diff --git a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
index 1bbe91c625b..7a333c40428 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
+++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
@@ -65,14 +65,18 @@ Trunk (unreleased changes)
 
     HDFS-2480. Separate datatypes for NamenodeProtocol. (suresh)
 
-	HDFS-2181 Separate HDFS Client wire protocol data types (sanjay)
+    HDFS-2181 Separate HDFS Client wire protocol data types (sanjay)
 
     HDFS-2294. Download of commons-daemon TAR should not be under target (tucu)
 
-    HDFS-2322. the build fails in Windows because commons-daemon TAR cannot be fetched. (tucu)
+    HDFS-2322. the build fails in Windows because commons-daemon TAR cannot be 
+    fetched. (tucu)
 
     HDFS-2427. Change the default permission in webhdfs to 755 and add range
-    check/validation for all parameters.  (szetszwo)
+    check/validation for all parameters. (szetszwo)
+
+    HDFS-2489. Move Finalize and Register to separate file out of
+    DatanodeCommand.java. (suresh)
 
   BUG FIXES
     HDFS-2287. TestParallelRead has a small off-by-one bug. (todd)
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/DatanodeManager.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/DatanodeManager.java
index e0c2de955a7..3cfc9010977 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/DatanodeManager.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/DatanodeManager.java
@@ -60,6 +60,7 @@ import org.apache.hadoop.hdfs.server.protocol.DatanodeCommand;
 import org.apache.hadoop.hdfs.server.protocol.DatanodeProtocol;
 import org.apache.hadoop.hdfs.server.protocol.DatanodeRegistration;
 import org.apache.hadoop.hdfs.server.protocol.DisallowedDatanodeException;
+import org.apache.hadoop.hdfs.server.protocol.RegisterCommand;
 import org.apache.hadoop.hdfs.util.CyclicIteration;
 import org.apache.hadoop.ipc.Server;
 import org.apache.hadoop.net.CachedDNSToSwitchMapping;
@@ -859,7 +860,7 @@ public class DatanodeManager {
         try {
           nodeinfo = getDatanode(nodeReg);
         } catch(UnregisteredNodeException e) {
-          return new DatanodeCommand[]{DatanodeCommand.REGISTER};
+          return new DatanodeCommand[]{RegisterCommand.REGISTER};
         }
         
         // Check if this datanode should actually be shutdown instead. 
@@ -869,7 +870,7 @@ public class DatanodeManager {
         }
          
         if (nodeinfo == null || !nodeinfo.isAlive) {
-          return new DatanodeCommand[]{DatanodeCommand.REGISTER};
+          return new DatanodeCommand[]{RegisterCommand.REGISTER};
         }
 
         heartbeatManager.updateHeartbeat(nodeinfo, capacity, dfsUsed,
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNode.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNode.java
index 82f28c71332..61c1cbec18f 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNode.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNode.java
@@ -151,6 +151,7 @@ import org.apache.hadoop.hdfs.server.protocol.DatanodeCommand;
 import org.apache.hadoop.hdfs.server.protocol.DatanodeProtocol;
 import org.apache.hadoop.hdfs.server.protocol.DatanodeRegistration;
 import org.apache.hadoop.hdfs.server.protocol.DisallowedDatanodeException;
+import org.apache.hadoop.hdfs.server.protocol.FinalizeCommand;
 import org.apache.hadoop.hdfs.server.protocol.InterDatanodeProtocol;
 import org.apache.hadoop.hdfs.server.protocol.KeyUpdateCommand;
 import org.apache.hadoop.hdfs.server.protocol.NamespaceInfo;
@@ -1418,7 +1419,7 @@ public class DataNode extends Configured
         }
         break;
       case DatanodeProtocol.DNA_FINALIZE:
-        storage.finalizeUpgrade(((DatanodeCommand.Finalize) cmd)
+        storage.finalizeUpgrade(((FinalizeCommand) cmd)
             .getBlockPoolId());
         break;
       case UpgradeCommand.UC_ACTION_START_UPGRADE:
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNodeRpcServer.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNodeRpcServer.java
index be0be103417..9e4a920fcb1 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNodeRpcServer.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNodeRpcServer.java
@@ -69,6 +69,7 @@ import org.apache.hadoop.hdfs.server.protocol.BlocksWithLocations;
 import org.apache.hadoop.hdfs.server.protocol.DatanodeCommand;
 import org.apache.hadoop.hdfs.server.protocol.DatanodeProtocol;
 import org.apache.hadoop.hdfs.server.protocol.DatanodeRegistration;
+import org.apache.hadoop.hdfs.server.protocol.FinalizeCommand;
 import org.apache.hadoop.hdfs.server.protocol.NamenodeCommand;
 import org.apache.hadoop.hdfs.server.protocol.NamenodeProtocol;
 import org.apache.hadoop.hdfs.server.protocol.NamenodeProtocols;
@@ -803,7 +804,7 @@ class NameNodeRpcServer implements NamenodeProtocols {
 
     namesystem.getBlockManager().processReport(nodeReg, poolId, blist);
     if (nn.getFSImage().isUpgradeFinalized())
-      return new DatanodeCommand.Finalize(poolId);
+      return new FinalizeCommand(poolId);
     return null;
   }
 
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/protocol/DatanodeCommand.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/protocol/DatanodeCommand.java
index 52396d2408f..9c6950f2174 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/protocol/DatanodeCommand.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/protocol/DatanodeCommand.java
@@ -17,17 +17,9 @@
  */
 package org.apache.hadoop.hdfs.server.protocol;
 
-import java.io.DataInput;
-import java.io.DataOutput;
-import java.io.IOException;
-
+import org.apache.avro.reflect.Union;
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;
-import org.apache.hadoop.io.Writable;
-import org.apache.hadoop.io.WritableFactory;
-import org.apache.hadoop.io.WritableFactories;
-import org.apache.hadoop.io.WritableUtils;
-import org.apache.avro.reflect.Union;
 
 /**
  * Base class for data-node command.
@@ -36,55 +28,13 @@ import org.apache.avro.reflect.Union;
 
 // Declare subclasses for Avro's denormalized representation
 @Union({Void.class,
-      DatanodeCommand.Register.class, DatanodeCommand.Finalize.class,
+      RegisterCommand.class, FinalizeCommand.class,
       BlockCommand.class, UpgradeCommand.class,
       BlockRecoveryCommand.class, KeyUpdateCommand.class})
 
 @InterfaceAudience.Private
 @InterfaceStability.Evolving
 public abstract class DatanodeCommand extends ServerCommand {
-  static class Register extends DatanodeCommand {
-    private Register() {super(DatanodeProtocol.DNA_REGISTER);}
-    public void readFields(DataInput in) {}
-    public void write(DataOutput out) {}
-  }
-
-  public static class Finalize extends DatanodeCommand {
-    String blockPoolId;
-    private Finalize() {
-      super(DatanodeProtocol.DNA_FINALIZE);
-    }
-    
-    public Finalize(String bpid) {
-      super(DatanodeProtocol.DNA_FINALIZE);
-      blockPoolId = bpid;
-    }
-    
-    public String getBlockPoolId() {
-      return blockPoolId;
-    }
-    
-    public void readFields(DataInput in) throws IOException {
-      blockPoolId = WritableUtils.readString(in);
-    }
-    public void write(DataOutput out) throws IOException {
-      WritableUtils.writeString(out, blockPoolId);
-    }
-  }
-
-  static {                                      // register a ctor
-    WritableFactories.setFactory(Register.class,
-        new WritableFactory() {
-          public Writable newInstance() {return new Register();}
-        });
-    WritableFactories.setFactory(Finalize.class,
-        new WritableFactory() {
-          public Writable newInstance() {return new Finalize();}
-        });
-  }
-
-  public static final DatanodeCommand REGISTER = new Register();
-  
   public DatanodeCommand() {
     super();
   }
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestDeadDatanode.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestDeadDatanode.java
index bc33f175bf1..2e73ec556a2 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestDeadDatanode.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestDeadDatanode.java
@@ -37,6 +37,7 @@ import org.apache.hadoop.hdfs.server.protocol.DatanodeCommand;
 import org.apache.hadoop.hdfs.server.protocol.DatanodeProtocol;
 import org.apache.hadoop.hdfs.server.protocol.DatanodeRegistration;
 import org.apache.hadoop.hdfs.server.protocol.ReceivedDeletedBlockInfo;
+import org.apache.hadoop.hdfs.server.protocol.RegisterCommand;
 import org.junit.After;
 import org.junit.Test;
 
@@ -129,7 +130,7 @@ public class TestDeadDatanode {
     // that asks datanode to register again
     DatanodeCommand[] cmd = dnp.sendHeartbeat(reg, 0, 0, 0, 0, 0, 0, 0);
     Assert.assertEquals(1, cmd.length);
-    Assert.assertEquals(cmd[0].getAction(), DatanodeCommand.REGISTER
+    Assert.assertEquals(cmd[0].getAction(), RegisterCommand.REGISTER
         .getAction());
   }
 }