int buffersize, Progressable progress) throws IOException {
-    LastBlockWithStatus lastBlockWithStatus = null;
-    try {
-      lastBlockWithStatus = namenode.append(src, clientName);
+  private DFSOutputStream callAppend(String src, int buffersize,
+      EnumSet<CreateFlag> flag, Progressable progress) throws IOException {
+    CreateFlag.validateForAppend(flag);
+    try {
+      LastBlockWithStatus blkWithStatus = namenode.append(src, clientName,
+          new EnumSetWritable<>(flag, CreateFlag.class));
+      return DFSOutputStream.newStreamForAppend(this, src,
+          flag.contains(CreateFlag.NEW_BLOCK),
+          buffersize, progress, blkWithStatus.getLastBlock(),
+          blkWithStatus.getFileStatus(), dfsClientConf.createChecksum());
     } catch(RemoteException re) {
       throw re.unwrapRemoteException(AccessControlException.class,
                                      FileNotFoundException.class,
@@ -1824,10 +1828,6 @@ public class DFSClient implements java.io.Closeable, RemotePeerFactory,
                                      UnresolvedPathException.class,
                                      SnapshotAccessControlException.class);
     }
-    HdfsFileStatus newStat = lastBlockWithStatus.getFileStatus();
-    return DFSOutputStream.newStreamForAppend(this, src, buffersize, progress,
-        lastBlockWithStatus.getLastBlock(), newStat,
-        dfsClientConf.createChecksum());
   }
   
   /**
@@ -1835,23 +1835,25 @@ public class DFSClient implements java.io.Closeable, RemotePeerFactory,
    * 
    * @param src file name
    * @param buffersize buffer size
+   * @param flag indicates whether to append data to a new block instead of
+   *             the last block
    * @param progress for reporting write-progress; null is acceptable.
    * @param statistics file system statistics; null is acceptable.
    * @return an output stream for writing into the file
    * 
-   * @see ClientProtocol#append(String, String) 
+   * @see ClientProtocol#append(String, String, EnumSetWritable)
    */
   public HdfsDataOutputStream append(final String src, final int buffersize,
-      final Progressable progress, final FileSystem.Statistics statistics
-      ) throws IOException {
-    final DFSOutputStream out = append(src, buffersize, progress);
+      EnumSet<CreateFlag> flag, final Progressable progress,
+      final FileSystem.Statistics statistics) throws IOException {
+    final DFSOutputStream out = append(src, buffersize, flag, progress);
     return createWrappedOutputStream(out, statistics, out.getInitialLen());
   }
 
-  private DFSOutputStream append(String src, int buffersize, Progressable progress) 
-      throws IOException {
+  private DFSOutputStream append(String src, int buffersize,
+      EnumSet<CreateFlag> flag, Progressable progress) throws IOException {
     checkOpen();
-    final DFSOutputStream result = callAppend(src, buffersize, progress);
+    final DFSOutputStream result = callAppend(src, buffersize, flag, progress);
     beginFileLease(result.getFileId(), result);
     return result;
   }
@@ -1938,7 +1940,7 @@ public class DFSClient implements java.io.Closeable, RemotePeerFactory,
 
   /**
    * Move blocks from src to trg and delete src
-   * See {@link ClientProtocol#concat(String, String [])}. 
+   * See {@link ClientProtocol#concat}.
    */
   public void concat(String trg, String [] srcs) throws IOException {
     checkOpen();
@@ -1980,7 +1982,7 @@ public class DFSClient implements java.io.Closeable, RemotePeerFactory,
 
   /**
    * Truncate a file to an indicated size
-   * See {@link ClientProtocol#truncate(String, long)}. 
+   * See {@link ClientProtocol#truncate}.
    */
   public boolean truncate(String src, long newLength) throws IOException {
     checkOpen();
@@ -3005,7 +3007,7 @@ public class DFSClient implements java.io.Closeable, RemotePeerFactory,
   
   /**
    * Get {@link ContentSummary} rooted at the specified directory.
-   * @param path The string representation of the path
+   * @param src The string representation of the path
    * 
    * @see ClientProtocol#getContentSummary(String)
    */

http://git-wip-us.apache.org/repos/asf/hadoop/blob/2848db81/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSOutputStream.java
----------------------------------------------------------------------
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSOutputStream.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSOutputStream.java
index 67d3143..8cebda1 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSOutputStream.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSOutputStream.java
@@ -426,15 +426,16 @@ public class DFSOutputStream extends FSOutputSummer
     /**
      * construction with tracing info
      */
-    private DataStreamer(HdfsFileStatus stat, Span span) {
+    private DataStreamer(HdfsFileStatus stat, ExtendedBlock block, Span span) {
       isAppend = false;
       isLazyPersistFile = isLazyPersist(stat);
+      this.block = block;
       stage = BlockConstructionStage.PIPELINE_SETUP_CREATE;
       traceSpan = span;
     }
     
     /**
-     * Construct a data streamer for append
+     * Construct a data streamer for appending to the last partial block
      * @param lastBlock last block of the file to be appended
      * @param stat status of the file to be appended
      * @param bytesPerChecksum number of bytes per checksum
@@ -1716,7 +1717,7 @@ public class DFSOutputStream extends FSOutputSummer
     if (Trace.isTracing()) {
       traceSpan = Trace.startSpan(this.getClass().getSimpleName()).detach();
     }
-    streamer = new DataStreamer(stat, traceSpan);
+    streamer = new DataStreamer(stat, null, traceSpan);
     if (favoredNodes != null && favoredNodes.length != 0) {
       streamer.setFavoredNodes(favoredNodes);
     }
@@ -1773,7 +1774,7 @@ public class DFSOutputStream extends FSOutputSummer
   }
 
   /** Construct a new output stream for append. */
-  private DFSOutputStream(DFSClient dfsClient, String src,
+  private DFSOutputStream(DFSClient dfsClient, String src, boolean toNewBlock,
       Progressable progress, LocatedBlock lastBlock, HdfsFileStatus stat,
       DataChecksum checksum) throws IOException {
     this(dfsClient, src, progress, stat, checksum);
@@ -1785,21 +1786,24 @@ public class DFSOutputStream extends FSOutputSummer
     }
 
     // The last partial block of the file has to be filled.
-    if (lastBlock != null) {
+    if (!toNewBlock && lastBlock != null) {
       // indicate that we are appending to an existing block
       bytesCurBlock = lastBlock.getBlockSize();
       streamer = new DataStreamer(lastBlock, stat, bytesPerChecksum, traceSpan);
     } else {
-      computePacketChunkSize(dfsClient.getConf().writePacketSize, bytesPerChecksum);
-      streamer = new DataStreamer(stat, traceSpan);
+      computePacketChunkSize(dfsClient.getConf().writePacketSize,
+          bytesPerChecksum);
+      streamer = new DataStreamer(stat,
+          lastBlock != null ? lastBlock.getBlock() : null, traceSpan);
     }
     this.fileEncryptionInfo = stat.getFileEncryptionInfo();
   }
 
   static DFSOutputStream newStreamForAppend(DFSClient dfsClient, String src,
-      int buffersize, Progressable progress, LocatedBlock lastBlock,
-      HdfsFileStatus stat, DataChecksum checksum) throws IOException {
-    final DFSOutputStream out = new DFSOutputStream(dfsClient, src,
+      boolean toNewBlock, int bufferSize, Progressable progress,
+      LocatedBlock lastBlock, HdfsFileStatus stat, DataChecksum checksum)
+      throws IOException {
+    final DFSOutputStream out = new DFSOutputStream(dfsClient, src, toNewBlock,
         progress, lastBlock, stat, checksum);
     out.start();
     return out;
@@ -1995,35 +1999,37 @@ public class DFSOutputStream extends FSOutputSummer
       long toWaitFor;
       long lastBlockLength = -1L;
       boolean updateLength = syncFlags.contains(SyncFlag.UPDATE_LENGTH);
+      boolean endBlock = syncFlags.contains(SyncFlag.END_BLOCK);
       synchronized (this) {
-        // flush checksum buffer, but keep checksum buffer intact
-        int numKept = flushBuffer(true, true);
+        // flush checksum buffer, but keep checksum buffer intact if we do not
+        // need to end the current block
+        int numKept = flushBuffer(!endBlock, true);
         // bytesCurBlock potentially incremented if there was buffered data
 
         if (DFSClient.LOG.isDebugEnabled()) {
-          DFSClient.LOG.debug(
-            "DFSClient flush() :" +
-            " bytesCurBlock " + bytesCurBlock +
-            " lastFlushOffset " + lastFlushOffset);
+          DFSClient.LOG.debug("DFSClient flush():"
+              + " bytesCurBlock=" + bytesCurBlock
+              + " lastFlushOffset=" + lastFlushOffset
+              + " createNewBlock=" + endBlock);
         }
         // Flush only if we haven't already flushed till this offset.
         if (lastFlushOffset != bytesCurBlock) {
           assert bytesCurBlock > lastFlushOffset;
           // record the valid offset of this flush
           lastFlushOffset = bytesCurBlock;
-          if (isSync && currentPacket == null) {
+          if (isSync && currentPacket == null && !endBlock) {
             // Nothing to send right now,
             // but sync was requested.
-            // Send an empty packet
+            // Send an empty packet if we do not end the block right now
             currentPacket = createPacket(packetSize, chunksPerPacket,
                 bytesCurBlock, currentSeqno++);
           }
         } else {
-          if (isSync && bytesCurBlock > 0) {
+          if (isSync && bytesCurBlock > 0 && !endBlock) {
             // Nothing to send right now,
             // and the block was partially written,
             // and sync was requested.
-            // So send an empty sync packet.
+            // So send an empty sync packet if we do not end the block right now
             currentPacket = createPacket(packetSize, chunksPerPacket,
                 bytesCurBlock, currentSeqno++);
           } else if (currentPacket != null) {
@@ -2036,10 +2042,21 @@ public class DFSOutputStream extends FSOutputSummer
           currentPacket.syncBlock = isSync;
           waitAndQueueCurrentPacket();          
         }
-        // Restore state of stream. Record the last flush offset 
-        // of the last full chunk that was flushed.
-        //
-        bytesCurBlock -= numKept;
+        if (endBlock && bytesCurBlock > 0) {
+          // Need to end the current block, thus send an empty packet to
+          // indicate this is the end of the block and reset bytesCurBlock
+          currentPacket = createPacket(0, 0, bytesCurBlock, currentSeqno++);
+          currentPacket.lastPacketInBlock = true;
+          currentPacket.syncBlock = shouldSyncBlock || isSync;
+          waitAndQueueCurrentPacket();
+          bytesCurBlock = 0;
+          lastFlushOffset = 0;
+        } else {
+          // Restore state of stream. Record the last flush offset
+          // of the last full chunk that was flushed.
+          bytesCurBlock -= numKept;
+        }
+
         toWaitFor = lastQueuedSeqno;
       } // end synchronized
 
@@ -2058,8 +2075,8 @@ public class DFSOutputStream extends FSOutputSummer
       // namenode.
       if (persistBlocks.getAndSet(false) || updateLength) {
         try {
-          dfsClient.namenode.fsync(src, fileId,
-              dfsClient.clientName, lastBlockLength);
+          dfsClient.namenode.fsync(src, fileId, dfsClient.clientName,
+              lastBlockLength);
         } catch (IOException ioe) {
           DFSClient.LOG.warn("Unable to persist blocks in hflush for " + src, ioe);
           // If we got an error here, it might be because some other thread called

http://git-wip-us.apache.org/repos/asf/hadoop/blob/2848db81/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DistributedFileSystem.java
----------------------------------------------------------------------
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DistributedFileSystem.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DistributedFileSystem.java
index 654e2f9..710ab18 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DistributedFileSystem.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DistributedFileSystem.java
@@ -314,13 +314,19 @@ public class DistributedFileSystem extends FileSystem {
   @Override
   public FSDataOutputStream append(Path f, final int bufferSize,
       final Progressable progress) throws IOException {
+    return append(f, EnumSet.of(CreateFlag.APPEND), bufferSize, progress);
+  }
+
+  public FSDataOutputStream append(Path f, final EnumSet<CreateFlag> flag,
+      final int bufferSize, final Progressable progress) throws IOException {
     statistics.incrementWriteOps(1);
     Path absF = fixRelativePart(f);
     return new FileSystemLinkResolver<FSDataOutputStream>() {
       @Override
       public FSDataOutputStream doCall(final Path p)
-          throws IOException, UnresolvedLinkException {
-        return dfs.append(getPathName(p), bufferSize, progress, statistics);
+          throws IOException {
+        return dfs.append(getPathName(p), bufferSize, flag, progress,
+            statistics);
       }
       @Override
       public FSDataOutputStream next(final FileSystem fs, final Path p)

http://git-wip-us.apache.org/repos/asf/hadoop/blob/2848db81/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/client/HdfsDataOutputStream.java
----------------------------------------------------------------------
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/client/HdfsDataOutputStream.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/client/HdfsDataOutputStream.java
index 2149678..745ca7e 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/client/HdfsDataOutputStream.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/client/HdfsDataOutputStream.java
@@ -101,6 +101,12 @@ public class HdfsDataOutputStream extends FSDataOutputStream {
      * When doing sync to DataNodes, also update the metadata (block length) in
      * the NameNode.
      */
-    UPDATE_LENGTH;
+    UPDATE_LENGTH,
+
+    /**
+     * Sync the data to DataNode, close the current block, and allocate a new
+     * block
+     */
+    END_BLOCK;
   }
 }

http://git-wip-us.apache.org/repos/asf/hadoop/blob/2848db81/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/inotify/Event.java
----------------------------------------------------------------------
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/inotify/Event.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/inotify/Event.java
index 5ceff1b..a6de289 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/inotify/Event.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/inotify/Event.java
@@ -463,15 +463,22 @@ public abstract class Event {
    */
   public static class AppendEvent extends Event {
     private String path;
+    private boolean newBlock;
 
     public static class Builder {
       private String path;
+      private boolean newBlock;
 
       public Builder path(String path) {
         this.path = path;
         return this;
       }
 
+      public Builder newBlock(boolean newBlock) {
+        this.newBlock = newBlock;
+        return this;
+      }
+
       public AppendEvent build() {
         return new AppendEvent(this);
       }
@@ -480,11 +487,16 @@ public abstract class Event {
     private AppendEvent(Builder b) {
       super(EventType.APPEND);
       this.path = b.path;
+      this.newBlock = b.newBlock;
     }
 
     public String getPath() {
       return path;
     }
+
+    public boolean toNewBlock() {
+      return newBlock;
+    }
   }
 
   /**

http://git-wip-us.apache.org/repos/asf/hadoop/blob/2848db81/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/ClientProtocol.java
----------------------------------------------------------------------
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/ClientProtocol.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/ClientProtocol.java
index cfd1c67..cba1982 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/ClientProtocol.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/ClientProtocol.java
@@ -203,6 +203,7 @@ public interface ClientProtocol {
    * Append to the end of the file. 
    * @param src path of the file being created.
    * @param clientName name of the current client.
+   * @param flag indicates whether the data is appended to a new block.
    * @return wrapper with information about the last partial block and file
    *    status if any
    * @throws AccessControlException if permission to append file is 
@@ -225,10 +226,10 @@ public interface ClientProtocol {
    * @throws UnsupportedOperationException if append is not supported
    */
   @AtMostOnce
-  public LastBlockWithStatus append(String src, String clientName)
-      throws AccessControlException, DSQuotaExceededException,
-      FileNotFoundException, SafeModeException, UnresolvedLinkException,
-      SnapshotAccessControlException, IOException;
+  public LastBlockWithStatus append(String src, String clientName,
+      EnumSetWritable<CreateFlag> flag) throws AccessControlException,
+      DSQuotaExceededException, FileNotFoundException, SafeModeException,
+      UnresolvedLinkException, SnapshotAccessControlException, IOException;
 
   /**
    * Set replication for an existing file.

http://git-wip-us.apache.org/repos/asf/hadoop/blob/2848db81/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/ClientNamenodeProtocolServerSideTranslatorPB.java
----------------------------------------------------------------------
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/ClientNamenodeProtocolServerSideTranslatorPB.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/ClientNamenodeProtocolServerSideTranslatorPB.java
index 8bcc1eb..dbb8b85 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/ClientNamenodeProtocolServerSideTranslatorPB.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/ClientNamenodeProtocolServerSideTranslatorPB.java
@@ -18,12 +18,14 @@
 package org.apache.hadoop.hdfs.protocolPB;
 
 import java.io.IOException;
+import java.util.EnumSet;
 import java.util.List;
 
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.fs.BatchedRemoteIterator.BatchedEntries;
 import org.apache.hadoop.fs.ContentSummary;
+import org.apache.hadoop.fs.CreateFlag;
 import org.apache.hadoop.fs.FsServerDefaults;
 import org.apache.hadoop.fs.Options.Rename;
 import org.apache.hadoop.hdfs.protocol.BlockStoragePolicy;
@@ -65,6 +67,8 @@ import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.AllowS
 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.CheckAccessRequestProto;
+import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.CheckAccessResponseProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.CompleteRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.CompleteResponseProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.ConcatRequestProto;
@@ -187,8 +191,6 @@ 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.ClientNamenodeProtocolProtos.CheckAccessRequestProto;
-import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.CheckAccessResponseProto;
 import org.apache.hadoop.hdfs.protocol.proto.EncryptionZonesProtos.CreateEncryptionZoneResponseProto;
 import org.apache.hadoop.hdfs.protocol.proto.EncryptionZonesProtos.CreateEncryptionZoneRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.EncryptionZonesProtos.GetEZForPathResponseProto;
@@ -209,6 +211,7 @@ import org.apache.hadoop.hdfs.protocol.proto.XAttrProtos.SetXAttrResponseProto;
 import org.apache.hadoop.hdfs.security.token.block.DataEncryptionKey;
 import org.apache.hadoop.hdfs.security.token.delegation.DelegationTokenIdentifier;
 import org.apache.hadoop.hdfs.server.namenode.INodeId;
+import org.apache.hadoop.io.EnumSetWritable;
 import org.apache.hadoop.io.Text;
 import org.apache.hadoop.security.proto.SecurityProtos.CancelDelegationTokenRequestProto;
 import org.apache.hadoop.security.proto.SecurityProtos.CancelDelegationTokenResponseProto;
@@ -412,8 +415,11 @@ public class ClientNamenodeProtocolServerSideTranslatorPB implements
   public AppendResponseProto append(RpcController controller,
       AppendRequestProto req) throws ServiceException {
     try {
+      EnumSetWritable<CreateFlag> flags = req.hasFlag() ?
+          PBHelper.convertCreateFlag(req.getFlag()) :
+          new EnumSetWritable<>(EnumSet.of(CreateFlag.APPEND));
       LastBlockWithStatus result = server.append(req.getSrc(),
-          req.getClientName());
+          req.getClientName(), flags);
       AppendResponseProto.Builder builder = AppendResponseProto.newBuilder();
       if (result.getLastBlock() != null) {
         builder.setBlock(PBHelper.convert(result.getLastBlock()));
@@ -522,7 +528,7 @@ public class ClientNamenodeProtocolServerSideTranslatorPB implements
       throw new ServiceException(e);
     }
   }
-  
+
   @Override
   public CompleteResponseProto complete(RpcController controller,
       CompleteRequestProto req) throws ServiceException {

http://git-wip-us.apache.org/repos/asf/hadoop/blob/2848db81/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/ClientNamenodeProtocolTranslatorPB.java
----------------------------------------------------------------------
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/ClientNamenodeProtocolTranslatorPB.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/ClientNamenodeProtocolTranslatorPB.java
index f3826af..1d6c0ee 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/ClientNamenodeProtocolTranslatorPB.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/ClientNamenodeProtocolTranslatorPB.java
@@ -28,7 +28,6 @@ import com.google.common.collect.Lists;
 
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;
-import org.apache.hadoop.crypto.CipherSuite;
 import org.apache.hadoop.crypto.CryptoProtocolVersion;
 import org.apache.hadoop.fs.BatchedRemoteIterator.BatchedEntries;
 import org.apache.hadoop.fs.CacheFlag;
@@ -85,6 +84,7 @@ import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.AllowS
 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.CachePoolEntryProto;
+import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.CheckAccessRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.CompleteRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.ConcatRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.CreateRequestProto;
@@ -158,13 +158,11 @@ import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.SetTim
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.TruncateRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.UpdateBlockForPipelineRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.UpdatePipelineRequestProto;
-import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.CheckAccessRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.SetStoragePolicyRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.EncryptionZonesProtos;
 import org.apache.hadoop.hdfs.protocol.proto.EncryptionZonesProtos.CreateEncryptionZoneRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.EncryptionZonesProtos.GetEZForPathRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.EncryptionZonesProtos.ListEncryptionZonesRequestProto;
-import org.apache.hadoop.hdfs.protocol.proto.HdfsProtos;
 import org.apache.hadoop.hdfs.protocol.proto.XAttrProtos.GetXAttrsRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.XAttrProtos.ListXAttrsRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.XAttrProtos.RemoveXAttrRequestProto;
@@ -318,13 +316,12 @@ public class ClientNamenodeProtocolTranslatorPB implements
   }
 
   @Override
-  public LastBlockWithStatus append(String src, String clientName)
-      throws AccessControlException, DSQuotaExceededException,
-      FileNotFoundException, SafeModeException, UnresolvedLinkException,
-      IOException {
-    AppendRequestProto req = AppendRequestProto.newBuilder()
-        .setSrc(src)
-        .setClientName(clientName)
+  public LastBlockWithStatus append(String src, String clientName,
+      EnumSetWritable<CreateFlag> flag) throws AccessControlException,
+      DSQuotaExceededException, FileNotFoundException, SafeModeException,
+      UnresolvedLinkException, IOException {
+    AppendRequestProto req = AppendRequestProto.newBuilder().setSrc(src)
+        .setClientName(clientName).setFlag(PBHelper.convertCreateFlag(flag))
         .build();
     try {
       AppendResponseProto res = rpcProxy.append(null, req);

http://git-wip-us.apache.org/repos/asf/hadoop/blob/2848db81/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/PBHelper.java
----------------------------------------------------------------------
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/PBHelper.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/PBHelper.java
index 7187838..e4746cc 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/PBHelper.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/PBHelper.java
@@ -1373,6 +1373,9 @@ public class PBHelper {
     if (flag.contains(CreateFlag.LAZY_PERSIST)) {
       value |= CreateFlagProto.LAZY_PERSIST.getNumber();
     }
+    if (flag.contains(CreateFlag.NEW_BLOCK)) {
+      value |= CreateFlagProto.NEW_BLOCK.getNumber();
+    }
     return value;
   }
   
@@ -1393,7 +1396,11 @@ public class PBHelper {
         == CreateFlagProto.LAZY_PERSIST_VALUE) {
       result.add(CreateFlag.LAZY_PERSIST);
     }
-    return new EnumSetWritable<CreateFlag>(result);
+    if ((flag & CreateFlagProto.NEW_BLOCK_VALUE)
+        == CreateFlagProto.NEW_BLOCK_VALUE) {
+      result.add(CreateFlag.NEW_BLOCK);
+    }
+    return new EnumSetWritable<CreateFlag>(result, CreateFlag.class);
   }
 
   public static int convertCacheFlags(EnumSet<CacheFlag> flags) {
@@ -2605,11 +2612,11 @@ public class PBHelper {
                   .build());
             break;
           case EVENT_APPEND:
-            InotifyProtos.AppendEventProto reopen =
+            InotifyProtos.AppendEventProto append =
                 InotifyProtos.AppendEventProto.parseFrom(p.getContents());
-            events.add(new Event.AppendEvent.Builder()
-                  .path(reopen.getPath())
-                  .build());
+            events.add(new Event.AppendEvent.Builder().path(append.getPath())
+                .newBlock(append.hasNewBlock() && append.getNewBlock())
+                .build());
             break;
           case EVENT_UNLINK:
             InotifyProtos.UnlinkEventProto unlink =
@@ -2710,10 +2717,10 @@ public class PBHelper {
             Event.AppendEvent re2 = (Event.AppendEvent) e;
             events.add(InotifyProtos.EventProto.newBuilder()
                 .setType(InotifyProtos.EventType.EVENT_APPEND)
-                .setContents(
-                    InotifyProtos.AppendEventProto.newBuilder()
-                        .setPath(re2.getPath()).build().toByteString()
-                ).build());
+                .setContents(InotifyProtos.AppendEventProto.newBuilder()
+                    .setPath(re2.getPath())
+                    .setNewBlock(re2.toNewBlock()).build().toByteString())
+                .build());
             break;
           case UNLINK:
             Event.UnlinkEvent ue = (Event.UnlinkEvent) e;

http://git-wip-us.apache.org/repos/asf/hadoop/blob/2848db81/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/webhdfs/WebHdfsHandler.java
----------------------------------------------------------------------
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/webhdfs/WebHdfsHandler.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/webhdfs/WebHdfsHandler.java
index f02780a..be1faec 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/webhdfs/WebHdfsHandler.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/webhdfs/WebHdfsHandler.java
@@ -176,7 +176,8 @@ public class WebHdfsHandler extends SimpleChannelInboundHandler<HttpRequest> {
     final int bufferSize = params.bufferSize();
 
     DFSClient dfsClient = newDfsClient(nnId, conf);
-    OutputStream out = dfsClient.append(path, bufferSize, null, null);
+    OutputStream out = dfsClient.append(path, bufferSize,
+        EnumSet.of(CreateFlag.APPEND), null, null);
     DefaultHttpResponse resp = new DefaultHttpResponse(HTTP_1_1, OK);
     resp.headers().set(CONTENT_LENGTH, 0);
     ctx.pipeline().replace(this, HdfsWriter.class.getSimpleName(),

http://git-wip-us.apache.org/repos/asf/hadoop/blob/2848db81/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSDirConcatOp.java
----------------------------------------------------------------------
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSDirConcatOp.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSDirConcatOp.java
index 43d3b20..ecfd2e1 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSDirConcatOp.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSDirConcatOp.java
@@ -19,11 +19,10 @@ package org.apache.hadoop.hdfs.server.namenode;
 
 import com.google.common.base.Preconditions;
 import org.apache.hadoop.HadoopIllegalArgumentException;
-import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.fs.permission.FsAction;
 import org.apache.hadoop.hdfs.protocol.HdfsFileStatus;
+import org.apache.hadoop.hdfs.protocol.QuotaExceededException;
 import org.apache.hadoop.hdfs.protocol.SnapshotException;
-import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfo;
 
 import java.io.IOException;
 import java.util.Arrays;
@@ -33,201 +32,171 @@ import java.util.Set;
 import static org.apache.hadoop.util.Time.now;
 
 class FSDirConcatOp {
-  static HdfsFileStatus concat(
-    FSDirectory fsd, String target, String[] srcs,
+
+  static HdfsFileStatus concat(FSDirectory fsd, String target, String[] srcs,
     boolean logRetryCache) throws IOException {
     Preconditions.checkArgument(!target.isEmpty(), "Target file name is empty");
     Preconditions.checkArgument(srcs != null && srcs.length > 0,
       "No sources given");
     assert srcs != null;
-
-    FSDirectory.LOG.debug("concat {} to {}", Arrays.toString(srcs), target);
-    // We require all files be in the same directory
-    String trgParent =
-      target.substring(0, target.lastIndexOf(Path.SEPARATOR_CHAR));
-    for (String s : srcs) {
-      String srcParent = s.substring(0, s.lastIndexOf(Path.SEPARATOR_CHAR));
-      if (!srcParent.equals(trgParent)) {
-        throw new IllegalArgumentException(
-           "Sources and target are not in the same directory");
-      }
+    if (FSDirectory.LOG.isDebugEnabled()) {
+      FSDirectory.LOG.debug("concat {} to {}", Arrays.toString(srcs), target);
     }
 
-    final INodesInPath trgIip = fsd.getINodesInPath4Write(target);
+    final INodesInPath targetIIP = fsd.getINodesInPath4Write(target);
     // write permission for the target
+    FSPermissionChecker pc = null;
     if (fsd.isPermissionEnabled()) {
-      FSPermissionChecker pc = fsd.getPermissionChecker();
-      fsd.checkPathAccess(pc, trgIip, FsAction.WRITE);
-
-      // and srcs
-      for(String aSrc: srcs) {
-        final INodesInPath srcIip = fsd.getINodesInPath4Write(aSrc);
-        fsd.checkPathAccess(pc, srcIip, FsAction.READ); // read the file
-        fsd.checkParentAccess(pc, srcIip, FsAction.WRITE); // for delete
-      }
+      pc = fsd.getPermissionChecker();
+      fsd.checkPathAccess(pc, targetIIP, FsAction.WRITE);
     }
 
-    // to make sure no two files are the same
-    Set<INode> si = new HashSet<INode>();
+    // check the target
+    verifyTargetFile(fsd, target, targetIIP);
+    // check the srcs
+    INodeFile[] srcFiles = verifySrcFiles(fsd, srcs, targetIIP, pc);
 
-    // we put the following prerequisite for the operation
-    // replication and blocks sizes should be the same for ALL the blocks
+    if(NameNode.stateChangeLog.isDebugEnabled()) {
+      NameNode.stateChangeLog.debug("DIR* NameSystem.concat: " +
+          Arrays.toString(srcs) + " to " + target);
+    }
+
+    long timestamp = now();
+    fsd.writeLock();
+    try {
+      unprotectedConcat(fsd, targetIIP, srcFiles, timestamp);
+    } finally {
+      fsd.writeUnlock();
+    }
+    fsd.getEditLog().logConcat(target, srcs, timestamp, logRetryCache);
+    return fsd.getAuditFileInfo(targetIIP);
+  }
 
+  private static void verifyTargetFile(FSDirectory fsd, final String target,
+      final INodesInPath targetIIP) throws IOException {
     // check the target
-    if (fsd.getEZForPath(trgIip) != null) {
+    if (fsd.getEZForPath(targetIIP) != null) {
       throw new HadoopIllegalArgumentException(
           "concat can not be called for files in an encryption zone.");
     }
-    final INodeFile trgInode = INodeFile.valueOf(trgIip.getLastINode(), target);
-    if(trgInode.isUnderConstruction()) {
+    final INodeFile targetINode = INodeFile.valueOf(targetIIP.getLastINode(),
+        target);
+    if(targetINode.isUnderConstruction()) {
       throw new HadoopIllegalArgumentException("concat: target file "
           + target + " is under construction");
     }
-    // per design target shouldn't be empty and all the blocks same size
-    if(trgInode.numBlocks() == 0) {
-      throw new HadoopIllegalArgumentException("concat: target file "
-          + target + " is empty");
-    }
-    if (trgInode.isWithSnapshot()) {
-      throw new HadoopIllegalArgumentException("concat: target file "
-          + target + " is in a snapshot");
-    }
-
-    long blockSize = trgInode.getPreferredBlockSize();
-
-    // check the end block to be full
-    final BlockInfo last = trgInode.getLastBlock();
-    if(blockSize != last.getNumBytes()) {
-      throw new HadoopIllegalArgumentException("The last block in " + target
-          + " is not full; last block size = " + last.getNumBytes()
-          + " but file block size = " + blockSize);
-    }
-
-    si.add(trgInode);
-    final short repl = trgInode.getFileReplication();
+  }
 
+  private static INodeFile[] verifySrcFiles(FSDirectory fsd, String[] srcs,
+      INodesInPath targetIIP, FSPermissionChecker pc) throws IOException {
+    // to make sure no two files are the same
+    Set<INodeFile> si = new HashSet<>();
+    final INodeFile targetINode = targetIIP.getLastINode().asFile();
+    final INodeDirectory targetParent = targetINode.getParent();
     // now check the srcs
-    boolean endSrc = false; // final src file doesn't have to have full end block
-    for(int i=0; i< srcs.length; i++) {
-      String src = srcs[i];
-      if(i== srcs.length-1)
-        endSrc=true;
-
-      final INodeFile srcInode = INodeFile.valueOf(fsd.getINode4Write(src), src);
-      if(src.isEmpty()
-          || srcInode.isUnderConstruction()
-          || srcInode.numBlocks() == 0) {
-        throw new HadoopIllegalArgumentException("concat: source file " + src
-            + " is invalid or empty or underConstruction");
+    for(String src : srcs) {
+      final INodesInPath iip = fsd.getINodesInPath4Write(src);
+      // permission check for srcs
+      if (pc != null) {
+        fsd.checkPathAccess(pc, iip, FsAction.READ); // read the file
+        fsd.checkParentAccess(pc, iip, FsAction.WRITE); // for delete
       }
-
-      // check replication and blocks size
-      if(repl != srcInode.getBlockReplication()) {
-        throw new HadoopIllegalArgumentException("concat: the source file "
-            + src + " and the target file " + target
-            + " should have the same replication: source replication is "
-            + srcInode.getBlockReplication()
-            + " but target replication is " + repl);
+      final INode srcINode = iip.getLastINode();
+      final INodeFile srcINodeFile = INodeFile.valueOf(srcINode, src);
+      // make sure the src file and the target file are in the same dir
+      if (srcINodeFile.getParent() != targetParent) {
+        throw new HadoopIllegalArgumentException("Source file " + src
+            + " is not in the same directory with the target "
+            + targetIIP.getPath());
       }
-
-      //boolean endBlock=false;
-      // verify that all the blocks are of the same length as target
-      // should be enough to check the end blocks
-      final BlockInfo[] srcBlocks = srcInode.getBlocks();
-      int idx = srcBlocks.length-1;
-      if(endSrc)
-        idx = srcBlocks.length-2; // end block of endSrc is OK not to be full
-      if(idx >= 0 && srcBlocks[idx].getNumBytes() != blockSize) {
-        throw new HadoopIllegalArgumentException("concat: the source file "
-            + src + " and the target file " + target
-            + " should have the same blocks sizes: target block size is "
-            + blockSize + " but the size of source block " + idx + " is "
-            + srcBlocks[idx].getNumBytes());
+      // make sure all the source files are not in snapshot
+      if (srcINode.isInLatestSnapshot(iip.getLatestSnapshotId())) {
+        throw new SnapshotException("Concat: the source file " + src
+            + " is in snapshot");
       }
-
-      si.add(srcInode);
+      // check if the file has other references.
+      if (srcINode.isReference() && ((INodeReference.WithCount)
+          srcINode.asReference().getReferredINode()).getReferenceCount() > 1) {
+        throw new SnapshotException("Concat: the source file " + src
+            + " is referred by some other reference in some snapshot.");
+      }
+      if (srcINode == targetINode) {
+        throw new HadoopIllegalArgumentException("concat: the src file " + src
+            + " is the same with the target file " + targetIIP.getPath());
+      }
+      if(srcINodeFile.isUnderConstruction() || srcINodeFile.numBlocks() == 0) {
+        throw new HadoopIllegalArgumentException("concat: source file " + src
+            + " is invalid or empty or underConstruction");
+      }
+      si.add(srcINodeFile);
     }
 
     // make sure no two files are the same
-    if(si.size() < srcs.length+1) { // trg + srcs
+    if(si.size() < srcs.length) {
       // it means at least two files are the same
       throw new HadoopIllegalArgumentException(
           "concat: at least two of the source files are the same");
     }
+    return si.toArray(new INodeFile[si.size()]);
+  }
 
-    if(NameNode.stateChangeLog.isDebugEnabled()) {
-      NameNode.stateChangeLog.debug("DIR* NameSystem.concat: " +
-          Arrays.toString(srcs) + " to " + target);
+  private static long computeQuotaDelta(INodeFile target, INodeFile[] srcList) {
+    long delta = 0;
+    short targetRepl = target.getBlockReplication();
+    for (INodeFile src : srcList) {
+      if (targetRepl != src.getBlockReplication()) {
+        delta += src.computeFileSize() *
+            (targetRepl - src.getBlockReplication());
+      }
     }
+    return delta;
+  }
 
-    long timestamp = now();
-    fsd.writeLock();
-    try {
-      unprotectedConcat(fsd, target, srcs, timestamp);
-    } finally {
-      fsd.writeUnlock();
+  private static void verifyQuota(FSDirectory fsd, INodesInPath targetIIP,
+      long delta) throws QuotaExceededException {
+    if (!fsd.getFSNamesystem().isImageLoaded() || fsd.shouldSkipQuotaChecks()) {
+      // Do not check quota if editlog is still being processed
+      return;
     }
-    fsd.getEditLog().logConcat(target, srcs, timestamp, logRetryCache);
-    return fsd.getAuditFileInfo(trgIip);
+    FSDirectory.verifyQuota(targetIIP, targetIIP.length() - 1, 0, delta, null);
   }
 
   /**
    * Concat all the blocks from srcs to trg and delete the srcs files
    * @param fsd FSDirectory
-   * @param target target file to move the blocks to
-   * @param srcs list of file to move the blocks from
    */
-  static void unprotectedConcat(
-    FSDirectory fsd, String target, String[] srcs, long timestamp)
-    throws IOException {
+  static void unprotectedConcat(FSDirectory fsd, INodesInPath targetIIP,
+      INodeFile[] srcList, long timestamp) throws IOException {
     assert fsd.hasWriteLock();
     if (NameNode.stateChangeLog.isDebugEnabled()) {
-      NameNode.stateChangeLog.debug("DIR* FSNamesystem.concat to "+target);
+      NameNode.stateChangeLog.debug("DIR* FSNamesystem.concat to "
+          + targetIIP.getPath());
     }
-    // do the move
-
-    final INodesInPath trgIIP = fsd.getINodesInPath4Write(target, true);
-    final INodeFile trgInode = trgIIP.getLastINode().asFile();
-    INodeDirectory trgParent = trgIIP.getINode(-2).asDirectory();
-    final int trgLatestSnapshot = trgIIP.getLatestSnapshotId();
-
-    final INodeFile [] allSrcInodes = new INodeFile[srcs.length];
-    for(int i = 0; i < srcs.length; i++) {
-      final INodesInPath iip = fsd.getINodesInPath4Write(srcs[i]);
-      final int latest = iip.getLatestSnapshotId();
-      final INode inode = iip.getLastINode();
-
-      // check if the file in the latest snapshot
-      if (inode.isInLatestSnapshot(latest)) {
-        throw new SnapshotException("Concat: the source file " + srcs[i]
-            + " is in snapshot " + latest);
-      }
 
-      // check if the file has other references.
-      if (inode.isReference() && ((INodeReference.WithCount)
-          inode.asReference().getReferredINode()).getReferenceCount() > 1) {
-        throw new SnapshotException("Concat: the source file " + srcs[i]
-            + " is referred by some other reference in some snapshot.");
-      }
+    final INodeFile trgInode = targetIIP.getLastINode().asFile();
+    long delta = computeQuotaDelta(trgInode, srcList);
+    verifyQuota(fsd, targetIIP, delta);
 
-      allSrcInodes[i] = inode.asFile();
-    }
-    trgInode.concatBlocks(allSrcInodes);
+    // the target file can be included in a snapshot
+    trgInode.recordModification(targetIIP.getLatestSnapshotId());
+    INodeDirectory trgParent = targetIIP.getINode(-2).asDirectory();
+    trgInode.concatBlocks(srcList);
 
     // since we are in the same dir - we can use same parent to remove files
     int count = 0;
-    for(INodeFile nodeToRemove: allSrcInodes) {
-      if(nodeToRemove == null) continue;
-
-      nodeToRemove.setBlocks(null);
-      trgParent.removeChild(nodeToRemove, trgLatestSnapshot);
-      fsd.getINodeMap().remove(nodeToRemove);
-      count++;
+    for (INodeFile nodeToRemove : srcList) {
+      if(nodeToRemove != null) {
+        nodeToRemove.setBlocks(null);
+        nodeToRemove.getParent().removeChild(nodeToRemove);
+        fsd.getINodeMap().remove(nodeToRemove);
+        count++;
+      }
     }
 
-    trgInode.setModificationTime(timestamp, trgLatestSnapshot);
-    trgParent.updateModificationTime(timestamp, trgLatestSnapshot);
+    trgInode.setModificationTime(timestamp, targetIIP.getLatestSnapshotId());
+    trgParent.updateModificationTime(timestamp, targetIIP.getLatestSnapshotId());
     // update quota on the parent directory ('count' files removed, 0 space)
-    FSDirectory.unprotectedUpdateCount(trgIIP, trgIIP.length() - 1, -count, 0);
+    FSDirectory.unprotectedUpdateCount(targetIIP, targetIIP.length() - 1,
+        -count, delta);
   }
 }

http://git-wip-us.apache.org/repos/asf/hadoop/blob/2848db81/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSDirectory.java
----------------------------------------------------------------------
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSDirectory.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSDirectory.java
index c171448..c012847 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSDirectory.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSDirectory.java
@@ -452,7 +452,7 @@ public class FSDirectory implements Closeable {
       Preconditions.checkState(fileINode.isUnderConstruction());
 
       // check quota limits and updated space consumed
-      updateCount(inodesInPath, 0, fileINode.getBlockDiskspace(), true);
+      updateCount(inodesInPath, 0, fileINode.getPreferredBlockDiskspace(), true);
 
       // associate new last block for the file
       BlockInfoUnderConstruction blockInfo =
@@ -508,7 +508,7 @@ public class FSDirectory implements Closeable {
     }
 
     // update space consumed
-    updateCount(iip, 0, -fileNode.getBlockDiskspace(), true);
+    updateCount(iip, 0, -fileNode.getPreferredBlockDiskspace(), true);
     return true;
   }
 

http://git-wip-us.apache.org/repos/asf/hadoop/blob/2848db81/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSEditLog.java
----------------------------------------------------------------------
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSEditLog.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSEditLog.java
index 144be37..3c7eae4 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSEditLog.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSEditLog.java
@@ -34,10 +34,10 @@ import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.Options;
+import org.apache.hadoop.fs.XAttr;
 import org.apache.hadoop.fs.permission.AclEntry;
 import org.apache.hadoop.fs.permission.FsPermission;
 import org.apache.hadoop.fs.permission.PermissionStatus;
-import org.apache.hadoop.fs.XAttr;
 import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.apache.hadoop.hdfs.protocol.Block;
 import org.apache.hadoop.hdfs.protocol.CacheDirectiveInfo;
@@ -52,9 +52,11 @@ import org.apache.hadoop.hdfs.server.common.StorageInfo;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.AddBlockOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.AddCacheDirectiveInfoOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.AddCachePoolOp;
+import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.AddCloseOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.AddOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.AllocateBlockIdOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.AllowSnapshotOp;
+import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.AppendOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.CancelDelegationTokenOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.CloseOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.ConcatDeleteOp;
@@ -76,6 +78,7 @@ import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.RenameOldOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.RenameOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.RenameSnapshotOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.RenewDelegationTokenOp;
+import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.RollingUpgradeOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.SetAclOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.SetGenstampV1Op;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.SetGenstampV2Op;
@@ -90,7 +93,6 @@ import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.TimesOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.TruncateOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.UpdateBlocksOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.UpdateMasterKeyOp;
-import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.RollingUpgradeOp;
 import org.apache.hadoop.hdfs.server.namenode.JournalSet.JournalAndStream;
 import org.apache.hadoop.hdfs.server.namenode.metrics.NameNodeMetrics;
 import org.apache.hadoop.hdfs.server.protocol.NamenodeRegistration;
@@ -702,7 +704,19 @@ public class FSEditLog implements LogsPurgeable {
       op.setRpcCallId(Server.getCallId());
     }
   }
-  
+
+  public void logAppendFile(String path, INodeFile file, boolean newBlock,
+      boolean toLogRpcIds) {
+    FileUnderConstructionFeature uc = file.getFileUnderConstructionFeature();
+    assert uc != null;
+    AppendOp op = AppendOp.getInstance(cache.get()).setPath(path)
+        .setClientName(uc.getClientName())
+        .setClientMachine(uc.getClientMachine())
+        .setNewBlock(newBlock);
+    logRpcIds(op, toLogRpcIds);
+    logEdit(op);
+  }
+
   /** 
    * Add open lease record to edit log. 
    * Records the block locations of the last block.

http://git-wip-us.apache.org/repos/asf/hadoop/blob/2848db81/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSEditLogLoader.java
----------------------------------------------------------------------
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSEditLogLoader.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSEditLogLoader.java
index 322e18c..7cb6486 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSEditLogLoader.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSEditLogLoader.java
@@ -34,6 +34,7 @@ import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.fs.XAttrSetFlag;
+import org.apache.hadoop.hdfs.protocol.LocatedBlock;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockStoragePolicySuite;
 import org.apache.hadoop.hdfs.protocol.Block;
 import org.apache.hadoop.hdfs.protocol.CacheDirectiveInfo;
@@ -41,7 +42,6 @@ import org.apache.hadoop.hdfs.protocol.HdfsConstants;
 import org.apache.hadoop.hdfs.protocol.HdfsFileStatus;
 import org.apache.hadoop.hdfs.protocol.LastBlockWithStatus;
 import org.apache.hadoop.hdfs.protocol.LayoutVersion;
-import org.apache.hadoop.hdfs.protocol.LocatedBlock;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfo;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoUnderConstruction;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.RollingUpgradeStartupOption;
@@ -53,6 +53,7 @@ import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.AddCachePoolOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.AddCloseOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.AllocateBlockIdOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.AllowSnapshotOp;
+import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.AppendOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.BlockListUpdatingOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.CancelDelegationTokenOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.ClearNSQuotaOp;
@@ -68,6 +69,7 @@ import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.ModifyCachePoolOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.ReassignLeaseOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.RemoveCacheDirectiveInfoOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.RemoveCachePoolOp;
+import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.RemoveXAttrOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.RenameOldOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.RenameOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.RenameSnapshotOp;
@@ -83,7 +85,6 @@ import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.SetQuotaOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.SetReplicationOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.SetStoragePolicyOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.SetXAttrOp;
-import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.RemoveXAttrOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.SymlinkOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.TimesOp;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.UpdateBlocksOp;
@@ -325,22 +326,22 @@ public class FSEditLogLoader {
       LOG.trace("replaying edit log: " + op);
     }
     final boolean toAddRetryCache = fsNamesys.hasRetryCache() && op.hasRpcIds();
-    
+
     switch (op.opCode) {
     case OP_ADD: {
       AddCloseOp addCloseOp = (AddCloseOp)op;
       final String path =
           renameReservedPathsOnUpgrade(addCloseOp.path, logVersion);
-      if (LOG.isDebugEnabled()) {
-        LOG.debug(op.opCode + ": " + path +
+      if (FSNamesystem.LOG.isDebugEnabled()) {
+        FSNamesystem.LOG.debug(op.opCode + ": " + path +
             " numblocks : " + addCloseOp.blocks.length +
             " clientHolder " + addCloseOp.clientName +
             " clientMachine " + addCloseOp.clientMachine);
       }
-      // There three cases here:
+      // There are 3 cases here:
       // 1. OP_ADD to create a new file
       // 2. OP_ADD to update file blocks
-      // 3. OP_ADD to open file for append
+      // 3. OP_ADD to open file for append (old append)
 
       // See if the file already exists (persistBlocks call)
       INodesInPath iip = fsDir.getINodesInPath(path, true);
@@ -383,19 +384,17 @@ public class FSEditLogLoader {
           fsNamesys.addCacheEntryWithPayload(addCloseOp.rpcClientId,
               addCloseOp.rpcCallId, stat);
         }
-      } else { // This is OP_ADD on an existing file
+      } else { // This is OP_ADD on an existing file (old append)
         if (!oldFile.isUnderConstruction()) {
           // This is case 3: a call to append() on an already-closed file.
           if (FSNamesystem.LOG.isDebugEnabled()) {
             FSNamesystem.LOG.debug("Reopening an already-closed file " +
                 "for append");
           }
-          // Note we do not replace the INodeFile when converting it to
-          // under-construction
-          LocatedBlock lb = fsNamesys.prepareFileForWrite(path, iip,
-              addCloseOp.clientName, addCloseOp.clientMachine, false, false);
-          
-          // add the op into retry cache is necessary
+          LocatedBlock lb = fsNamesys.prepareFileForAppend(path, iip,
+              addCloseOp.clientName, addCloseOp.clientMachine, false, false,
+              false);
+          // add the op into retry cache if necessary
           if (toAddRetryCache) {
             HdfsFileStatus stat = FSDirStatAndListingOp.createFileStatus(
                 fsNamesys.dir,
@@ -453,6 +452,34 @@ public class FSEditLogLoader {
       }
       break;
     }
+    case OP_APPEND: {
+      AppendOp appendOp = (AppendOp) op;
+      final String path = renameReservedPathsOnUpgrade(appendOp.path,
+          logVersion);
+      if (FSNamesystem.LOG.isDebugEnabled()) {
+        FSNamesystem.LOG.debug(op.opCode + ": " + path +
+            " clientName " + appendOp.clientName +
+            " clientMachine " + appendOp.clientMachine +
+            " newBlock " + appendOp.newBlock);
+      }
+      INodesInPath iip = fsDir.getINodesInPath4Write(path);
+      INodeFile file = INodeFile.valueOf(iip.getLastINode(), path);
+      if (!file.isUnderConstruction()) {
+        LocatedBlock lb = fsNamesys.prepareFileForAppend(path, iip,
+            appendOp.clientName, appendOp.clientMachine, appendOp.newBlock,
+            false, false);
+        // add the op into retry cache if necessary
+        if (toAddRetryCache) {
+          HdfsFileStatus stat = FSDirStatAndListingOp.createFileStatus(
+              fsNamesys.dir, HdfsFileStatus.EMPTY_NAME, file,
+              BlockStoragePolicySuite.ID_UNSPECIFIED,
+              Snapshot.CURRENT_STATE_ID, false, iip);
+          fsNamesys.addCacheEntryWithPayload(appendOp.rpcClientId,
+              appendOp.rpcCallId, new LastBlockWithStatus(lb, stat));
+        }
+      }
+      break;
+    }
     case OP_UPDATE_BLOCKS: {
       UpdateBlocksOp updateOp = (UpdateBlocksOp)op;
       final String path =
@@ -499,7 +526,14 @@ public class FSEditLogLoader {
         srcs[i] =
             renameReservedPathsOnUpgrade(concatDeleteOp.srcs[i], logVersion);
       }
-      FSDirConcatOp.unprotectedConcat(fsDir, trg, srcs, concatDeleteOp.timestamp);
+      INodesInPath targetIIP = fsDir.getINodesInPath4Write(trg);
+      INodeFile[] srcFiles = new INodeFile[srcs.length];
+      for (int i = 0; i < srcs.length; i++) {
+        INodesInPath srcIIP = fsDir.getINodesInPath4Write(srcs[i]);
+        srcFiles[i] = srcIIP.getLastINode().asFile();
+      }
+      FSDirConcatOp.unprotectedConcat(fsDir, targetIIP, srcFiles,
+          concatDeleteOp.timestamp);
       
       if (toAddRetryCache) {
         fsNamesys.addCacheEntry(concatDeleteOp.rpcClientId,

http://git-wip-us.apache.org/repos/asf/hadoop/blob/2848db81/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSEditLogOp.java
----------------------------------------------------------------------
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSEditLogOp.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSEditLogOp.java
index 9424156..1629d80 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSEditLogOp.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSEditLogOp.java
@@ -18,6 +18,7 @@
 package org.apache.hadoop.hdfs.server.namenode;
 
 import static org.apache.hadoop.hdfs.server.namenode.FSEditLogOpCodes.OP_ADD;
+import static org.apache.hadoop.hdfs.server.namenode.FSEditLogOpCodes.OP_APPEND;
 import static org.apache.hadoop.hdfs.server.namenode.FSEditLogOpCodes.OP_ADD_BLOCK;
 import static org.apache.hadoop.hdfs.server.namenode.FSEditLogOpCodes.OP_ADD_CACHE_DIRECTIVE;
 import static org.apache.hadoop.hdfs.server.namenode.FSEditLogOpCodes.OP_ADD_CACHE_POOL;
@@ -207,6 +208,7 @@ public abstract class FSEditLogOp {
       inst.put(OP_SET_XATTR, new SetXAttrOp());
       inst.put(OP_REMOVE_XATTR, new RemoveXAttrOp());
       inst.put(OP_SET_STORAGE_POLICY, new SetStoragePolicyOp());
+      inst.put(OP_APPEND, new AppendOp());
     }
     
     public FSEditLogOp get(FSEditLogOpCodes opcode) {
@@ -428,7 +430,7 @@ public abstract class FSEditLogOp {
     private AddCloseOp(FSEditLogOpCodes opCode) {
       super(opCode);
       storagePolicyId = BlockStoragePolicySuite.ID_UNSPECIFIED;
-      assert(opCode == OP_ADD || opCode == OP_CLOSE);
+      assert(opCode == OP_ADD || opCode == OP_CLOSE || opCode == OP_APPEND);
     }
 
     @Override
@@ -770,7 +772,7 @@ public abstract class FSEditLogOp {
     }
 
     static AddOp getInstance(OpInstanceCache cache) {
-      return (AddOp)cache.get(OP_ADD);
+      return (AddOp) cache.get(OP_ADD);
     }
 
     @Override
@@ -788,7 +790,7 @@ public abstract class FSEditLogOp {
   }
 
   /**
-   * Although {@link ClientProtocol#appendFile} may also log a close op, we do
+   * Although {@link ClientProtocol#append} may also log a close op, we do
    * not need to record the rpc ids here since a successful appendFile op will
    * finally log an AddOp.
    */
@@ -814,6 +816,97 @@ public abstract class FSEditLogOp {
       return builder.toString();
     }
   }
+
+  static class AppendOp extends FSEditLogOp {
+    String path;
+    String clientName;
+    String clientMachine;
+    boolean newBlock;
+
+    private AppendOp() {
+      super(OP_APPEND);
+    }
+
+    static AppendOp getInstance(OpInstanceCache cache) {
+      return (AppendOp) cache.get(OP_APPEND);
+    }
+
+    AppendOp setPath(String path) {
+      this.path = path;
+      return this;
+    }
+
+    AppendOp setClientName(String clientName) {
+      this.clientName = clientName;
+      return this;
+    }
+
+    AppendOp setClientMachine(String clientMachine) {
+      this.clientMachine = clientMachine;
+      return this;
+    }
+
+    AppendOp setNewBlock(boolean newBlock) {
+      this.newBlock = newBlock;
+      return this;
+    }
+
+    @Override
+    public String toString() {
+      StringBuilder builder = new StringBuilder();
+      builder.append("AppendOp ");
+      builder.append("[path=").append(path);
+      builder.append(", clientName=").append(clientName);
+      builder.append(", clientMachine=").append(clientMachine);
+      builder.append(", newBlock=").append(newBlock).append("]");
+      return builder.toString();
+    }
+
+    @Override
+    void resetSubFields() {
+      this.path = null;
+      this.clientName = null;
+      this.clientMachine = null;
+      this.newBlock = false;
+    }
+
+    @Override
+    void readFields(DataInputStream in, int logVersion) throws IOException {
+      this.path = FSImageSerialization.readString(in);
+      this.clientName = FSImageSerialization.readString(in);
+      this.clientMachine = FSImageSerialization.readString(in);
+      this.newBlock = FSImageSerialization.readBoolean(in);
+      readRpcIds(in, logVersion);
+    }
+
+    @Override
+    public void writeFields(DataOutputStream out) throws IOException {
+      FSImageSerialization.writeString(path, out);
+      FSImageSerialization.writeString(clientName, out);
+      FSImageSerialization.writeString(clientMachine, out);
+      FSImageSerialization.writeBoolean(newBlock, out);
+      writeRpcIds(rpcClientId, rpcCallId, out);
+    }
+
+    @Override
+    protected void toXml(ContentHandler contentHandler) throws SAXException {
+      XMLUtils.addSaxString(contentHandler, "PATH", path);
+      XMLUtils.addSaxString(contentHandler, "CLIENT_NAME", clientName);
+      XMLUtils.addSaxString(contentHandler, "CLIENT_MACHINE", clientMachine);
+      XMLUtils.addSaxString(contentHandler, "NEWBLOCK",
+          Boolean.toString(newBlock));
+      appendRpcIdsToXml(contentHandler, rpcClientId, rpcCallId);
+    }
+
+    @Override
+    void fromXml(Stanza st) throws InvalidXmlException {
+      this.path = st.getValue("PATH");
+      this.clientName = st.getValue("CLIENT_NAME");
+      this.clientMachine = st.getValue("CLIENT_MACHINE");
+      this.newBlock = Boolean.parseBoolean(st.getValue("NEWBLOCK"));
+      readRpcIdsFromXml(st);
+    }
+  }
   
   static class AddBlockOp extends FSEditLogOp {
     private String path;
@@ -1643,7 +1736,7 @@ public abstract class FSEditLogOp {
    * {@link ClientProtocol#updateBlockForPipeline},
    * {@link ClientProtocol#recoverLease}, {@link ClientProtocol#addBlock}) or
    * already bound with other editlog op which records rpc ids (
-   * {@link ClientProtocol#startFile}). Thus no need to record rpc ids here.
+   * {@link ClientProtocol#create}). Thus no need to record rpc ids here.
    */
   static class SetGenstampV1Op extends FSEditLogOp {
     long genStampV1;

http://git-wip-us.apache.org/repos/asf/hadoop/blob/2848db81/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSEditLogOpCodes.java
----------------------------------------------------------------------
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSEditLogOpCodes.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSEditLogOpCodes.java
index 468e048..6cd1617 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSEditLogOpCodes.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSEditLogOpCodes.java
@@ -74,6 +74,7 @@ public enum FSEditLogOpCodes {
   OP_REMOVE_XATTR               ((byte) 44),
   OP_SET_STORAGE_POLICY         ((byte) 45),
   OP_TRUNCATE                   ((byte) 46),
+  OP_APPEND                     ((byte) 47),
 
   // Note that the current range of the valid OP code is 0~127
   OP_INVALID                    ((byte) -1);

http://git-wip-us.apache.org/repos/asf/hadoop/blob/2848db81/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java
----------------------------------------------------------------------
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java
index fae1641..ebdec1b 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java
@@ -250,6 +250,7 @@ import org.apache.hadoop.hdfs.server.protocol.NamenodeRegistration;
 import org.apache.hadoop.hdfs.server.protocol.NamespaceInfo;
 import org.apache.hadoop.hdfs.server.protocol.StorageReceivedDeletedBlocks;
 import org.apache.hadoop.hdfs.server.protocol.StorageReport;
+import org.apache.hadoop.io.EnumSetWritable;
 import org.apache.hadoop.io.IOUtils;
 import org.apache.hadoop.io.Text;
 import org.apache.hadoop.ipc.RetriableException;
@@ -2586,12 +2587,12 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
    * <p>
    * 
    * For description of parameters and exceptions thrown see
-   * {@link ClientProtocol#append(String, String)}
-   * 
+   * {@link ClientProtocol#append(String, String, EnumSetWritable)}
+   *
    * @return the last block locations if the block is partial or null otherwise
    */
   private LocatedBlock appendFileInternal(FSPermissionChecker pc,
-      INodesInPath iip, String holder, String clientMachine,
+      INodesInPath iip, String holder, String clientMachine, boolean newBlock,
       boolean logRetryCache) throws IOException {
     assert hasWriteLock();
     // Verify that the destination does not exist as a directory already.
@@ -2613,7 +2614,6 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
       INodeFile myFile = INodeFile.valueOf(inode, src, true);
       final BlockStoragePolicy lpPolicy =
           blockManager.getStoragePolicy("LAZY_PERSIST");
-
       if (lpPolicy != null &&
           lpPolicy.getId() == myFile.getStoragePolicyID()) {
         throw new UnsupportedOperationException(
@@ -2629,8 +2629,8 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
         throw new IOException("append: lastBlock=" + lastBlock +
             " of src=" + src + " is not sufficiently replicated yet.");
       }
-      return prepareFileForWrite(src, iip, holder, clientMachine, true,
-              logRetryCache);
+      return prepareFileForAppend(src, iip, holder, clientMachine, newBlock,
+          true, logRetryCache);
     } catch (IOException ie) {
       NameNode.stateChangeLog.warn("DIR* NameSystem.append: " +ie.getMessage());
       throw ie;
@@ -2644,6 +2644,7 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
    * @param src path to the file
    * @param leaseHolder identifier of the lease holder on this file
    * @param clientMachine identifier of the client machine
+   * @param newBlock if the data is appended to a new block
    * @param writeToEditLog whether to persist this change to the edit log
    * @param logRetryCache whether to record RPC ids in editlog for retry cache
    *                      rebuilding
@@ -2651,26 +2652,34 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
    * @throws UnresolvedLinkException
    * @throws IOException
    */
-  LocatedBlock prepareFileForWrite(String src, INodesInPath iip,
-      String leaseHolder, String clientMachine, boolean writeToEditLog,
-      boolean logRetryCache) throws IOException {
+  LocatedBlock prepareFileForAppend(String src, INodesInPath iip,
+      String leaseHolder, String clientMachine, boolean newBlock,
+      boolean writeToEditLog, boolean logRetryCache) throws IOException {
     final INodeFile file = iip.getLastINode().asFile();
     file.recordModification(iip.getLatestSnapshotId());
     file.toUnderConstruction(leaseHolder, clientMachine);
 
     leaseManager.addLease(
         file.getFileUnderConstructionFeature().getClientName(), src);
-    
-    LocatedBlock ret =
-        blockManager.convertLastBlockToUnderConstruction(file, 0);
-    if (ret != null) {
-      // update the quota: use the preferred block size for UC block
-      final long diff = file.getPreferredBlockSize() - ret.getBlockSize();
-      dir.updateSpaceConsumed(iip, 0, diff * file.getBlockReplication());
+
+    LocatedBlock ret = null;
+    if (!newBlock) {
+      ret = blockManager.convertLastBlockToUnderConstruction(file, 0);
+      if (ret != null) {
+        // update the quota: use the preferred block size for UC block
+        final long diff = file.getPreferredBlockSize() - ret.getBlockSize();
+        dir.updateSpaceConsumed(iip, 0, diff * file.getBlockReplication());
+      }
+    } else {
+      BlockInfo lastBlock = file.getLastBlock();
+      if (lastBlock != null) {
+        ExtendedBlock blk = new ExtendedBlock(this.getBlockPoolId(), lastBlock);
+        ret = new LocatedBlock(blk, new DatanodeInfo[0]);
+      }
     }
 
     if (writeToEditLog) {
-      getEditLog().logOpenFile(src, file, false, logRetryCache);
+      getEditLog().logAppendFile(src, file, newBlock, logRetryCache);
     }
     return ret;
   }
@@ -2805,11 +2814,12 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
   /**
    * Append to an existing file in the namespace.
    */
-  LastBlockWithStatus appendFile(
-      String src, String holder, String clientMachine, boolean logRetryCache)
+  LastBlockWithStatus appendFile(String src, String holder,
+      String clientMachine, EnumSet<CreateFlag> flag, boolean logRetryCache)
       throws IOException {
     try {
-      return appendFileInt(src, holder, clientMachine, logRetryCache);
+      return appendFileInt(src, holder, clientMachine,
+          flag.contains(CreateFlag.NEW_BLOCK), logRetryCache);
     } catch (AccessControlException e) {
       logAuditEvent(false, "append", src);
       throw e;
@@ -2817,7 +2827,8 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
   }
 
   private LastBlockWithStatus appendFileInt(final String srcArg, String holder,
-      String clientMachine, boolean logRetryCache) throws IOException {
+      String clientMachine, boolean newBlock, boolean logRetryCache)
+      throws IOException {
     String src = srcArg;
     if (NameNode.stateChangeLog.isDebugEnabled()) {
       NameNode.stateChangeLog.debug("DIR* NameSystem.appendFile: src=" + src
@@ -2836,7 +2847,8 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
       checkNameNodeSafeMode("Cannot append to file" + src);
       src = dir.resolvePath(pc, src, pathComponents);
       final INodesInPath iip = dir.getINodesInPath4Write(src);
-      lb = appendFileInternal(pc, iip, holder, clientMachine, logRetryCache);
+      lb = appendFileInternal(pc, iip, holder, clientMachine, newBlock,
+          logRetryCache);
       stat = FSDirStatAndListingOp.getFileInfo(dir, src, false,
           FSDirectory.isReservedRawName(srcArg), true);
     } catch (StandbyException se) {

http://git-wip-us.apache.org/repos/asf/hadoop/blob/2848db81/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/INodeFile.java
----------------------------------------------------------------------
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/INodeFile.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/INodeFile.java
index e871bdc..cbcdac9 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/INodeFile.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/INodeFile.java
@@ -412,7 +412,7 @@ public class INodeFile extends INodeWithAdditionalFields
   }
 
   /** @return the diskspace required for a full block. */
-  final long getBlockDiskspace() {
+  final long getPreferredBlockDiskspace() {
     return getPreferredBlockSize() * getBlockReplication();
   }
 

http://git-wip-us.apache.org/repos/asf/hadoop/blob/2848db81/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/InotifyFSEditLogOpTranslator.java
----------------------------------------------------------------------
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/InotifyFSEditLogOpTranslator.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/InotifyFSEditLogOpTranslator.java
index f265340..5345b46 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/InotifyFSEditLogOpTranslator.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/InotifyFSEditLogOpTranslator.java
@@ -65,6 +65,10 @@ public class InotifyFSEditLogOpTranslator {
       FSEditLogOp.CloseOp cOp = (FSEditLogOp.CloseOp) op;
       return new EventBatch(op.txid, new Event[] {
           new Event.CloseEvent(cOp.path, getSize(cOp), cOp.mtime) });
+    case OP_APPEND:
+      FSEditLogOp.AppendOp appendOp = (FSEditLogOp.AppendOp) op;
+      return new EventBatch(op.txid, new Event[] {new Event.AppendEvent
+          .Builder().path(appendOp.path).newBlock(appendOp.newBlock).build()});
     case OP_SET_REPLICATION:
       FSEditLogOp.SetReplicationOp setRepOp = (FSEditLogOp.SetReplicationOp) op;
       return new EventBatch(op.txid,

http://git-wip-us.apache.org/repos/asf/hadoop/blob/2848db81/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNodeLayoutVersion.java
----------------------------------------------------------------------
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNodeLayoutVersion.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNodeLayoutVersion.java
index d742c6d..848fa33 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNodeLayoutVersion.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNodeLayoutVersion.java
@@ -70,7 +70,8 @@ public class NameNodeLayoutVersion {
       "creating file with overwrite"),
     XATTRS_NAMESPACE_EXT(-59, "Increase number of xattr namespaces"),
     BLOCK_STORAGE_POLICY(-60, "Block Storage policy"),
-    TRUNCATE(-61, "Truncate");
+    TRUNCATE(-61, "Truncate"),
+    APPEND_NEW_BLOCK(-62, "Support appending to new block");
 
     private final FeatureInfo info;