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Subject: svn commit: r1077058 - in
 /hadoop/common/branches/branch-0.20-security-patches/src:
 hdfs/org/apache/hadoop/hdfs/server/namenode/
 test/org/apache/hadoop/hdfs/server/namenode/ webapps/hdfs/
Date: Fri, 04 Mar 2011 03:36:28 -0000
To: common-commits@hadoop.apache.org
From: omalley@apache.org
Message-Id: <20110304033628.5A05D2388901@eris.apache.org>

Author: omalley
Date: Fri Mar  4 03:36:27 2011
New Revision: 1077058

URL: http://svn.apache.org/viewvc?rev=1077058&view=rev
Log:
commit 6e41b35b96303a453078320539126493f786a3dd
Author: Jitendra Nath Pandey <jitendra@yahoo-inc.com>
Date:   Tue Nov 24 11:42:17 2009 -0800

    HDFS-758. Changes to report decommissioning status on namenode web
              UI.
    Patch URL: https://issues.apache.org/jira/secure/attachment/12426000/HDFS-758.5.0-20.patch
    
    +++ b/YAHOO-CHANGES.txt
    +    HDFS-758. Changes to report status of decommissioining on the namenode web
    +    UI. (jitendra)
    +

Added:
    hadoop/common/branches/branch-0.20-security-patches/src/test/org/apache/hadoop/hdfs/server/namenode/TestDecommissioningStatus.java
Modified:
    hadoop/common/branches/branch-0.20-security-patches/src/hdfs/org/apache/hadoop/hdfs/server/namenode/DatanodeDescriptor.java
    hadoop/common/branches/branch-0.20-security-patches/src/hdfs/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java
    hadoop/common/branches/branch-0.20-security-patches/src/webapps/hdfs/dfshealth.jsp
    hadoop/common/branches/branch-0.20-security-patches/src/webapps/hdfs/dfsnodelist.jsp

Modified: hadoop/common/branches/branch-0.20-security-patches/src/hdfs/org/apache/hadoop/hdfs/server/namenode/DatanodeDescriptor.java
URL: http://svn.apache.org/viewvc/hadoop/common/branches/branch-0.20-security-patches/src/hdfs/org/apache/hadoop/hdfs/server/namenode/DatanodeDescriptor.java?rev=1077058&r1=1077057&r2=1077058&view=diff
==============================================================================
--- hadoop/common/branches/branch-0.20-security-patches/src/hdfs/org/apache/hadoop/hdfs/server/namenode/DatanodeDescriptor.java (original)
+++ hadoop/common/branches/branch-0.20-security-patches/src/hdfs/org/apache/hadoop/hdfs/server/namenode/DatanodeDescriptor.java Fri Mar  4 03:36:27 2011
@@ -44,6 +44,11 @@ import org.apache.hadoop.io.WritableUtil
 
  **************************************************/
 public class DatanodeDescriptor extends DatanodeInfo {
+  
+  // Stores status of decommissioning.
+  // If node is not decommissioning, do not use this object for anything.
+  DecommissioningStatus decommissioningStatus = new DecommissioningStatus();
+
   /** Block and targets pair */
   public static class BlockTargetPair {
     public final Block block;
@@ -462,4 +467,53 @@ public class DatanodeDescriptor extends 
       lastBlocksScheduledRollTime = now;
     }
   }
+  
+  class DecommissioningStatus {
+    int underReplicatedBlocks;
+    int decommissionOnlyReplicas;
+    int underReplicatedInOpenFiles;
+    long startTime;
+
+    synchronized void set(int underRep, int onlyRep, int underConstruction) {
+      if (isDecommissionInProgress() == false) {
+        return;
+      }
+      underReplicatedBlocks = underRep;
+      decommissionOnlyReplicas = onlyRep;
+      underReplicatedInOpenFiles = underConstruction;
+    }
+
+    synchronized int getUnderReplicatedBlocks() {
+      if (isDecommissionInProgress() == false) {
+        return 0;
+      }
+      return underReplicatedBlocks;
+    }
+
+    synchronized int getDecommissionOnlyReplicas() {
+      if (isDecommissionInProgress() == false) {
+        return 0;
+      }
+      return decommissionOnlyReplicas;
+    }
+
+    synchronized int getUnderReplicatedInOpenFiles() {
+      if (isDecommissionInProgress() == false) {
+        return 0;
+      }
+      return underReplicatedInOpenFiles;
+    }
+
+    synchronized void setStartTime(long time) {
+      startTime = time;
+    }
+
+    synchronized long getStartTime() {
+      if (isDecommissionInProgress() == false) {
+        return 0;
+      }
+      return startTime;
+    }
+  } // End of class DecommissioningStatus
+  
 }

Modified: hadoop/common/branches/branch-0.20-security-patches/src/hdfs/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java
URL: http://svn.apache.org/viewvc/hadoop/common/branches/branch-0.20-security-patches/src/hdfs/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java?rev=1077058&r1=1077057&r2=1077058&view=diff
==============================================================================
--- hadoop/common/branches/branch-0.20-security-patches/src/hdfs/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java (original)
+++ hadoop/common/branches/branch-0.20-security-patches/src/hdfs/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java Fri Mar  4 03:36:27 2011
@@ -3626,14 +3626,11 @@ public class FSNamesystem implements FSC
     if (!node.isDecommissionInProgress() && !node.isDecommissioned()) {
       LOG.info("Start Decommissioning node " + node.getName());
       node.startDecommission();
+      node.decommissioningStatus.setStartTime(now());
       //
       // all the blocks that reside on this node have to be 
       // replicated.
-      Iterator<Block> decommissionBlocks = node.getBlockIterator();
-      while(decommissionBlocks.hasNext()) {
-        Block block = decommissionBlocks.next();
-        updateNeededReplications(block, -1, 0);
-      }
+      checkDecommissionStateInternal(node);
     }
   }
 
@@ -3748,12 +3745,40 @@ public class FSNamesystem implements FSC
     return countNodes(b, blocksMap.nodeIterator(b));
   }
 
+  private void logBlockReplicationInfo(Block block, DatanodeDescriptor srcNode,
+      NumberReplicas num) {
+    int curReplicas = num.liveReplicas();
+    int curExpectedReplicas = getReplication(block);
+    INode fileINode = blocksMap.getINode(block);
+    Iterator<DatanodeDescriptor> nodeIter = blocksMap.nodeIterator(block);
+    StringBuffer nodeList = new StringBuffer();
+    while (nodeIter.hasNext()) {
+      DatanodeDescriptor node = nodeIter.next();
+      nodeList.append(node.name);
+      nodeList.append(" ");
+    }
+    FSNamesystem.LOG.info("Block: " + block + ", Expected Replicas: "
+        + curExpectedReplicas + ", live replicas: " + curReplicas
+        + ", corrupt replicas: " + num.corruptReplicas()
+        + ", decommissioned replicas: " + num.decommissionedReplicas()
+        + ", excess replicas: " + num.excessReplicas() + ", Is Open File: "
+        + fileINode.isUnderConstruction() + ", Datanodes having this block: "
+        + nodeList + ", Current Datanode: " + srcNode.name
+        + ", Is current datanode decommissioning: "
+        + srcNode.isDecommissionInProgress());
+  }
+
+  
   /**
    * Return true if there are any blocks on this node that have not
    * yet reached their replication factor. Otherwise returns false.
    */
   private boolean isReplicationInProgress(DatanodeDescriptor srcNode) {
     boolean status = false;
+    int underReplicatedBlocks = 0;
+    int decommissionOnlyReplicas = 0;
+    int underReplicatedInOpenFiles = 0;
+
     for(final Iterator<Block> i = srcNode.getBlockIterator(); i.hasNext(); ) {
       final Block block = i.next();
       INode fileINode = blocksMap.getINode(block);
@@ -3763,7 +3788,19 @@ public class FSNamesystem implements FSC
         int curReplicas = num.liveReplicas();
         int curExpectedReplicas = getReplication(block);
         if (curExpectedReplicas > curReplicas) {
-          status = true;
+          // Log info about one block for this node which needs replication
+          if (!status) {
+            status = true;
+            logBlockReplicationInfo(block, srcNode, num);
+          }
+          underReplicatedBlocks++;
+          if ((curReplicas == 0) && (num.decommissionedReplicas() > 0)) {
+            decommissionOnlyReplicas++;
+          }
+          if (fileINode.isUnderConstruction()) {
+            underReplicatedInOpenFiles++;
+          }
+
           if (!neededReplications.contains(block) &&
             pendingReplications.getNumReplicas(block) == 0) {
             //
@@ -3779,6 +3816,9 @@ public class FSNamesystem implements FSC
         }
       }
     }
+    srcNode.decommissioningStatus.set(underReplicatedBlocks,
+        decommissionOnlyReplicas, underReplicatedInOpenFiles);
+
     return status;
   }
 
@@ -4746,4 +4786,16 @@ public class FSNamesystem implements FSC
       }
     }
   }
+  
+  public synchronized ArrayList<DatanodeDescriptor> getDecommissioningNodes() {
+    ArrayList<DatanodeDescriptor> decommissioningNodes = new ArrayList<DatanodeDescriptor>();
+    ArrayList<DatanodeDescriptor> results = getDatanodeListForReport(DatanodeReportType.LIVE);
+    for (Iterator<DatanodeDescriptor> it = results.iterator(); it.hasNext();) {
+      DatanodeDescriptor node = it.next();
+      if (node.isDecommissionInProgress()) {
+        decommissioningNodes.add(node);
+      }
+    }
+    return decommissioningNodes;
+  }
 }

Added: hadoop/common/branches/branch-0.20-security-patches/src/test/org/apache/hadoop/hdfs/server/namenode/TestDecommissioningStatus.java
URL: http://svn.apache.org/viewvc/hadoop/common/branches/branch-0.20-security-patches/src/test/org/apache/hadoop/hdfs/server/namenode/TestDecommissioningStatus.java?rev=1077058&view=auto
==============================================================================
--- hadoop/common/branches/branch-0.20-security-patches/src/test/org/apache/hadoop/hdfs/server/namenode/TestDecommissioningStatus.java (added)
+++ hadoop/common/branches/branch-0.20-security-patches/src/test/org/apache/hadoop/hdfs/server/namenode/TestDecommissioningStatus.java Fri Mar  4 03:36:27 2011
@@ -0,0 +1,228 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hdfs.server.namenode;
+
+import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.Random;
+
+import org.junit.BeforeClass;
+import org.junit.AfterClass;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FSDataOutputStream;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hdfs.DFSClient;
+import org.apache.hadoop.hdfs.MiniDFSCluster;
+import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
+import org.apache.hadoop.hdfs.protocol.FSConstants.DatanodeReportType;
+import org.apache.hadoop.hdfs.server.namenode.FSNamesystem;
+import org.apache.hadoop.hdfs.server.namenode.DatanodeDescriptor;
+
+/**
+ * This class tests the decommissioning of nodes.
+ */
+public class TestDecommissioningStatus {
+  private static final long seed = 0xDEADBEEFL;
+  private static final int blockSize = 8192;
+  private static final int fileSize = 16384;
+  private static final int numDatanodes = 2;
+  private static MiniDFSCluster cluster;
+  private static FileSystem fileSys;
+  private static Path excludeFile;
+  private static FileSystem localFileSys;
+  private static Configuration conf;
+  private static Path dir;
+
+  ArrayList<String> decommissionedNodes = new ArrayList<String>(numDatanodes);
+  
+  @BeforeClass
+  public static void setUp() throws Exception {
+    conf = new Configuration();
+    conf.setBoolean("dfs.replication.considerLoad", false);
+
+    // Set up the hosts/exclude files.
+    localFileSys = FileSystem.getLocal(conf);
+    Path workingDir = localFileSys.getWorkingDirectory();
+    dir = new Path(workingDir, "build/test/data/work-dir/decommission");
+    assertTrue(localFileSys.mkdirs(dir));
+    excludeFile = new Path(dir, "exclude");
+    conf.set("dfs.hosts.exclude", excludeFile.toUri().getPath());
+    conf.setInt("heartbeat.recheck.interval", 2000);
+    conf.setInt("dfs.heartbeat.interval", 1);
+    conf.setInt("dfs.replication.pending.timeout.sec", 4);
+    conf.setInt("dfs.replication.interval", 1000);
+    conf.setInt("dfs.namenode.decommission.interval", 1);
+    writeConfigFile(localFileSys, excludeFile, null);
+
+    cluster = new MiniDFSCluster(conf, numDatanodes, true, null);
+    cluster.waitActive();
+    fileSys = cluster.getFileSystem();
+  }
+
+  @AfterClass
+  public static void tearDown() throws Exception {
+    if(fileSys != null) fileSys.close();
+    if(cluster != null) cluster.shutdown();
+  }
+
+  private static void writeConfigFile(FileSystem fs, Path name,
+      ArrayList<String> nodes) throws IOException {
+
+    // delete if it already exists
+    if (fs.exists(name)) {
+      fs.delete(name, true);
+    }
+
+    FSDataOutputStream stm = fs.create(name);
+
+    if (nodes != null) {
+      for (Iterator<String> it = nodes.iterator(); it.hasNext();) {
+        String node = it.next();
+        stm.writeBytes(node);
+        stm.writeBytes("\n");
+      }
+    }
+    stm.close();
+  }
+
+  private void writeFile(FileSystem fileSys, Path name, short repl)
+      throws IOException {
+    // create and write a file that contains three blocks of data
+    FSDataOutputStream stm = fileSys.create(name, true, fileSys.getConf()
+        .getInt("io.file.buffer.size", 4096), repl, (long) blockSize);
+    byte[] buffer = new byte[fileSize];
+    Random rand = new Random(seed);
+    rand.nextBytes(buffer);
+    stm.write(buffer);
+    stm.close();
+  }
+ 
+  private FSDataOutputStream writeIncompleteFile(FileSystem fileSys, Path name,
+      short repl) throws IOException {
+    // create and write a file that contains three blocks of data
+    FSDataOutputStream stm = fileSys.create(name, true, fileSys.getConf()
+        .getInt("io.file.buffer.size", 4096), repl, (long) blockSize);
+    byte[] buffer = new byte[fileSize];
+    Random rand = new Random(seed);
+    rand.nextBytes(buffer);
+    stm.write(buffer);
+    // Do not close stream, return it
+    // so that it is not garbage collected
+    return stm;
+  }
+  
+  private void cleanupFile(FileSystem fileSys, Path name) throws IOException {
+    assertTrue(fileSys.exists(name));
+    fileSys.delete(name, true);
+    assertTrue(!fileSys.exists(name));
+  }
+
+  /*
+   * Decommissions the node at the given index
+   */
+  private String decommissionNode(FSNamesystem namesystem, Configuration conf,
+      DFSClient client, FileSystem localFileSys, int nodeIndex)
+      throws IOException {
+    DatanodeInfo[] info = client.datanodeReport(DatanodeReportType.LIVE);
+
+    String nodename = info[nodeIndex].getName();
+    System.out.println("Decommissioning node: " + nodename);
+
+    // write nodename into the exclude file.
+    ArrayList<String> nodes = new ArrayList<String>(decommissionedNodes);
+    nodes.add(nodename);
+    writeConfigFile(localFileSys, excludeFile, nodes);
+    namesystem.refreshNodes(conf);
+    return nodename;
+  }
+
+  private void checkDecommissionStatus(DatanodeDescriptor decommNode,
+      int expectedUnderRep, int expectedDecommissionOnly,
+      int expectedUnderRepInOpenFiles) {
+    assertEquals(decommNode.decommissioningStatus.getUnderReplicatedBlocks(),
+        expectedUnderRep);
+    assertEquals(
+        decommNode.decommissioningStatus.getDecommissionOnlyReplicas(),
+        expectedDecommissionOnly);
+    assertEquals(decommNode.decommissioningStatus
+        .getUnderReplicatedInOpenFiles(), expectedUnderRepInOpenFiles);
+  }
+  
+  /**
+   * Tests Decommissioning Status in DFS.
+   */
+
+  @Test
+  public void testDecommissionStatus() throws IOException, InterruptedException {
+    InetSocketAddress addr = new InetSocketAddress("localhost", cluster
+        .getNameNodePort());
+    DFSClient client = new DFSClient(addr, conf);
+    DatanodeInfo[] info = client.datanodeReport(DatanodeReportType.LIVE);
+    assertEquals("Number of Datanodes ", 2, info.length);
+    FileSystem fileSys = cluster.getFileSystem();
+
+    short replicas = 2;
+    //
+    // Decommission one node. Verify the decommission status
+    // 
+    Path file1 = new Path("decommission.dat");
+    writeFile(fileSys, file1, replicas);
+
+    Path file2 = new Path("decommission1.dat");
+    FSDataOutputStream st1 = writeIncompleteFile(fileSys, file2, replicas);
+    Thread.sleep(5000);
+
+    FSNamesystem fsn = cluster.getNameNode().getNamesystem();
+    for (int iteration = 0; iteration < numDatanodes; iteration++) {
+      String downnode = decommissionNode(fsn, conf, client, localFileSys,
+          iteration);
+      decommissionedNodes.add(downnode);
+      Thread.sleep(5000);
+      ArrayList<DatanodeDescriptor> decommissioningNodes = fsn
+          .getDecommissioningNodes();
+      if (iteration == 0) {
+        assertEquals(decommissioningNodes.size(), 1);
+        DatanodeDescriptor decommNode = decommissioningNodes.get(0);
+        checkDecommissionStatus(decommNode, 4, 0, 2);
+      } else {
+        assertEquals(decommissioningNodes.size(), 2);
+        DatanodeDescriptor decommNode1 = decommissioningNodes.get(0);
+        DatanodeDescriptor decommNode2 = decommissioningNodes.get(1);
+        checkDecommissionStatus(decommNode1, 4, 4, 2);
+        checkDecommissionStatus(decommNode2, 4, 4, 2);
+      }
+    }
+    // Call refreshNodes on FSNamesystem with empty exclude file.
+    // This will remove the datanodes from decommissioning list and
+    // make them available again.
+    writeConfigFile(localFileSys, excludeFile, null);
+    fsn.refreshNodes(conf);
+    st1.close();
+    cleanupFile(fileSys, file1);
+    cleanupFile(fileSys, file2);
+    cleanupFile(localFileSys, dir);
+  }
+}

Modified: hadoop/common/branches/branch-0.20-security-patches/src/webapps/hdfs/dfshealth.jsp
URL: http://svn.apache.org/viewvc/hadoop/common/branches/branch-0.20-security-patches/src/webapps/hdfs/dfshealth.jsp?rev=1077058&r1=1077057&r2=1077058&view=diff
==============================================================================
--- hadoop/common/branches/branch-0.20-security-patches/src/webapps/hdfs/dfshealth.jsp (original)
+++ hadoop/common/branches/branch-0.20-security-patches/src/webapps/hdfs/dfshealth.jsp Fri Mar  4 03:36:27 2011
@@ -163,6 +163,9 @@
     ArrayList<DatanodeDescriptor> dead = new ArrayList<DatanodeDescriptor>();
     jspHelper.DFSNodesStatus(live, dead);
 
+    ArrayList<DatanodeDescriptor> decommissioning = fsn
+        .getDecommissioningNodes();
+	
     sorterField = request.getParameter("sorter/field");
     sorterOrder = request.getParameter("sorter/order");
     if ( sorterField == null )
@@ -214,8 +217,14 @@
 	       		colTxt() + ":" + colTxt() + live.size() +
 	       rowTxt() + colTxt() +
 	       		"<a href=\"dfsnodelist.jsp?whatNodes=DEAD\">Dead Nodes</a> " +
-	       		colTxt() + ":" + colTxt() + dead.size() +
-               "</table></div><br>\n" );
+	       		colTxt() + ":" + colTxt() + dead.size() + rowTxt() + colTxt()
+				+ "<a href=\"dfsnodelist.jsp?whatNodes=DECOMMISSIONING\">"
+				+ "Decommissioning Nodes</a> "
+				+ colTxt() + ":" + colTxt() + decommissioning.size()
+				+ rowTxt() + colTxt()
+				+ "Number of Under-Replicated Blocks" + colTxt() + ":" + colTxt()
+				+ fsn.getUnderReplicatedBlocks()
+                + "</table></div><br>\n" );
     
     if (live.isEmpty() && dead.isEmpty()) {
         out.print("There are no datanodes in the cluster");

Modified: hadoop/common/branches/branch-0.20-security-patches/src/webapps/hdfs/dfsnodelist.jsp
URL: http://svn.apache.org/viewvc/hadoop/common/branches/branch-0.20-security-patches/src/webapps/hdfs/dfsnodelist.jsp?rev=1077058&r1=1077057&r2=1077058&view=diff
==============================================================================
--- hadoop/common/branches/branch-0.20-security-patches/src/webapps/hdfs/dfsnodelist.jsp (original)
+++ hadoop/common/branches/branch-0.20-security-patches/src/webapps/hdfs/dfsnodelist.jsp Fri Mar  4 03:36:27 2011
@@ -49,6 +49,45 @@ String NodeHeaderStr(String name) {
 	return ret;
 }
 
+void generateDecommissioningNodeData(JspWriter out, DatanodeDescriptor d,
+      String suffix, boolean alive, int nnHttpPort) throws IOException {
+    String url = "http://" + d.getHostName() + ":" + d.getInfoPort()
+      + "/browseDirectory.jsp?namenodeInfoPort=" + nnHttpPort + "&dir="
+      + URLEncoder.encode("/", "UTF-8");
+
+    String name = d.getHostName() + ":" + d.getPort();
+    if (!name.matches("\\d+\\.\\d+.\\d+\\.\\d+.*"))
+      name = name.replaceAll("\\.[^.:]*", "");
+    int idx = (suffix != null && name.endsWith(suffix)) ? name
+        .indexOf(suffix) : -1;
+
+    out.print(rowTxt() + "<td class=\"name\"><a title=\"" + d.getHost() + ":"
+        + d.getPort() + "\" href=\"" + url + "\">"
+        + ((idx > 0) ? name.substring(0, idx) : name) + "</a>"
+        + ((alive) ? "" : "\n"));
+      if (!alive) {
+        return;
+      }
+
+    long decommRequestTime = d.decommissioningStatus.getStartTime();
+    long timestamp = d.getLastUpdate();
+    long currentTime = System.currentTimeMillis();
+    long hoursSinceDecommStarted = (currentTime - decommRequestTime)/3600000;
+    long remainderMinutes = ((currentTime - decommRequestTime)/60000) % 60;
+    out.print("<td class=\"lastcontact\"> "
+        + ((currentTime - timestamp) / 1000)
+        + "<td class=\"underreplicatedblocks\">"
+        + d.decommissioningStatus.getUnderReplicatedBlocks()
+        + "<td class=\"blockswithonlydecommissioningreplicas\">"
+        + d.decommissioningStatus.getDecommissionOnlyReplicas()
+        + "<td class=\"underrepblocksinfilesunderconstruction\">"
+        + d.decommissioningStatus.getUnderReplicatedInOpenFiles()
+        + "<td class=\"timesincedecommissionrequest\">"
+        + hoursSinceDecommStarted + " hrs " + remainderMinutes + " mins"
+        + "\n");
+}
+
+
 public void generateNodeData( JspWriter out, DatanodeDescriptor d,
 		String suffix, boolean alive,
 		int nnHttpPort )
@@ -209,7 +248,7 @@ throws IOException {
 				}
 			}
 			out.print("</table>\n");
-		} else {
+		} else if (whatNodes.equals("DEAD")) {
 
 			out.print("<br> <a name=\"DeadNodes\" id=\"title\"> " +
 					" Dead Datanodes : " +dead.size() + "</a><br><br>\n");
@@ -225,8 +264,36 @@ throws IOException {
 
 				out.print("</table>\n");
 			}
-		}
-		out.print("</div>");
+		} else if (whatNodes.equals("DECOMMISSIONING")) {
+			// Decommissioning Nodes
+			ArrayList<DatanodeDescriptor> decommissioning = nn.getNamesystem()
+			    .getDecommissioningNodes();
+			out.print("<br> <a name=\"DecommissioningNodes\" id=\"title\"> "
+			    + " Decommissioning Datanodes : " + decommissioning.size()
+                            + "</a><br><br>\n");
+	                if (decommissioning.size() > 0) {
+                          out.print("<table border=1 cellspacing=0> <tr class=\"headRow\"> "
+                              + "<th " + NodeHeaderStr("name")
+                              + "> Node <th " + NodeHeaderStr("lastcontact")
+                              + "> Last <br>Contact <th "
+                              + NodeHeaderStr("underreplicatedblocks")
+                              + "> Under Replicated Blocks <th "
+                              + NodeHeaderStr("blockswithonlydecommissioningreplicas")
+		              + "> Blocks With No <br> Live Replicas <th "
+	                      + NodeHeaderStr("underrepblocksinfilesunderconstruction") 
+	                      + "> Under Replicated Blocks <br> In Files Under Construction"
+	                      + " <th " + NodeHeaderStr("timesincedecommissionrequest")
+	                      + "> Time Since Decommissioning Started"
+                          );
+                          jspHelper.sortNodeList(decommissioning, "name", "ASC");
+                          for (int i = 0; i < decommissioning.size(); i++) {
+                            generateDecommissioningNodeData(out, decommissioning.get(i),
+                                port_suffix, true, nnHttpPort);
+                          }
+                          out.print("</table>\n");
+                        }
+                        out.print("</div>");
+                  }
 	}
 }%>