HDFS-3934. duplicative dfs_hosts entries handled wrong (all files) (cmccabe)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1493234 13f79535-47bb-0310-9956-ffa450edef68

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/HostsFileReader.java

@@ -48,7 +48,8 @@ public class HostsFileReader {
     refresh();
   }
 
-  private void readFileToSet(String filename, Set<String> set) throws IOException {
+  public static void readFileToSet(String type,
+      String filename, Set<String> set) throws IOException {
     File file = new File(filename);
     FileInputStream fis = new FileInputStream(file);
     BufferedReader reader = null;
@@ -63,9 +64,10 @@ public class HostsFileReader {
               // Everything from now on is a comment
               break;
             }
-            if (!nodes[i].equals("")) {
-              LOG.info("Adding " + nodes[i] + " to the list of hosts from " + filename);
-              set.add(nodes[i]);  // might need to add canonical name
+            if (!nodes[i].isEmpty()) {
+              LOG.info("Adding " + nodes[i] + " to the list of " + type +
+                  " hosts from " + filename);
+              set.add(nodes[i]);
             }
           }
         }
@@ -82,13 +84,13 @@ public class HostsFileReader {
     LOG.info("Refreshing hosts (include/exclude) list");
     if (!includesFile.equals("")) {
       Set<String> newIncludes = new HashSet<String>();
-      readFileToSet(includesFile, newIncludes);
+      readFileToSet("included", includesFile, newIncludes);
       // switch the new hosts that are to be included
       includes = newIncludes;
     }
     if (!excludesFile.equals("")) {
       Set<String> newExcludes = new HashSet<String>();
-      readFileToSet(excludesFile, newExcludes);
+      readFileToSet("excluded", excludesFile, newExcludes);
       // switch the excluded hosts
       excludes = newExcludes;
     }

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

@@ -175,6 +175,9 @@ Release 2.1.0-beta - UNRELEASED
   OPTIMIZATIONS
 
   BUG FIXES
+
+    HDFS-3934. duplicative dfs_hosts entries handled wrong. (Colin Patrick
+    McCabe)
     
     HDFS-4470. Several HDFS tests attempt file operations on invalid HDFS
     paths when running on Windows. (Chris Nauroth via suresh)

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

@@ -327,7 +327,7 @@ public class DFSConfigKeys extends CommonConfigurationKeys {
   public static final String  DFS_DATANODE_HTTPS_ADDRESS_DEFAULT = "0.0.0.0:" + DFS_DATANODE_HTTPS_DEFAULT_PORT;
   public static final String  DFS_DATANODE_IPC_ADDRESS_KEY = "dfs.datanode.ipc.address";
   public static final int     DFS_DATANODE_IPC_DEFAULT_PORT = 50020;
-  public static final String  DFS_DATANODE_IPC_ADDRESS_DEFAULT = "0.0.0.0" + DFS_DATANODE_IPC_DEFAULT_PORT;
+  public static final String  DFS_DATANODE_IPC_ADDRESS_DEFAULT = "0.0.0.0:" + DFS_DATANODE_IPC_DEFAULT_PORT;
   public static final String  DFS_DATANODE_MIN_SUPPORTED_NAMENODE_VERSION_KEY = "dfs.datanode.min.supported.namenode.version";
   public static final String  DFS_DATANODE_MIN_SUPPORTED_NAMENODE_VERSION_DEFAULT = "2.0.0-SNAPSHOT";
 

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/DatanodeManager.java

@@ -26,11 +26,9 @@ import java.net.UnknownHostException;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Comparator;
-import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
 import java.util.NavigableMap;
-import java.util.Set;
 import java.util.TreeMap;
 
 import org.apache.commons.logging.Log;
@@ -50,6 +48,17 @@ import org.apache.hadoop.hdfs.protocol.HdfsConstants.DatanodeReportType;
 import org.apache.hadoop.hdfs.protocol.LocatedBlock;
 import org.apache.hadoop.hdfs.protocol.UnregisteredNodeException;
 import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeDescriptor.BlockTargetPair;
+import org.apache.hadoop.hdfs.server.namenode.HostFileManager;
+import org.apache.hadoop.hdfs.server.namenode.HostFileManager.Entry;
+import org.apache.hadoop.hdfs.server.namenode.HostFileManager.EntrySet;
+import org.apache.hadoop.hdfs.server.namenode.HostFileManager.MutableEntrySet;
+import org.apache.hadoop.hdfs.server.namenode.NameNode;
+import org.apache.hadoop.hdfs.server.namenode.Namesystem;
+import org.apache.hadoop.hdfs.server.protocol.BalancerBandwidthCommand;
+import org.apache.hadoop.hdfs.server.namenode.HostFileManager;
+import org.apache.hadoop.hdfs.server.namenode.HostFileManager.Entry;
+import org.apache.hadoop.hdfs.server.namenode.HostFileManager.EntrySet;
+import org.apache.hadoop.hdfs.server.namenode.HostFileManager.MutableEntrySet;
 import org.apache.hadoop.hdfs.server.namenode.NameNode;
 import org.apache.hadoop.hdfs.server.namenode.Namesystem;
 import org.apache.hadoop.hdfs.server.protocol.BalancerBandwidthCommand;
@@ -62,16 +71,17 @@ 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.io.IOUtils;
 import org.apache.hadoop.ipc.Server;
 import org.apache.hadoop.net.CachedDNSToSwitchMapping;
 import org.apache.hadoop.net.DNSToSwitchMapping;
+import org.apache.hadoop.net.NetUtils;
 import org.apache.hadoop.net.NetworkTopology;
 import org.apache.hadoop.net.NetworkTopology.InvalidTopologyException;
 import org.apache.hadoop.net.Node;
 import org.apache.hadoop.net.NodeBase;
 import org.apache.hadoop.net.ScriptBasedMapping;
 import org.apache.hadoop.util.Daemon;
-import org.apache.hadoop.util.HostsFileReader;
 import org.apache.hadoop.util.ReflectionUtils;
 import org.apache.hadoop.util.Time;
 
@@ -120,8 +130,14 @@ public class DatanodeManager {
 
   private final DNSToSwitchMapping dnsToSwitchMapping;
 
+  private final int defaultXferPort;
+  
+  private final int defaultInfoPort;
+
+  private final int defaultIpcPort;
+
   /** Read include/exclude files*/
-  private final HostsFileReader hostsReader;
+  private final HostFileManager hostFileManager = new HostFileManager();
 
   /** The period to wait for datanode heartbeat.*/
   private final long heartbeatExpireInterval;
@@ -162,13 +178,25 @@ public class DatanodeManager {
     this.namesystem = namesystem;
     this.blockManager = blockManager;
     
-    networktopology = NetworkTopology.getInstance(conf);
-
     this.heartbeatManager = new HeartbeatManager(namesystem, blockManager, conf);
 
-    this.hostsReader = new HostsFileReader(
-        conf.get(DFSConfigKeys.DFS_HOSTS, ""),
+    networktopology = NetworkTopology.getInstance(conf);
+
+    this.defaultXferPort = NetUtils.createSocketAddr(
+          conf.get(DFSConfigKeys.DFS_DATANODE_ADDRESS_KEY,
+              DFSConfigKeys.DFS_DATANODE_ADDRESS_DEFAULT)).getPort();
+    this.defaultInfoPort = NetUtils.createSocketAddr(
+          conf.get(DFSConfigKeys.DFS_DATANODE_HTTP_ADDRESS_KEY,
+              DFSConfigKeys.DFS_DATANODE_HTTPS_ADDRESS_DEFAULT)).getPort();
+    this.defaultIpcPort = NetUtils.createSocketAddr(
+          conf.get(DFSConfigKeys.DFS_DATANODE_IPC_ADDRESS_KEY,
+              DFSConfigKeys.DFS_DATANODE_IPC_ADDRESS_DEFAULT)).getPort();
+    try {
+      this.hostFileManager.refresh(conf.get(DFSConfigKeys.DFS_HOSTS, ""),
         conf.get(DFSConfigKeys.DFS_HOSTS_EXCLUDE, ""));
+    } catch (IOException e) {
+      LOG.error("error reading hosts files: ", e);
+    }
 
     this.dnsToSwitchMapping = ReflectionUtils.newInstance(
         conf.getClass(DFSConfigKeys.NET_TOPOLOGY_NODE_SWITCH_MAPPING_IMPL_KEY, 
@@ -178,9 +206,15 @@ public class DatanodeManager {
     // locations of those hosts in the include list and store the mapping
     // in the cache; so future calls to resolve will be fast.
     if (dnsToSwitchMapping instanceof CachedDNSToSwitchMapping) {
-      dnsToSwitchMapping.resolve(new ArrayList<String>(hostsReader.getHosts()));
-    }
-    
+      final ArrayList<String> locations = new ArrayList<String>();
+      for (Entry entry : hostFileManager.getIncludes()) {
+        if (!entry.getIpAddress().isEmpty()) {
+          locations.add(entry.getIpAddress());
+        }
+      }
+      dnsToSwitchMapping.resolve(locations);
+    };
+
     final long heartbeatIntervalSeconds = conf.getLong(
         DFSConfigKeys.DFS_HEARTBEAT_INTERVAL_KEY,
         DFSConfigKeys.DFS_HEARTBEAT_INTERVAL_DEFAULT);
@@ -533,14 +567,6 @@ public class DatanodeManager {
     return networkLocation;
   }
 
-  private boolean inHostsList(DatanodeID node) {
-     return checkInList(node, hostsReader.getHosts(), false);
-  }
-  
-  private boolean inExcludedHostsList(DatanodeID node) {
-    return checkInList(node, hostsReader.getExcludedHosts(), true);
-  }
-
   /**
    * Remove an already decommissioned data node who is neither in include nor
    * exclude hosts lists from the the list of live or dead nodes.  This is used
@@ -570,51 +596,27 @@ public class DatanodeManager {
   private void removeDecomNodeFromList(final List<DatanodeDescriptor> nodeList) {
     // If the include list is empty, any nodes are welcomed and it does not
     // make sense to exclude any nodes from the cluster. Therefore, no remove.
-    if (hostsReader.getHosts().isEmpty()) {
+    if (!hostFileManager.hasIncludes()) {
       return;
     }
-    
+
     for (Iterator<DatanodeDescriptor> it = nodeList.iterator(); it.hasNext();) {
       DatanodeDescriptor node = it.next();
-      if ((!inHostsList(node)) && (!inExcludedHostsList(node))
+      if ((!hostFileManager.isIncluded(node)) && (!hostFileManager.isExcluded(node))
           && node.isDecommissioned()) {
         // Include list is not empty, an existing datanode does not appear
         // in both include or exclude lists and it has been decommissioned.
-        // Remove it from the node list.
         it.remove();
       }
     }
   }
 
-  /**
-   * Check if the given DatanodeID is in the given (include or exclude) list.
-   * 
-   * @param node the DatanodeID to check
-   * @param hostsList the list of hosts in the include/exclude file
-   * @param isExcludeList true if this is the exclude list
-   * @return true if the node is in the list, false otherwise
-   */
-  private static boolean checkInList(final DatanodeID node,
-      final Set<String> hostsList,
-      final boolean isExcludeList) {
-    // if include list is empty, host is in include list
-    if ( (!isExcludeList) && (hostsList.isEmpty()) ){
-      return true;
-    }
-    for (String name : getNodeNamesForHostFiltering(node)) {
-      if (hostsList.contains(name)) {
-        return true;
-      }
-    }
-    return false;
-  }
-
   /**
    * Decommission the node if it is in exclude list.
    */
   private void checkDecommissioning(DatanodeDescriptor nodeReg) { 
     // If the registered node is in exclude list, then decommission it
-    if (inExcludedHostsList(nodeReg)) {
+    if (hostFileManager.isExcluded(nodeReg)) {
       startDecommission(nodeReg);
     }
   }
@@ -710,7 +712,7 @@ public class DatanodeManager {
   
       // Checks if the node is not on the hosts list.  If it is not, then
       // it will be disallowed from registering. 
-      if (!inHostsList(nodeReg)) {
+      if (!hostFileManager.isIncluded(nodeReg)) {
         throw new DisallowedDatanodeException(nodeReg);
       }
         
@@ -844,9 +846,8 @@ public class DatanodeManager {
     if (conf == null) {
       conf = new HdfsConfiguration();
     }
-    hostsReader.updateFileNames(conf.get(DFSConfigKeys.DFS_HOSTS, ""), 
-                                conf.get(DFSConfigKeys.DFS_HOSTS_EXCLUDE, ""));
-    hostsReader.refresh();
+    this.hostFileManager.refresh(conf.get(DFSConfigKeys.DFS_HOSTS, ""),
+      conf.get(DFSConfigKeys.DFS_HOSTS_EXCLUDE, ""));
   }
   
   /**
@@ -858,10 +859,10 @@ public class DatanodeManager {
   private void refreshDatanodes() {
     for(DatanodeDescriptor node : datanodeMap.values()) {
       // Check if not include.
-      if (!inHostsList(node)) {
+      if (!hostFileManager.isIncluded(node)) {
         node.setDisallowed(true); // case 2.
       } else {
-        if (inExcludedHostsList(node)) {
+        if (hostFileManager.isExcluded(node)) {
           startDecommission(node); // case 3.
         } else {
           stopDecommission(node); // case 4.
@@ -1076,25 +1077,10 @@ public class DatanodeManager {
     boolean listDeadNodes = type == DatanodeReportType.ALL ||
                             type == DatanodeReportType.DEAD;
 
-    HashMap<String, String> mustList = new HashMap<String, String>();
-
-    if (listDeadNodes) {
-      // Put all nodes referenced in the hosts files in the map
-      Iterator<String> it = hostsReader.getHosts().iterator();
-      while (it.hasNext()) {
-        mustList.put(it.next(), "");
-      }
-      it = hostsReader.getExcludedHosts().iterator(); 
-      while (it.hasNext()) {
-        mustList.put(it.next(), "");
-      }
-    }
-
     ArrayList<DatanodeDescriptor> nodes = null;
-    
+    final MutableEntrySet foundNodes = new MutableEntrySet();
     synchronized(datanodeMap) {
-      nodes = new ArrayList<DatanodeDescriptor>(datanodeMap.size() + 
-                                                mustList.size());
+      nodes = new ArrayList<DatanodeDescriptor>(datanodeMap.size());
       Iterator<DatanodeDescriptor> it = datanodeMap.values().iterator();
       while (it.hasNext()) { 
         DatanodeDescriptor dn = it.next();
@@ -1102,47 +1088,45 @@ public class DatanodeManager {
         if ( (isDead && listDeadNodes) || (!isDead && listLiveNodes) ) {
           nodes.add(dn);
         }
-        for (String name : getNodeNamesForHostFiltering(dn)) {
-          mustList.remove(name);
-        }
+        foundNodes.add(dn);
       }
     }
-    
+
     if (listDeadNodes) {
-      Iterator<String> it = mustList.keySet().iterator();
-      while (it.hasNext()) {
-        // The remaining nodes are ones that are referenced by the hosts
-        // files but that we do not know about, ie that we have never
-        // head from. Eg. a host that is no longer part of the cluster
-        // or a bogus entry was given in the hosts files
-        DatanodeID dnId = parseDNFromHostsEntry(it.next());
-        DatanodeDescriptor dn = new DatanodeDescriptor(dnId); 
-        dn.setLastUpdate(0); // Consider this node dead for reporting
-        nodes.add(dn);
+      final EntrySet includedNodes = hostFileManager.getIncludes();
+      final EntrySet excludedNodes = hostFileManager.getExcludes();
+      for (Entry entry : includedNodes) {
+        if ((foundNodes.find(entry) == null) &&
+            (excludedNodes.find(entry) == null)) {
+          // The remaining nodes are ones that are referenced by the hosts
+          // files but that we do not know about, ie that we have never
+          // head from. Eg. an entry that is no longer part of the cluster
+          // or a bogus entry was given in the hosts files
+          //
+          // If the host file entry specified the xferPort, we use that.
+          // Otherwise, we guess that it is the default xfer port.
+          // We can't ask the DataNode what it had configured, because it's
+          // dead.
+          DatanodeDescriptor dn =
+              new DatanodeDescriptor(new DatanodeID(entry.getIpAddress(),
+                  entry.getPrefix(), "",
+                  entry.getPort() == 0 ? defaultXferPort : entry.getPort(),
+                  defaultInfoPort, defaultIpcPort));
+          dn.setLastUpdate(0); // Consider this node dead for reporting
+          nodes.add(dn);
+        }
       }
     }
+    if (LOG.isDebugEnabled()) {
+      LOG.debug("getDatanodeListForReport with " +
+          "includedNodes = " + hostFileManager.getIncludes() +
+          ", excludedNodes = " + hostFileManager.getExcludes() +
+          ", foundNodes = " + foundNodes +
+          ", nodes = " + nodes);
+    }
     return nodes;
   }
   
-  private static List<String> getNodeNamesForHostFiltering(DatanodeID node) {
-    String ip = node.getIpAddr();
-    String regHostName = node.getHostName();
-    int xferPort = node.getXferPort();
-    
-    List<String> names = new ArrayList<String>(); 
-    names.add(ip);
-    names.add(ip + ":" + xferPort);
-    names.add(regHostName);
-    names.add(regHostName + ":" + xferPort);
-
-    String peerHostName = node.getPeerHostName();
-    if (peerHostName != null) {
-      names.add(peerHostName);
-      names.add(peerHostName + ":" + xferPort);
-    }
-    return names;
-  }
-
   /**
    * Checks if name resolution was successful for the given address.  If IP
    * address and host name are the same, then it means name resolution has

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNode.java

@@ -936,7 +936,8 @@ public class DataNode extends Configured
     MBeans.register("DataNode", "DataNodeInfo", this);
   }
   
-  int getXferPort() {
+  @VisibleForTesting
+  public int getXferPort() {
     return streamingAddr.getPort();
   }
   

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDatanodeRegistration.java

@@ -223,6 +223,7 @@ public class TestDatanodeRegistration {
       
       DatanodeRegistration mockDnReg = mock(DatanodeRegistration.class);
       doReturn(HdfsConstants.LAYOUT_VERSION).when(mockDnReg).getVersion();
+      doReturn(123).when(mockDnReg).getXferPort();
       doReturn("fake-storage-id").when(mockDnReg).getStorageID();
       doReturn(mockStorageInfo).when(mockDnReg).getStorageInfo();
       
@@ -270,12 +271,14 @@ public class TestDatanodeRegistration {
       
       DatanodeRegistration mockDnReg = mock(DatanodeRegistration.class);
       doReturn(HdfsConstants.LAYOUT_VERSION).when(mockDnReg).getVersion();
+      doReturn(123).when(mockDnReg).getXferPort();
       doReturn("fake-storage-id").when(mockDnReg).getStorageID();
       doReturn(mockStorageInfo).when(mockDnReg).getStorageInfo();
       
       // Should succeed when software versions are the same and CTimes are the
       // same.
       doReturn(VersionInfo.getVersion()).when(mockDnReg).getSoftwareVersion();
+      doReturn(123).when(mockDnReg).getXferPort();
       rpcServer.registerDatanode(mockDnReg);
       
       // Should succeed when software versions are the same and CTimes are

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDecommission.java

@@ -24,7 +24,9 @@ import static org.junit.Assert.assertTrue;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.HashMap;
 import java.util.Iterator;
+import java.util.Map;
 import java.util.Random;
 
 import org.apache.commons.logging.Log;
@@ -41,9 +43,11 @@ import org.apache.hadoop.hdfs.protocol.DatanodeInfo.AdminStates;
 import org.apache.hadoop.hdfs.protocol.HdfsConstants.DatanodeReportType;
 import org.apache.hadoop.hdfs.protocol.LocatedBlock;
 import org.apache.hadoop.hdfs.server.namenode.FSNamesystem;
+import org.apache.hadoop.hdfs.server.namenode.HostFileManager;
 import org.apache.hadoop.hdfs.server.namenode.NameNode;
 import org.apache.hadoop.hdfs.server.namenode.NameNodeAdapter;
 import org.junit.After;
+import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
 
@@ -327,7 +331,7 @@ public class TestDecommission {
   /**
    * Tests decommission for non federated cluster
    */
-  @Test
+  @Test(timeout=360000)
   public void testDecommission() throws IOException {
     testDecommission(1, 6);
   }
@@ -335,7 +339,7 @@ public class TestDecommission {
   /**
    * Tests recommission for non federated cluster
    */
-  @Test
+  @Test(timeout=360000)
   public void testRecommission() throws IOException {
     testRecommission(1, 6);
   }
@@ -343,7 +347,7 @@ public class TestDecommission {
   /**
    * Test decommission for federeated cluster
    */
-  @Test
+  @Test(timeout=360000)
   public void testDecommissionFederation() throws IOException {
     testDecommission(2, 2);
   }
@@ -445,7 +449,7 @@ public class TestDecommission {
    * Tests cluster storage statistics during decommissioning for non
    * federated cluster
    */
-  @Test
+  @Test(timeout=360000)
   public void testClusterStats() throws Exception {
     testClusterStats(1);
   }
@@ -454,7 +458,7 @@ public class TestDecommission {
    * Tests cluster storage statistics during decommissioning for
    * federated cluster
    */
-  @Test
+  @Test(timeout=360000)
   public void testClusterStatsFederation() throws Exception {
     testClusterStats(3);
   }
@@ -491,7 +495,7 @@ public class TestDecommission {
    * in the include file are allowed to connect to the namenode in a non
    * federated cluster.
    */
-  @Test
+  @Test(timeout=360000)
   public void testHostsFile() throws IOException, InterruptedException {
     // Test for a single namenode cluster
     testHostsFile(1);
@@ -502,7 +506,7 @@ public class TestDecommission {
    * in the include file are allowed to connect to the namenode in a 
    * federated cluster.
    */
-  @Test
+  @Test(timeout=360000)
   public void testHostsFileFederation() throws IOException, InterruptedException {
     // Test for 3 namenode federated cluster
     testHostsFile(3);
@@ -519,8 +523,8 @@ public class TestDecommission {
     // Now empty hosts file and ensure the datanode is disallowed
     // from talking to namenode, resulting in it's shutdown.
     ArrayList<String>list = new ArrayList<String>();
-    final String badHostname = "BOGUSHOST";
-    list.add(badHostname);
+    final String bogusIp = "127.0.30.1";
+    list.add(bogusIp);
     writeConfigFile(hostsFile, list);
     
     for (int j = 0; j < numNameNodes; j++) {
@@ -544,7 +548,150 @@ public class TestDecommission {
       assertEquals("There should be 2 dead nodes", 2, info.length);
       DatanodeID id = cluster.getDataNodes().get(0).getDatanodeId();
       assertEquals(id.getHostName(), info[0].getHostName());
-      assertEquals(badHostname, info[1].getHostName());
+      assertEquals(bogusIp, info[1].getHostName());
+    }
+  }
+
+  @Test(timeout=360000)
+  public void testDuplicateHostsEntries() throws IOException,
+      InterruptedException {
+    Configuration hdfsConf = new Configuration(conf);
+    cluster = new MiniDFSCluster.Builder(hdfsConf)
+        .numDataNodes(1).setupHostsFile(true).build();
+    cluster.waitActive();
+    int dnPort = cluster.getDataNodes().get(0).getXferPort();
+
+    // pick some random ports that don't overlap with our DN's port
+    // or with each other.
+    Random random = new Random(System.currentTimeMillis());
+    int port1 = dnPort;
+    while (port1 == dnPort) {
+      port1 = random.nextInt(6000) + 1000;
+    }
+    int port2 = dnPort;
+    while ((port2 == dnPort) || (port2 == port1)) {
+      port2 = random.nextInt(6000) + 1000;
+    }
+
+    // Now empty hosts file and ensure the datanode is disallowed
+    // from talking to namenode, resulting in it's shutdown.
+    ArrayList<String> nodes = new ArrayList<String>();
+
+    // These entries will be de-duped by the NameNode, since they refer
+    // to the same IP address + port combo.
+    nodes.add("127.0.0.1:" + port1);
+    nodes.add("localhost:" + port1);
+    nodes.add("127.0.0.1:" + port1);
+
+    // The following entries should not be de-duped.
+    nodes.add("127.0.0.1:" + port2);
+    nodes.add("127.0.30.1:" + port1);
+    writeConfigFile(hostsFile,  nodes);
+
+    refreshNodes(cluster.getNamesystem(0), hdfsConf);
+
+    DFSClient client = getDfsClient(cluster.getNameNode(0), hdfsConf);
+    DatanodeInfo[] info = client.datanodeReport(DatanodeReportType.LIVE);
+    for (int i = 0 ; i < 5 && info.length != 0; i++) {
+      LOG.info("Waiting for datanode to be marked dead");
+      Thread.sleep(HEARTBEAT_INTERVAL * 1000);
+      info = client.datanodeReport(DatanodeReportType.LIVE);
+    }
+    assertEquals("Number of live nodes should be 0", 0, info.length);
+
+    // Test that non-live and bogus hostnames are considered "dead".
+    // The dead report should have an entry for (1) the DN  that is
+    // now considered dead because it is no longer allowed to connect
+    // and (2) the bogus entries in the hosts file.
+    DatanodeInfo deadDns[] = client.datanodeReport(DatanodeReportType.DEAD);
+    HashMap<String, DatanodeInfo> deadByXferAddr =
+        new HashMap<String, DatanodeInfo>();
+    for (DatanodeInfo dn : deadDns) {
+      LOG.info("DEAD DatanodeInfo: xferAddr = " + dn.getXferAddr() +
+          ", ipAddr = " + dn.getIpAddr() +
+          ", hostname = " + dn.getHostName());
+      deadByXferAddr.put(dn.getXferAddr(), dn);
+    }
+    // The real DataNode should be included in the list.
+    String realDnIpPort = cluster.getDataNodes().get(0).
+        getXferAddress().getAddress().getHostAddress() + ":" +
+        cluster.getDataNodes().get(0).getXferPort();
+    Assert.assertNotNull("failed to find real datanode IP " + realDnIpPort,
+        deadByXferAddr.remove(realDnIpPort));
+    // The fake datanode with address 127.0.30.1 should be included in this list.
+    Assert.assertNotNull(deadByXferAddr.remove(
+        "127.0.30.1:" + port1));
+    // Now look for the two copies of 127.0.0.1 with port1 and port2.
+    Iterator<Map.Entry<String, DatanodeInfo>> iter =
+            deadByXferAddr.entrySet().iterator();
+    boolean foundPort1 = false, foundPort2 = false;
+    while (iter.hasNext()) {
+      Map.Entry<String, DatanodeInfo> entry = iter.next();
+      DatanodeInfo dn = entry.getValue();
+      if (dn.getXferPort() == port1) {
+        foundPort1 = true;
+        iter.remove();
+      } else if (dn.getXferPort() == port2) {
+        foundPort2 = true;
+        iter.remove();
+      }
+    }
+    Assert.assertTrue("did not find a dead entry with port " + port1,
+        foundPort1);
+    Assert.assertTrue("did not find a dead entry with port " + port2,
+        foundPort2);
+    Assert.assertTrue(deadByXferAddr.isEmpty());
+  }
+
+  @Test(timeout=360000)
+  public void testIncludeByRegistrationName() throws IOException,
+      InterruptedException {
+    Configuration hdfsConf = new Configuration(conf);
+    final String registrationName = "--registration-name--";
+    final String nonExistentDn = "127.0.0.40";
+    hdfsConf.set(DFSConfigKeys.DFS_DATANODE_HOST_NAME_KEY, registrationName);
+    cluster = new MiniDFSCluster.Builder(hdfsConf)
+        .numDataNodes(1).checkDataNodeHostConfig(true)
+        .setupHostsFile(true).build();
+    cluster.waitActive();
+
+    // Set up an includes file that doesn't have our datanode.
+    ArrayList<String> nodes = new ArrayList<String>();
+    nodes.add(nonExistentDn);
+    writeConfigFile(hostsFile,  nodes);
+    refreshNodes(cluster.getNamesystem(0), hdfsConf);
+
+    // Wait for the DN to be marked dead.
+    DFSClient client = getDfsClient(cluster.getNameNode(0), hdfsConf);
+    while (true) {
+      DatanodeInfo info[] = client.datanodeReport(DatanodeReportType.DEAD);
+      if (info.length == 1) {
+        break;
+      }
+      LOG.info("Waiting for datanode to be marked dead");
+      Thread.sleep(HEARTBEAT_INTERVAL * 1000);
+    }
+
+    // Use a non-empty include file with our registration name.
+    // It should work.
+    int dnPort = cluster.getDataNodes().get(0).getXferPort();
+    nodes = new ArrayList<String>();
+    nodes.add(registrationName + ":" + dnPort);
+    writeConfigFile(hostsFile,  nodes);
+    refreshNodes(cluster.getNamesystem(0), hdfsConf);
+    cluster.restartDataNode(0);
+
+    // Wait for the DN to come back.
+    while (true) {
+      DatanodeInfo info[] = client.datanodeReport(DatanodeReportType.LIVE);
+      if (info.length == 1) {
+        Assert.assertFalse(info[0].isDecommissioned());
+        Assert.assertFalse(info[0].isDecommissionInProgress());
+        assertEquals(registrationName, info[0].getHostName());
+        break;
+      }
+      LOG.info("Waiting for datanode to come back");
+      Thread.sleep(HEARTBEAT_INTERVAL * 1000);
     }
   }
 }