HDFS-4988. Datanode must support all the volumes as individual storages.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/HDFS-2832@1526969 13f79535-47bb-0310-9956-ffa450edef68

hadoop-hdfs-project/hadoop-hdfs/CHANGES_HDFS-2832.txt

@@ -33,3 +33,6 @@ IMPROVEMENTS:
 
     HDFS-5222. Move block schedule information from DatanodeDescriptor to
     DatanodeStorageInfo.  (szetszwo)
+
+    HDFS-4988. Datanode must support all the volumes as individual storages.
+    (Arpit Agarwal)

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

@@ -106,7 +106,9 @@ public class LayoutVersion {
     SEQUENTIAL_BLOCK_ID(-46, "Allocate block IDs sequentially and store " +
         "block IDs in the edits log and image files"),
     EDITLOG_SUPPORT_RETRYCACHE(-47, "Record ClientId and CallId in editlog to " 
-        + "enable rebuilding retry cache in case of HA failover");
+        + "enable rebuilding retry cache in case of HA failover"),
+    DATANODE_ID(-48, "UUID per Datanode and distinct StorageID per storage "
+        + "directory.");
     
     final int lv;
     final int ancestorLV;

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

@@ -231,11 +231,14 @@ public class PBHelper {
   }
 
   public static DatanodeIDProto convert(DatanodeID dn) {
+    // For wire compatibility with older versions we transmit the StorageID
+    // which is the same as the DatanodeUuid. Since StorageID is a required
+    // field we pass the empty string if the DatanodeUuid is not yet known.
     return DatanodeIDProto.newBuilder()
         .setIpAddr(dn.getIpAddr())
         .setHostName(dn.getHostName())
-        .setDatanodeUuid(dn.getDatanodeUuid())
         .setXferPort(dn.getXferPort())
+        .setDatanodeUuid(dn.getDatanodeUuid() != null ? dn.getDatanodeUuid() : "")
         .setInfoPort(dn.getInfoPort())
         .setIpcPort(dn.getIpcPort()).build();
   }

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

@@ -420,6 +420,10 @@ public class DatanodeManager {
 
   /** Get a datanode descriptor given corresponding DatanodeUUID */
   DatanodeDescriptor getDatanode(final String datanodeUuid) {
+    if (datanodeUuid == null) {
+      return null;
+    }
+
     return datanodeMap.get(datanodeUuid);
   }
 
@@ -776,7 +780,7 @@ public class DatanodeManager {
       NameNode.stateChangeLog.info("BLOCK* registerDatanode: from "
           + nodeReg + " storage " + nodeReg.getDatanodeUuid());
   
-      DatanodeDescriptor nodeS = datanodeMap.get(nodeReg.getDatanodeUuid());
+      DatanodeDescriptor nodeS = getDatanode(nodeReg.getDatanodeUuid());
       DatanodeDescriptor nodeN = host2DatanodeMap.getDatanodeByXferAddr(
           nodeReg.getIpAddr(), nodeReg.getXferPort());
         
@@ -845,11 +849,11 @@ public class DatanodeManager {
         return;
       }
 
-      // this is a new datanode serving a new data storage
+      // This is a new datanode.
-      if ("".equals(nodeReg.getDatanodeUuid())) {
+      if (nodeReg.getDatanodeUuid() == null ||
-        // this data storage has never been registered
+          nodeReg.getDatanodeUuid().isEmpty()) {
-        // it is either empty or was created by pre-storageID version of DFS
+        // this data node has never been registered
-        nodeReg.setDatanodeUuid(DatanodeStorage.newStorageID());
+        nodeReg.generateNewDatanodeUuid();
         if (NameNode.stateChangeLog.isDebugEnabled()) {
           NameNode.stateChangeLog.debug(
               "BLOCK* NameSystem.registerDatanode: "

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/common/Storage.java

@@ -237,6 +237,9 @@ public abstract class Storage extends StorageInfo {
     final StorageDirType dirType; // storage dir type
     FileLock lock;                // storage lock
 
+    //TODO HDFS-2832: Consider moving this out of StorageDirectory.
+    String storageUuid = null;      // Storage directory identifier.
+    
     public StorageDirectory(File dir) {
       // default dirType is null
       this(dir, null, true);
@@ -246,6 +249,14 @@ public abstract class Storage extends StorageInfo {
       this(dir, dirType, true);
     }
     
+    public void setStorageUuid(String storageUuid) {
+      this.storageUuid = storageUuid;
+    }
+
+    public String getStorageUuid() {
+      return storageUuid;
+    }
+
     /**
      * Constructor
      * @param dir directory corresponding to the storage

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

@@ -23,6 +23,7 @@ import java.io.IOException;
 import java.net.InetSocketAddress;
 import java.net.SocketTimeoutException;
 import java.util.Collection;
+import java.util.Iterator;
 import java.util.Map;
 
 import org.apache.commons.logging.Log;
@@ -257,6 +258,7 @@ class BPServiceActor implements Runnable {
   
   /**
    * Report received blocks and delete hints to the Namenode
+   * TODO: Fix reportReceivedDeletedBlocks to send reports per-volume.
    * 
    * @throws IOException
    */
@@ -388,23 +390,40 @@ class BPServiceActor implements Runnable {
       // a FINALIZED one.
       reportReceivedDeletedBlocks();
 
+      // Send one block report per known storage.
+
       // Create block report
       long brCreateStartTime = now();
-      BlockListAsLongs bReport = dn.getFSDataset().getBlockReport(
+      long totalBlockCount = 0;
-          bpos.getBlockPoolId());
+
+      Map<String, BlockListAsLongs> perVolumeBlockLists =
+          dn.getFSDataset().getBlockReports(bpos.getBlockPoolId());
 
       // Send block report
       long brSendStartTime = now();
-      StorageBlockReport[] report = { new StorageBlockReport(
+      StorageBlockReport[] reports =
-          new DatanodeStorage(bpRegistration.getDatanodeUuid()),
+          new StorageBlockReport[perVolumeBlockLists.size()];
-          bReport.getBlockListAsLongs()) };
+
-      cmd = bpNamenode.blockReport(bpRegistration, bpos.getBlockPoolId(), report);
+      int i = 0;
+      for(Map.Entry<String, BlockListAsLongs> kvPair : perVolumeBlockLists.entrySet()) {
+        String storageID = kvPair.getKey();
+        BlockListAsLongs blockList = kvPair.getValue();
+        totalBlockCount += blockList.getNumberOfBlocks();
+
+        // Dummy DatanodeStorage object just for sending the block report.
+        DatanodeStorage dnStorage = new DatanodeStorage(storageID);
+        reports[i++] =
+            new StorageBlockReport(
+              dnStorage, blockList.getBlockListAsLongs());
+      }
+
+      cmd = bpNamenode.blockReport(bpRegistration, bpos.getBlockPoolId(), reports);
 
       // Log the block report processing stats from Datanode perspective
       long brSendCost = now() - brSendStartTime;
       long brCreateCost = brSendStartTime - brCreateStartTime;
       dn.getMetrics().addBlockReport(brSendCost);
-      LOG.info("BlockReport of " + bReport.getNumberOfBlocks()
+      LOG.info("BlockReport of " + totalBlockCount
           + " blocks took " + brCreateCost + " msec to generate and "
           + brSendCost + " msecs for RPC and NN processing");
 

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

@@ -750,7 +750,7 @@ public class DataNode extends Configured
     }
     DatanodeID dnId = new DatanodeID(
         streamingAddr.getAddress().getHostAddress(), hostName, 
-        getDatanodeUuid(), getXferPort(), getInfoPort(), getIpcPort());
+        storage.getDatanodeUuid(), getXferPort(), getInfoPort(), getIpcPort());
     return new DatanodeRegistration(dnId, storageInfo, 
         new ExportedBlockKeys(), VersionInfo.getVersion());
   }
@@ -768,16 +768,16 @@ public class DataNode extends Configured
       id = bpRegistration;
     }
 
-    if (storage.getStorageID().equals("")) {
+    if (storage.getDatanodeUuid() == null) {
-      // This is a fresh datanode, persist the NN-provided storage ID
+      // This is a fresh datanode, persist the NN-provided Datanode ID
-      storage.setStorageID(bpRegistration.getDatanodeUuid());
+      storage.setDatanodeUuid(bpRegistration.getDatanodeUuid());
       storage.writeAll();
-      LOG.info("New storage id " + bpRegistration.getDatanodeUuid()
+      LOG.info("Datanode ID " + bpRegistration.getDatanodeUuid()
-          + " is assigned to data-node " + bpRegistration);
+          + " is assigned to new storage " + bpRegistration);
-    } else if(!storage.getStorageID().equals(bpRegistration.getDatanodeUuid())) {
+    } else if(!storage.getDatanodeUuid().equals(bpRegistration.getDatanodeUuid())) {
-      throw new IOException("Inconsistent storage IDs. Name-node returned "
+      throw new IOException("Inconsistent Datanode IDs. Name-node returned "
           + bpRegistration.getDatanodeUuid()
-          + ". Expecting " + storage.getStorageID());
+          + ". Expecting " + storage.getDatanodeUuid());
     }
     
     registerBlockPoolWithSecretManager(bpRegistration, blockPoolId);
@@ -925,10 +925,6 @@ public class DataNode extends Configured
     return streamingAddr.getPort();
   }
   
-  String getDatanodeUuid() {
-    return storage.getStorageID();
-  }
-
   /**
    * @return name useful for logging
    */
@@ -1014,11 +1010,6 @@ public class DataNode extends Configured
     return metrics;
   }
   
-  public static void setNewStorageID(DatanodeID dnId) {
-    LOG.info("Datanode is " + dnId);
-    dnId.setDatanodeUuid(DatanodeStorage.newStorageID());
-  }
-  
   /** Ensure the authentication method is kerberos */
   private void checkKerberosAuthMethod(String msg) throws IOException {
     // User invoking the call must be same as the datanode user
@@ -1818,7 +1809,7 @@ public class DataNode extends Configured
   @Override
   public String toString() {
     return "DataNode{data=" + data + ", localName='" + getDisplayName()
-        + "', storageID='" + getDatanodeUuid() + "', xmitsInProgress="
+        + "', datanodeUuid='" + storage.getDatanodeUuid() + "', xmitsInProgress="
         + xmitsInProgress.get() + "}";
   }
 
@@ -1872,7 +1863,6 @@ public class DataNode extends Configured
   }
 
   /**
-   * This method is used for testing. 
    * Examples are adding and deleting blocks directly.
    * The most common usage will be when the data node's storage is simulated.
    * 
@@ -2425,6 +2415,10 @@ public class DataNode extends Configured
     return dnConf;
   }
 
+  public String getDatanodeUuid() {
+    return id == null ? null : id.getDatanodeUuid();
+  }
+
   boolean shouldRun() {
     return shouldRun;
   }

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

@@ -24,13 +24,7 @@ import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.RandomAccessFile;
 import java.nio.channels.FileLock;
-import java.util.ArrayList;
+import java.util.*;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.Iterator;
-import java.util.Map;
-import java.util.Properties;
 
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.conf.Configuration;
@@ -72,8 +66,13 @@ public class DataStorage extends Storage {
   public final static String STORAGE_DIR_FINALIZED = "finalized";
   public final static String STORAGE_DIR_TMP = "tmp";
 
-  /** Unique storage ID. {@see DataNode#createNewStorageId(int)} for details */
+  /**
-  private String storageID;
+   * Datanode UUID that this storage is currently attached to. This
+   *  is the same as the legacy StorageID for datanodes that were
+   *  upgraded from a pre-UUID version. For compatibility with prior
+   *  versions of Datanodes we cannot make this field a UUID.
+   */
+  private String datanodeUuid = null;
 
   // Flag to ensure we only initialize storage once
   private boolean initialized = false;
@@ -85,33 +84,29 @@ public class DataStorage extends Storage {
 
   DataStorage() {
     super(NodeType.DATA_NODE);
-    storageID = "";
   }
   
   public StorageInfo getBPStorage(String bpid) {
     return bpStorageMap.get(bpid);
   }
   
-  public DataStorage(StorageInfo storageInfo, String strgID) {
+  public DataStorage(StorageInfo storageInfo) {
     super(NodeType.DATA_NODE, storageInfo);
-    this.storageID = strgID;
   }
 
-  /** @return storage ID. */
+  public synchronized String getDatanodeUuid() {
-  public synchronized String getStorageID() {
+    return datanodeUuid;
-    return storageID;
   }
   
-  synchronized void setStorageID(String newStorageID) {
+  synchronized void setDatanodeUuid(String newDatanodeUuid) {
-    this.storageID = newStorageID;
+    this.datanodeUuid = newDatanodeUuid;
   }
 
   /** Create an ID for this storage. */
-  public synchronized void createStorageID() {
+  public synchronized void createStorageID(StorageDirectory sd) {
-    if (storageID != null && !storageID.isEmpty()) {
+    if (sd.getStorageUuid() == null) {
-      return;
+      sd.setStorageUuid(DatanodeStorage.newStorageID());
     }
-    storageID = DatanodeStorage.newStorageID();
   }
   
   /**
@@ -164,7 +159,7 @@ public class DataStorage extends Storage {
         case NOT_FORMATTED: // format
           LOG.info("Storage directory " + dataDir + " is not formatted");
           LOG.info("Formatting ...");
-          format(sd, nsInfo);
+          format(sd, nsInfo, datanode.getDatanodeUuid());
           break;
         default:  // recovery part is common
           sd.doRecover(curState);
@@ -193,11 +188,9 @@ public class DataStorage extends Storage {
       doTransition(datanode, getStorageDir(idx), nsInfo, startOpt);
       assert this.getLayoutVersion() == nsInfo.getLayoutVersion() :
         "Data-node and name-node layout versions must be the same.";
+      createStorageID(getStorageDir(idx));
     }
     
-    // make sure we have storage id set - if not - generate new one
-    createStorageID();
-    
     // 3. Update all storages. Some of them might have just been formatted.
     this.writeAll();
     
@@ -265,19 +258,28 @@ public class DataStorage extends Storage {
     }
   }
 
-  void format(StorageDirectory sd, NamespaceInfo nsInfo) throws IOException {
+  void format(StorageDirectory sd, NamespaceInfo nsInfo,
+              String datanodeUuid) throws IOException {
     sd.clearDirectory(); // create directory
     this.layoutVersion = HdfsConstants.LAYOUT_VERSION;
     this.clusterID = nsInfo.getClusterID();
     this.namespaceID = nsInfo.getNamespaceID();
     this.cTime = 0;
-    // store storageID as it currently is
+    this.datanodeUuid = datanodeUuid;
+
+    if (sd.getStorageUuid() == null) {
+      // Assign a new Storage UUID.
+      sd.setStorageUuid(UUID.randomUUID().toString());
+    }
+
     writeProperties(sd);
   }
 
   /*
    * Set ClusterID, StorageID, StorageType, CTime into
-   * DataStorage VERSION file
+   * DataStorage VERSION file.
+   * Always called just before writing the properties to
+   * the VERSION file.
   */
   @Override
   protected void setPropertiesFromFields(Properties props, 
@@ -287,7 +289,13 @@ public class DataStorage extends Storage {
     props.setProperty("clusterID", clusterID);
     props.setProperty("cTime", String.valueOf(cTime));
     props.setProperty("layoutVersion", String.valueOf(layoutVersion));
-    props.setProperty("storageID", getStorageID());
+    props.setProperty("storageID", sd.getStorageUuid());
+
+    if (LayoutVersion.supports(Feature.DATANODE_ID, layoutVersion) &&
+        datanodeUuid != null) {
+      props.setProperty("datanodeUuid", datanodeUuid);
+    }
+
     // Set NamespaceID in version before federation
     if (!LayoutVersion.supports(Feature.FEDERATION, layoutVersion)) {
       props.setProperty("namespaceID", String.valueOf(namespaceID));
@@ -297,6 +305,8 @@ public class DataStorage extends Storage {
   /*
    * Read ClusterID, StorageID, StorageType, CTime from 
    * DataStorage VERSION file and verify them.
+   * Always called just after reading the properties from the VERSION
+   * file.
    */
   @Override
   protected void setFieldsFromProperties(Properties props, StorageDirectory sd)
@@ -311,20 +321,36 @@ public class DataStorage extends Storage {
       setNamespaceID(props, sd);
     }
     
+
     // valid storage id, storage id may be empty
     String ssid = props.getProperty("storageID");
     if (ssid == null) {
       throw new InconsistentFSStateException(sd.getRoot(), "file "
           + STORAGE_FILE_VERSION + " is invalid.");
     }
-    String sid = getStorageID();
+    String sid = sd.getStorageUuid();
-    if (!(sid.equals("") || ssid.equals("") || sid.equals(ssid))) {
+    if (!(sid == null || sid.equals("") ||
+          ssid.equals("") || sid.equals(ssid))) {
       throw new InconsistentFSStateException(sd.getRoot(),
           "has incompatible storage Id.");
     }
 
-    if (sid.equals("")) { // update id only if it was empty
+    if (sid == null) { // update id only if it was null
-      setStorageID(ssid);
+      sd.setStorageUuid(ssid);
+    }
+
+    // Update the datanode UUID if present.
+    if (props.getProperty("datanodeUuid") != null) {
+      String dnUuid = props.getProperty("datanodeUuid");
+
+      if (getDatanodeUuid() == null) {
+        setDatanodeUuid(dnUuid);
+      } else if (getDatanodeUuid().compareTo(dnUuid) != 0) {
+        throw new InconsistentFSStateException(sd.getRoot(),
+            "Root " + sd.getRoot() + ": DatanodeUuid=" + dnUuid +
+            ", does not match " + datanodeUuid + " from other" +
+            " StorageDirectory.");
+      }
     }
   }
 

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

@@ -92,9 +92,6 @@ public interface FsDatasetSpi<V extends FsVolumeSpi> extends FSDatasetMBean {
   /** @return a volume information map (name => info). */
   public Map<String, Object> getVolumeInfoMap();
 
-  /** @return a list of block pools. */
-  public String[] getBlockPoolList();
-
   /** @return a list of finalized blocks for the given block pool. */
   public List<Block> getFinalizedBlocks(String bpid);
 
@@ -262,6 +259,7 @@ public interface FsDatasetSpi<V extends FsVolumeSpi> extends FSDatasetMBean {
   public void unfinalizeBlock(ExtendedBlock b) throws IOException;
 
   /**
+   * TODO HDFS-2832: Deprecate this when we fix tests.
    * Returns the block report - the full list of blocks stored under a 
    * block pool
    * @param bpid Block Pool Id
@@ -269,6 +267,13 @@ public interface FsDatasetSpi<V extends FsVolumeSpi> extends FSDatasetMBean {
    */
   public BlockListAsLongs getBlockReport(String bpid);
 
+  /**
+   * Returns one block report per volume.
+   * @param bpid Block Pool Id
+   * @return - a map of StorageID to block report for the volume.
+   */
+  public Map<String, BlockListAsLongs> getBlockReports(String bpid);
+
   /** Does the dataset contain the block? */
   public boolean contains(ExtendedBlock block);
 

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/FsDatasetImpl.java

@@ -43,7 +43,6 @@ import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.hdfs.DFSConfigKeys;
-import org.apache.hadoop.hdfs.DFSUtil;
 import org.apache.hadoop.hdfs.StorageType;
 import org.apache.hadoop.hdfs.protocol.Block;
 import org.apache.hadoop.hdfs.protocol.BlockListAsLongs;
@@ -53,6 +52,7 @@ import org.apache.hadoop.hdfs.protocol.HdfsBlocksMetadata;
 import org.apache.hadoop.hdfs.protocol.RecoveryInProgressException;
 import org.apache.hadoop.hdfs.server.common.GenerationStamp;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.ReplicaState;
+import org.apache.hadoop.hdfs.server.common.Storage;
 import org.apache.hadoop.hdfs.server.datanode.BlockMetadataHeader;
 import org.apache.hadoop.hdfs.server.datanode.DataBlockScanner;
 import org.apache.hadoop.hdfs.server.datanode.DataNode;
@@ -170,10 +170,16 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
     
   final DataNode datanode;
   final FsVolumeList volumes;
-  final ReplicaMap volumeMap;
   final FsDatasetAsyncDiskService asyncDiskService;
   private final int validVolsRequired;
 
+  // TODO HDFS-2832: Consider removing duplicated block info from these
+  //                 two maps. This might require some refactoring
+  //                 rewrite of FsDatasetImpl.
+  final ReplicaMap volumeMap;
+  final Map<FsVolumeImpl, ReplicaMap> perVolumeReplicaMap;
+
+
   // Used for synchronizing access to usage stats
   private final Object statsLock = new Object();
 
@@ -211,16 +217,18 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
     final List<FsVolumeImpl> volArray = new ArrayList<FsVolumeImpl>(
         storage.getNumStorageDirs());
     for (int idx = 0; idx < storage.getNumStorageDirs(); idx++) {
-      final File dir = storage.getStorageDir(idx).getCurrentDir();
       // TODO: getStorageTypeFromLocations() is only a temporary workaround and 
       // should be replaced with getting storage type from DataStorage (missing 
       // storage type now) directly.
+      Storage.StorageDirectory sd = storage.getStorageDir(idx);
+      final File dir = sd.getCurrentDir();
       final StorageType storageType = getStorageTypeFromLocations(dataLocations, dir);
-      volArray.add(new FsVolumeImpl(this, storage.getStorageID(), dir, conf,
+      volArray.add(new FsVolumeImpl(this, sd.getStorageUuid(), dir, conf,
           storageType));
       LOG.info("Added volume - " + dir + ", StorageType: " + storageType);
     }
     volumeMap = new ReplicaMap(this);
+    perVolumeReplicaMap = new HashMap<FsVolumeImpl, ReplicaMap>();
 
     @SuppressWarnings("unchecked")
     final VolumeChoosingPolicy<FsVolumeImpl> blockChooserImpl =
@@ -229,14 +237,14 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
             RoundRobinVolumeChoosingPolicy.class,
             VolumeChoosingPolicy.class), conf);
     volumes = new FsVolumeList(volArray, volsFailed, blockChooserImpl);
-    volumes.getVolumeMap(volumeMap);
+    volumes.initializeReplicaMaps(perVolumeReplicaMap, volumeMap, this);
 
     File[] roots = new File[storage.getNumStorageDirs()];
     for (int idx = 0; idx < storage.getNumStorageDirs(); idx++) {
       roots[idx] = storage.getStorageDir(idx).getCurrentDir();
     }
     asyncDiskService = new FsDatasetAsyncDiskService(datanode, roots);
-    registerMBean(storage.getStorageID());
+    registerMBean(datanode.getDatanodeUuid());
   }
 
   private StorageType getStorageTypeFromLocations(
@@ -326,9 +334,6 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
   File getBlockFile(String bpid, Block b) throws IOException {
     File f = validateBlockFile(bpid, b);
     if(f == null) {
-      if (LOG.isDebugEnabled()) {
-        LOG.debug("b=" + b + ", volumeMap=" + volumeMap);
-      }
       throw new IOException("Block " + b + " is not valid.");
     }
     return f;
@@ -602,6 +607,7 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
     
     // Replace finalized replica by a RBW replica in replicas map
     volumeMap.add(bpid, newReplicaInfo);
+    perVolumeReplicaMap.get(v).add(bpid, newReplicaInfo);
     
     return newReplicaInfo;
   }
@@ -731,6 +737,7 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
     ReplicaBeingWritten newReplicaInfo = new ReplicaBeingWritten(b.getBlockId(), 
         b.getGenerationStamp(), v, f.getParentFile());
     volumeMap.add(b.getBlockPoolId(), newReplicaInfo);
+    perVolumeReplicaMap.get(v).add(b.getBlockPoolId(), newReplicaInfo);
     return newReplicaInfo;
   }
   
@@ -849,6 +856,7 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
     rbw.setBytesAcked(visible);
     // overwrite the RBW in the volume map
     volumeMap.add(b.getBlockPoolId(), rbw);
+    perVolumeReplicaMap.get(v).add(b.getBlockPoolId(), rbw);
     return rbw;
   }
 
@@ -868,6 +876,7 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
     ReplicaInPipeline newReplicaInfo = new ReplicaInPipeline(b.getBlockId(), 
         b.getGenerationStamp(), v, f.getParentFile());
     volumeMap.add(b.getBlockPoolId(), newReplicaInfo);
+    perVolumeReplicaMap.get(v).add(b.getBlockPoolId(), newReplicaInfo);
     
     return newReplicaInfo;
   }
@@ -936,6 +945,7 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
       newReplicaInfo = new FinalizedReplica(replicaInfo, v, dest.getParentFile());
     }
     volumeMap.add(bpid, newReplicaInfo);
+    perVolumeReplicaMap.get(newReplicaInfo.getVolume()).add(bpid, newReplicaInfo);
     return newReplicaInfo;
   }
 
@@ -949,6 +959,8 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
     if (replicaInfo != null && replicaInfo.getState() == ReplicaState.TEMPORARY) {
       // remove from volumeMap
       volumeMap.remove(b.getBlockPoolId(), b.getLocalBlock());
+      perVolumeReplicaMap.get((FsVolumeImpl) replicaInfo.getVolume())
+          .remove(b.getBlockPoolId(), b.getLocalBlock());
       
       // delete the on-disk temp file
       if (delBlockFromDisk(replicaInfo.getBlockFile(), 
@@ -983,12 +995,9 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
     return true;
   }
 
-  /**
+  private BlockListAsLongs getBlockReportWithReplicaMap(
-   * Generates a block report from the in-memory block map.
+      String bpid, ReplicaMap rMap) {
-   */
+    int size =  rMap.size(bpid);
-  @Override // FsDatasetSpi
-  public BlockListAsLongs getBlockReport(String bpid) {
-    int size =  volumeMap.size(bpid);
     ArrayList<ReplicaInfo> finalized = new ArrayList<ReplicaInfo>(size);
     ArrayList<ReplicaInfo> uc = new ArrayList<ReplicaInfo>();
     if (size == 0) {
@@ -996,7 +1005,7 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
     }
     
     synchronized(this) {
-      for (ReplicaInfo b : volumeMap.replicas(bpid)) {
+      for (ReplicaInfo b : rMap.replicas(bpid)) {
         switch(b.getState()) {
         case FINALIZED:
           finalized.add(b);
@@ -1019,6 +1028,28 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
     }
   }
 
+  /**
+   * Generates a block report from the in-memory block map.
+   */
+  @Override // FsDatasetSpi
+  public BlockListAsLongs getBlockReport(String bpid) {
+    return getBlockReportWithReplicaMap(bpid, volumeMap);
+  }
+
+  @Override
+  public Map<String, BlockListAsLongs> getBlockReports(String bpid) {
+    Map<String, BlockListAsLongs> blockReportMap =
+        new HashMap<String, BlockListAsLongs>();
+
+    for (FsVolumeImpl v : getVolumes()) {
+      ReplicaMap rMap = perVolumeReplicaMap.get(v);
+      BlockListAsLongs blockList = getBlockReportWithReplicaMap(bpid, rMap);
+      blockReportMap.put(v.getStorageID(), blockList);
+    }
+
+    return blockReportMap;
+  }
+
   /**
    * Get the list of finalized blocks from in-memory blockmap for a block pool.
    */
@@ -1159,6 +1190,7 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
           v.clearPath(bpid, parent);
         }
         volumeMap.remove(bpid, invalidBlks[i]);
+        perVolumeReplicaMap.get(v).remove(bpid, invalidBlks[i]);
       }
 
       // Delete the block asynchronously to make sure we can do it fast enough
@@ -1220,6 +1252,7 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
               LOG.warn("Removing replica " + bpid + ":" + b.getBlockId()
                   + " on failed volume " + fv.getCurrentDir().getAbsolutePath());
               ib.remove();
+              perVolumeReplicaMap.get(fv).remove(bpid, b.getBlockId());
               removedBlocks++;
             }
           }
@@ -1248,22 +1281,15 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
   
   /**
    * Register the FSDataset MBean using the name
-   *        "hadoop:service=DataNode,name=FSDatasetState-<storageid>"
+   *        "hadoop:service=DataNode,name=FSDatasetState-<datanodeUuid>"
    */
-  void registerMBean(final String storageId) {
+  void registerMBean(final String datanodeUuid) {
     // We wrap to bypass standard mbean naming convetion.
     // This wraping can be removed in java 6 as it is more flexible in 
     // package naming for mbeans and their impl.
-    StandardMBean bean;
-    String storageName;
-    if (storageId == null || storageId.equals("")) {// Temp fix for the uninitialized storage
-      storageName = "UndefinedStorageId" + DFSUtil.getRandom().nextInt();
-    } else {
-      storageName = storageId;
-    }
     try {
-      bean = new StandardMBean(this,FSDatasetMBean.class);
+      StandardMBean bean = new StandardMBean(this,FSDatasetMBean.class);
-      mbeanName = MBeans.register("DataNode", "FSDatasetState-" + storageName, bean);
+      mbeanName = MBeans.register("DataNode", "FSDatasetState-" + datanodeUuid, bean);
     } catch (NotCompliantMBeanException e) {
       LOG.warn("Error registering FSDatasetState MBean", e);
     }
@@ -1343,6 +1369,8 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
           // Block is in memory and not on the disk
           // Remove the block from volumeMap
           volumeMap.remove(bpid, blockId);
+          perVolumeReplicaMap.get((FsVolumeImpl) memBlockInfo.getVolume())
+              .remove(bpid, blockId);
           final DataBlockScanner blockScanner = datanode.getBlockScanner();
           if (blockScanner != null) {
             blockScanner.deleteBlock(bpid, new Block(blockId));
@@ -1366,6 +1394,8 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
         ReplicaInfo diskBlockInfo = new FinalizedReplica(blockId, 
             diskFile.length(), diskGS, vol, diskFile.getParentFile());
         volumeMap.add(bpid, diskBlockInfo);
+        perVolumeReplicaMap.get((FsVolumeImpl) memBlockInfo.getVolume()).
+            remove(bpid, diskBlockInfo);
         final DataBlockScanner blockScanner = datanode.getBlockScanner();
         if (blockScanner != null) {
           blockScanner.addBlock(new ExtendedBlock(bpid, diskBlockInfo));
@@ -1639,7 +1669,14 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
     LOG.info("Adding block pool " + bpid);
     volumes.addBlockPool(bpid, conf);
     volumeMap.initBlockPool(bpid);
-    volumes.getVolumeMap(bpid, volumeMap);
+    volumes.getAllVolumesMap(bpid, volumeMap);
+
+    // TODO: Avoid the double scan.
+    for (FsVolumeImpl v : getVolumes()) {
+      ReplicaMap rMap = perVolumeReplicaMap.get(v);
+      rMap.initBlockPool(bpid);
+      volumes.getVolumeMap(bpid, v, rMap);
+    }
   }
 
   @Override
@@ -1649,11 +1686,6 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
     volumes.removeBlockPool(bpid);
   }
   
-  @Override
-  public String[] getBlockPoolList() {
-    return volumeMap.getBlockPoolList();
-  }
-  
   /**
    * Class for representing the Datanode volume information
    */

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/FsVolumeImpl.java

@@ -290,7 +290,7 @@ class FsVolumeImpl implements FsVolumeSpi {
     }
   }
 
-  String getStorageID() {
+  public String getStorageID() {
     return storageID;
   }
   

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/FsVolumeList.java

@@ -18,10 +18,7 @@
 package org.apache.hadoop.hdfs.server.datanode.fsdataset.impl;
 
 import java.io.IOException;
-import java.util.ArrayList;
+import java.util.*;
-import java.util.Collections;
-import java.util.Iterator;
-import java.util.List;
 
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsVolumeSpi;
@@ -93,28 +90,38 @@ class FsVolumeList {
     return remaining;
   }
     
-  void getVolumeMap(ReplicaMap volumeMap) throws IOException {
+  void initializeReplicaMaps(Map<FsVolumeImpl, ReplicaMap> perVolumeReplicaMap,
+                             ReplicaMap globalReplicaMap,
+                             Object mutex) throws IOException {
     for (FsVolumeImpl v : volumes) {
-      v.getVolumeMap(volumeMap);
+      ReplicaMap rMap = new ReplicaMap(mutex);
+      v.getVolumeMap(rMap);
+      perVolumeReplicaMap.put(v, rMap);
+      globalReplicaMap.addAll(rMap);
     }
   }
   
-  void getVolumeMap(String bpid, ReplicaMap volumeMap) throws IOException {
+  void getAllVolumesMap(String bpid, ReplicaMap volumeMap) throws IOException {
     long totalStartTime = System.currentTimeMillis();
     for (FsVolumeImpl v : volumes) {
-      FsDatasetImpl.LOG.info("Adding replicas to map for block pool " + bpid +
+      getVolumeMap(bpid, v, volumeMap);
-          " on volume " + v + "...");
-      long startTime = System.currentTimeMillis();
-      v.getVolumeMap(bpid, volumeMap);
-      long timeTaken = System.currentTimeMillis() - startTime;
-      FsDatasetImpl.LOG.info("Time to add replicas to map for block pool " + bpid +
-          " on volume " + v + ": " + timeTaken + "ms");
     }
     long totalTimeTaken = System.currentTimeMillis() - totalStartTime;
     FsDatasetImpl.LOG.info("Total time to add all replicas to map: "
         + totalTimeTaken + "ms");
   }
 
+  void getVolumeMap(String bpid, FsVolumeImpl volume, ReplicaMap volumeMap)
+      throws IOException {
+    FsDatasetImpl.LOG.info("Adding replicas to map for block pool " + bpid +
+                               " on volume " + volume + "...");
+    long startTime = System.currentTimeMillis();
+    volume.getVolumeMap(bpid, volumeMap);
+    long timeTaken = System.currentTimeMillis() - startTime;
+    FsDatasetImpl.LOG.info("Time to add replicas to map for block pool " + bpid +
+                               " on volume " + volume + ": " + timeTaken + "ms");
+  }
+    
   /**
    * Calls {@link FsVolumeImpl#checkDirs()} on each volume, removing any
    * volumes from the active list that result in a DiskErrorException.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/ReplicaMap.java

@@ -118,6 +118,15 @@ class ReplicaMap {
     }
   }
 
+  /**
+   * Add all entries from the given replica map into the local replica
+   * map.
+   * @param
+   */
+  void addAll(ReplicaMap other) {
+    map.putAll(other.map);
+  }
+  
   /**
    * Remove the replica's meta information from the map that matches
    * the input block's id and generation stamp

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/JsonUtil.java

@@ -289,6 +289,7 @@ public class JsonUtil {
       return null;
     }
 
+    // TODO: Fix storageID
     final Map<String, Object> m = new TreeMap<String, Object>();
     m.put("ipAddr", datanodeinfo.getIpAddr());
     m.put("hostName", datanodeinfo.getHostName());
@@ -314,6 +315,7 @@ public class JsonUtil {
       return null;
     }
 
+    // TODO: Fix storageID
     return new DatanodeInfo(
         (String)m.get("ipAddr"),
         (String)m.get("hostName"),

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

@@ -41,13 +41,7 @@ import java.net.Socket;
 import java.net.URL;
 import java.net.URLConnection;
 import java.security.PrivilegedExceptionAction;
-import java.util.ArrayList;
+import java.util.*;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Map;
-import java.util.Random;
-import java.util.Set;
 import java.util.concurrent.TimeoutException;
 
 import org.apache.commons.logging.Log;
@@ -805,7 +799,8 @@ public class DFSTestUtil {
   }
   
   private static DatanodeID getDatanodeID(String ipAddr) {
-    return new DatanodeID(ipAddr, "localhost", "",
+    return new DatanodeID(ipAddr, "localhost",
+        UUID.randomUUID().toString(),
         DFSConfigKeys.DFS_DATANODE_DEFAULT_PORT,
         DFSConfigKeys.DFS_DATANODE_HTTP_DEFAULT_PORT,
         DFSConfigKeys.DFS_DATANODE_IPC_DEFAULT_PORT);
@@ -816,8 +811,8 @@ public class DFSTestUtil {
   }
 
   public static DatanodeID getLocalDatanodeID(int port) {
-    return new DatanodeID("127.0.0.1", "localhost", "",
+    return new DatanodeID("127.0.0.1", "localhost",
-        port, port, port);
+        UUID.randomUUID().toString(), port, port, port);
   }
 
   public static DatanodeDescriptor getLocalDatanodeDescriptor() {
@@ -838,8 +833,9 @@ public class DFSTestUtil {
 
   public static DatanodeInfo getDatanodeInfo(String ipAddr, 
       String host, int port) {
-    return new DatanodeInfo(new DatanodeID(ipAddr, host, "",
+    return new DatanodeInfo(new DatanodeID(ipAddr, host,
-        port, DFSConfigKeys.DFS_DATANODE_HTTP_DEFAULT_PORT,
+        UUID.randomUUID().toString(), port,
+        DFSConfigKeys.DFS_DATANODE_HTTP_DEFAULT_PORT,
         DFSConfigKeys.DFS_DATANODE_IPC_DEFAULT_PORT));
   }
 
@@ -893,7 +889,8 @@ public class DFSTestUtil {
 
   public static DatanodeDescriptor getDatanodeDescriptor(String ipAddr,
       int port, String rackLocation) {
-    DatanodeID dnId = new DatanodeID(ipAddr, "host", "", port,
+    DatanodeID dnId = new DatanodeID(ipAddr, "host",
+        UUID.randomUUID().toString(), port,
         DFSConfigKeys.DFS_DATANODE_HTTP_DEFAULT_PORT,
         DFSConfigKeys.DFS_DATANODE_IPC_DEFAULT_PORT);
     return new DatanodeDescriptor(dnId, rackLocation);

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

@@ -172,7 +172,7 @@ public class TestDatanodeRegistration {
 
       // register a datanode
       DatanodeID dnId = new DatanodeID(DN_IP_ADDR, DN_HOSTNAME,
-          "fake-storage-id", DN_XFER_PORT, DN_INFO_PORT, DN_IPC_PORT);
+          "fake-datanode-id", DN_XFER_PORT, DN_INFO_PORT, DN_IPC_PORT);
       long nnCTime = cluster.getNamesystem().getFSImage().getStorage()
           .getCTime();
       StorageInfo mockStorageInfo = mock(StorageInfo.class);
@@ -188,7 +188,7 @@ public class TestDatanodeRegistration {
 
       // register the same datanode again with a different storage ID
       dnId = new DatanodeID(DN_IP_ADDR, DN_HOSTNAME,
-          "changed-fake-storage-id", DN_XFER_PORT, DN_INFO_PORT, DN_IPC_PORT);
+          "changed-fake-datanode-id", DN_XFER_PORT, DN_INFO_PORT, DN_IPC_PORT);
       dnReg = new DatanodeRegistration(dnId,
           mockStorageInfo, null, VersionInfo.getVersion());
       rpcServer.registerDatanode(dnReg);

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

@@ -149,7 +149,7 @@ public class TestPeerCache {
   public void testAddAndRetrieve() throws Exception {
     PeerCache cache = new PeerCache(3, 100000);
     DatanodeID dnId = new DatanodeID("192.168.0.1",
-          "fakehostname", "fake_storage_id",
+          "fakehostname", "fake_datanode_id",
           100, 101, 102);
     FakePeer peer = new FakePeer(dnId, false);
     cache.put(dnId, peer);
@@ -169,7 +169,7 @@ public class TestPeerCache {
     FakePeer peers[] = new FakePeer[CAPACITY];
     for (int i = 0; i < CAPACITY; ++i) {
       dnIds[i] = new DatanodeID("192.168.0.1",
-          "fakehostname_" + i, "fake_storage_id",
+          "fakehostname_" + i, "fake_datanode_id",
           100, 101, 102);
       peers[i] = new FakePeer(dnIds[i], false);
     }
@@ -200,7 +200,7 @@ public class TestPeerCache {
     FakePeer peers[] = new FakePeer[CAPACITY + 1];
     for (int i = 0; i < dnIds.length; ++i) {
       dnIds[i] = new DatanodeID("192.168.0.1",
-          "fakehostname_" + i, "fake_storage_id_" + i,
+          "fakehostname_" + i, "fake_datanode_id_" + i,
           100, 101, 102);
       peers[i] = new FakePeer(dnIds[i], false);
     }
@@ -231,7 +231,7 @@ public class TestPeerCache {
     final int CAPACITY = 3;
     PeerCache cache = new PeerCache(CAPACITY, 100000);
     DatanodeID dnId = new DatanodeID("192.168.0.1",
-          "fakehostname", "fake_storage_id",
+          "fakehostname", "fake_datanode_id",
           100, 101, 102);
     HashMultiset<FakePeer> peers = HashMultiset.create(CAPACITY);
     for (int i = 0; i < CAPACITY; ++i) {
@@ -256,7 +256,7 @@ public class TestPeerCache {
     final int CAPACITY = 3;
     PeerCache cache = new PeerCache(CAPACITY, 100000);
     DatanodeID dnId = new DatanodeID("192.168.0.1",
-          "fakehostname", "fake_storage_id",
+          "fakehostname", "fake_datanode_id",
           100, 101, 102);
     HashMultiset<FakePeer> peers = HashMultiset.create(CAPACITY);
     for (int i = 0; i < CAPACITY; ++i) {

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

@@ -453,7 +453,7 @@ public class UpgradeUtilities {
    */
   public static void createDataNodeVersionFile(File[] parent,
       StorageInfo version, String bpid, String bpidToWrite) throws IOException {
-    DataStorage storage = new DataStorage(version, "doNotCare");
+    DataStorage storage = new DataStorage(version);
 
     File[] versionFiles = new File[parent.length];
     for (int i = 0; i < parent.length; i++) {

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/blockmanagement/TestBlockManager.java

@@ -527,6 +527,8 @@ public class TestBlockManager {
   public void testSafeModeIBR() throws Exception {
     DatanodeDescriptor node = spy(nodes.get(0));
     DatanodeStorageInfo ds = node.getStorageInfos()[0];
+
+    // TODO: Needs to be fixed. DatanodeUuid is not storageID.
     node.setDatanodeUuid(ds.getStorageID());
 
     node.isAlive = true;
@@ -571,7 +573,10 @@ public class TestBlockManager {
   public void testSafeModeIBRAfterIncremental() throws Exception {
     DatanodeDescriptor node = spy(nodes.get(0));
     DatanodeStorageInfo ds = node.getStorageInfos()[0];
+
+    // TODO: Needs to be fixed. DatanodeUuid is not storageID.
     node.setDatanodeUuid(ds.getStorageID());
+
     node.isAlive = true;
 
     DatanodeRegistration nodeReg =

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/common/TestJspHelper.java

@@ -445,9 +445,9 @@ public class TestJspHelper {
 
   @Test
   public void testSortNodeByFields() throws Exception {
-    DatanodeID dnId1 = new DatanodeID("127.0.0.1", "localhost1", "storage1",
+    DatanodeID dnId1 = new DatanodeID("127.0.0.1", "localhost1", "datanode1",
         1234, 2345, 3456);
-    DatanodeID dnId2 = new DatanodeID("127.0.0.2", "localhost2", "storage2",
+    DatanodeID dnId2 = new DatanodeID("127.0.0.2", "localhost2", "datanode2",
         1235, 2346, 3457);
     DatanodeDescriptor dnDesc1 = new DatanodeDescriptor(dnId1, "rack1", 1024,
         100, 924, 100, 10, 2);

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/SimulatedFSDataset.java

@@ -383,8 +383,10 @@ public class SimulatedFSDataset implements FsDatasetSpi<FsVolumeSpi> {
   
   public SimulatedFSDataset(DataStorage storage, Configuration conf) {
     if (storage != null) {
-      storage.createStorageID();
+      for (int i = 0; i < storage.getNumStorageDirs(); ++i) {
-      this.datanodeUuid = storage.getStorageID();
+        storage.createStorageID(storage.getStorageDir(i));
+      }
+      this.datanodeUuid = storage.getDatanodeUuid();
     } else {
       this.datanodeUuid = "unknownStorageId-" + UUID.randomUUID();
     }
@@ -459,6 +461,15 @@ public class SimulatedFSDataset implements FsDatasetSpi<FsVolumeSpi> {
     return new BlockListAsLongs(blocks, null);
   }
 
+  @Override
+  public synchronized Map<String, BlockListAsLongs> getBlockReports(
+      String bpid) {
+    Map<String, BlockListAsLongs> reports =
+        new HashMap<String, BlockListAsLongs>();
+    reports.put("", getBlockReport(bpid));
+    return reports;
+  }
+
   @Override // FSDatasetMBean
   public long getCapacity() {
     return storage.getCapacity();
@@ -910,6 +921,7 @@ public class SimulatedFSDataset implements FsDatasetSpi<FsVolumeSpi> {
   public String updateReplicaUnderRecovery(ExtendedBlock oldBlock,
                                         long recoveryId,
                                         long newlength) {
+    // Caller does not care about the exact Storage UUID returned.
     return datanodeUuid;
   }
 
@@ -964,11 +976,6 @@ public class SimulatedFSDataset implements FsDatasetSpi<FsVolumeSpi> {
     throw new UnsupportedOperationException();
   }
 
-  @Override
-  public String[] getBlockPoolList() {
-    throw new UnsupportedOperationException();
-  }
-
   @Override
   public void checkAndUpdate(String bpid, long blockId, File diskFile,
       File diskMetaFile, FsVolumeSpi vol) {

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestBlockReport.java

@@ -368,7 +368,7 @@ public class TestBlockReport {
     int randIndex = rand.nextInt(blocks.size());
     // Get a block and screw its GS
     Block corruptedBlock = blocks.get(randIndex);
-    String secondNode = cluster.getDataNodes().get(DN_N1).getDatanodeUuid();
+    String secondNode = cluster.getDataNodes().get(DN_N1).getDatanodeId().getDatanodeUuid();
     if(LOG.isDebugEnabled()) {
       LOG.debug("Working with " + secondNode);
       LOG.debug("BlockGS before " + blocks.get(randIndex).getGenerationStamp());

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/NNThroughputBenchmark.java

@@ -840,9 +840,9 @@ public class NNThroughputBenchmark implements Tool {
               "", getNodePort(dnIdx),
               DFSConfigKeys.DFS_DATANODE_HTTP_DEFAULT_PORT,
               DFSConfigKeys.DFS_DATANODE_IPC_DEFAULT_PORT),
-          new DataStorage(nsInfo, ""),
+          new DataStorage(nsInfo),
           new ExportedBlockKeys(), VersionInfo.getVersion());
-      DataNode.setNewStorageID(dnRegistration);
+      // TODO: Fix NNThroughputBenchmark.
       // register datanode
       dnRegistration = nameNodeProto.registerDatanode(dnRegistration);
       //first block reports
@@ -939,7 +939,7 @@ public class NNThroughputBenchmark implements Tool {
           DatanodeInfo dnInfo = blockTargets[t];
           DatanodeRegistration receivedDNReg;
           receivedDNReg = new DatanodeRegistration(dnInfo,
-            new DataStorage(nsInfo, dnInfo.getDatanodeUuid()),
+            new DataStorage(nsInfo),
             new ExportedBlockKeys(), VersionInfo.getVersion());
           ReceivedDeletedBlockInfo[] rdBlocks = {
             new ReceivedDeletedBlockInfo(