HDFS-5318. Support read-only and read-write paths to shared replicas. (Contributed by Eric Sirianni)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1569951 13f79535-47bb-0310-9956-ffa450edef68

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/conf/Configuration.java

@@ -765,6 +765,19 @@ public void addResource(InputStream in, String name) {
     addResourceObject(new Resource(in, name));
   }
   
+  /**
+   * Add a configuration resource.
+   *
+   * The properties of this resource will override properties of previously
+   * added resources, unless they were marked <a href="#Final">final</a>.
+   *
+   * @param conf Configuration object from which to load properties
+   */
+  public void addResource(Configuration conf) {
+    addResourceObject(new Resource(conf.getProps()));
+  }
+
+  
   
   /**
    * Reload configuration from previously added resources.

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

@@ -418,6 +418,9 @@ Release 2.4.0 - UNRELEASED
 
     HDFS-5973. add DomainSocket#shutdown method (cmccabe)
 
+    HDFS-5318. Support read-only and read-write paths to shared replicas.
+    (Eric Sirianni via Arpit Agarwal)
+
   OPTIMIZATIONS
 
     HDFS-5790. LeaseManager.findPath is very slow when many leases need recovery

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

@@ -1520,8 +1520,8 @@ public static DatanodeStorageProto convert(DatanodeStorage s) {
 
   private static StorageState convertState(State state) {
     switch(state) {
-    case READ_ONLY:
+    case READ_ONLY_SHARED:
-      return StorageState.READ_ONLY;
+      return StorageState.READ_ONLY_SHARED;
     case NORMAL:
     default:
       return StorageState.NORMAL;
@@ -1549,8 +1549,8 @@ public static DatanodeStorage convert(DatanodeStorageProto s) {
 
   private static State convertState(StorageState state) {
     switch(state) {
-    case READ_ONLY:
+    case READ_ONLY_SHARED:
-      return DatanodeStorage.State.READ_ONLY;
+      return DatanodeStorage.State.READ_ONLY_SHARED;
     case NORMAL:
     default:
       return DatanodeStorage.State.NORMAL;

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

@@ -73,6 +73,7 @@
 import org.apache.hadoop.hdfs.server.protocol.BlocksWithLocations.BlockWithLocations;
 import org.apache.hadoop.hdfs.server.protocol.DatanodeCommand;
 import org.apache.hadoop.hdfs.server.protocol.DatanodeStorage;
+import org.apache.hadoop.hdfs.server.protocol.DatanodeStorage.State;
 import org.apache.hadoop.hdfs.server.protocol.KeyUpdateCommand;
 import org.apache.hadoop.hdfs.server.protocol.ReceivedDeletedBlockInfo;
 import org.apache.hadoop.hdfs.server.protocol.StorageReceivedDeletedBlocks;
@@ -482,7 +483,10 @@ private void dumpBlockMeta(Block block, PrintWriter out) {
     chooseSourceDatanode(block, containingNodes,
         containingLiveReplicasNodes, numReplicas,
         UnderReplicatedBlocks.LEVEL);
-    assert containingLiveReplicasNodes.size() == numReplicas.liveReplicas();
+    
+    // containingLiveReplicasNodes can include READ_ONLY_SHARED replicas which are 
+    // not included in the numReplicas.liveReplicas() count
+    assert containingLiveReplicasNodes.size() >= numReplicas.liveReplicas();
     int usableReplicas = numReplicas.liveReplicas() +
                          numReplicas.decommissionedReplicas();
     
@@ -1021,7 +1025,7 @@ void addToInvalidates(final Block block, final DatanodeInfo datanode) {
    */
   private void addToInvalidates(Block b) {
     StringBuilder datanodes = new StringBuilder();
-    for(DatanodeStorageInfo storage : blocksMap.getStorages(b)) {
+    for(DatanodeStorageInfo storage : blocksMap.getStorages(b, State.NORMAL)) {
       final DatanodeDescriptor node = storage.getDatanodeDescriptor();
       invalidateBlocks.add(b, node, false);
       datanodes.append(node).append(" ");
@@ -1235,7 +1239,10 @@ int computeReplicationWorkForBlocks(List<List<Block>> blocksToReplicate) {
               continue;
             }
 
-            assert liveReplicaNodes.size() == numReplicas.liveReplicas();
+            // liveReplicaNodes can include READ_ONLY_SHARED replicas which are 
+            // not included in the numReplicas.liveReplicas() count
+            assert liveReplicaNodes.size() >= numReplicas.liveReplicas();
+
             // do not schedule more if enough replicas is already pending
             numEffectiveReplicas = numReplicas.liveReplicas() +
                                     pendingReplications.getNumReplicas(block);
@@ -1475,15 +1482,16 @@ DatanodeDescriptor chooseSourceDatanode(Block block,
       final DatanodeDescriptor node = storage.getDatanodeDescriptor();
       LightWeightLinkedSet<Block> excessBlocks =
         excessReplicateMap.get(node.getDatanodeUuid());
+      int countableReplica = storage.getState() == State.NORMAL ? 1 : 0; 
       if ((nodesCorrupt != null) && (nodesCorrupt.contains(node)))
-        corrupt++;
+        corrupt += countableReplica;
       else if (node.isDecommissionInProgress() || node.isDecommissioned())
-        decommissioned++;
+        decommissioned += countableReplica;
       else if (excessBlocks != null && excessBlocks.contains(block)) {
-        excess++;
+        excess += countableReplica;
       } else {
         nodesContainingLiveReplicas.add(storage);
-        live++;
+        live += countableReplica;
       }
       containingNodes.add(node);
       // Check if this replica is corrupt
@@ -2480,7 +2488,7 @@ private void processOverReplicatedBlock(final Block block,
     Collection<DatanodeDescriptor> nonExcess = new ArrayList<DatanodeDescriptor>();
     Collection<DatanodeDescriptor> corruptNodes = corruptReplicas
         .getNodes(block);
-    for(DatanodeStorageInfo storage : blocksMap.getStorages(block)) {
+    for(DatanodeStorageInfo storage : blocksMap.getStorages(block, State.NORMAL)) {
       final DatanodeDescriptor cur = storage.getDatanodeDescriptor();
       if (storage.areBlockContentsStale()) {
         LOG.info("BLOCK* processOverReplicatedBlock: " +
@@ -2809,7 +2817,7 @@ public NumberReplicas countNodes(Block b) {
     int excess = 0;
     int stale = 0;
     Collection<DatanodeDescriptor> nodesCorrupt = corruptReplicas.getNodes(b);
-    for(DatanodeStorageInfo storage : blocksMap.getStorages(b)) {
+    for(DatanodeStorageInfo storage : blocksMap.getStorages(b, State.NORMAL)) {
       final DatanodeDescriptor node = storage.getDatanodeDescriptor();
       if ((nodesCorrupt != null) && (nodesCorrupt.contains(node))) {
         corrupt++;
@@ -2848,7 +2856,7 @@ int countLiveNodes(BlockInfo b) {
     // else proceed with fast case
     int live = 0;
     Collection<DatanodeDescriptor> nodesCorrupt = corruptReplicas.getNodes(b);
-    for(DatanodeStorageInfo storage : blocksMap.getStorages(b)) {
+    for(DatanodeStorageInfo storage : blocksMap.getStorages(b, State.NORMAL)) {
       final DatanodeDescriptor node = storage.getDatanodeDescriptor();
       if ((nodesCorrupt == null) || (!nodesCorrupt.contains(node)))
         live++;

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

@@ -605,7 +605,7 @@ private boolean isGoodTarget(DatanodeStorageInfo storage,
               + storageType);
       return false;
     }
-    if (storage.getState() == State.READ_ONLY) {
+    if (storage.getState() == State.READ_ONLY_SHARED) {
       logNodeIsNotChosen(storage, "storage is read-only");
       return false;
     }

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

@@ -20,9 +20,13 @@
 import java.util.Iterator;
 
 import org.apache.hadoop.hdfs.protocol.Block;
+import org.apache.hadoop.hdfs.server.protocol.DatanodeStorage;
 import org.apache.hadoop.util.GSet;
 import org.apache.hadoop.util.LightWeightGSet;
 
+import com.google.common.base.Predicate;
+import com.google.common.collect.Iterables;
+
 /**
  * This class maintains the map from a block to its metadata.
  * block's metadata currently includes blockCollection it belongs to and
@@ -121,6 +125,22 @@ Iterable<DatanodeStorageInfo> getStorages(Block b) {
     return getStorages(blocks.get(b));
   }
 
+  /**
+   * Searches for the block in the BlocksMap and 
+   * returns {@link Iterable} of the storages the block belongs to
+   * <i>that are of the given {@link DatanodeStorage.State state}</i>.
+   * 
+   * @param state DatanodeStorage state by which to filter the returned Iterable
+   */
+  Iterable<DatanodeStorageInfo> getStorages(Block b, final DatanodeStorage.State state) {
+    return Iterables.filter(getStorages(blocks.get(b)), new Predicate<DatanodeStorageInfo>() {
+      @Override
+      public boolean apply(DatanodeStorageInfo storage) {
+        return storage.getState() == state;
+      }
+    });
+  }
+
   /**
    * For a block that has already been retrieved from the BlocksMap
    * returns {@link Iterable} of the storages the block belongs to.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NamenodeFsck.java

@@ -58,6 +58,8 @@
 import org.apache.hadoop.hdfs.protocol.SnapshottableDirectoryStatus;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockPlacementPolicy;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockPlacementStatus;
+import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeStorageInfo;
+import org.apache.hadoop.hdfs.server.blockmanagement.NumberReplicas;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants;
 import org.apache.hadoop.hdfs.server.datanode.CachingStrategy;
 import org.apache.hadoop.net.NetUtils;
@@ -378,11 +380,13 @@ void check(String parent, HdfsFileStatus file, Result res) throws IOException {
       boolean isCorrupt = lBlk.isCorrupt();
       String blkName = block.toString();
       DatanodeInfo[] locs = lBlk.getLocations();
-      res.totalReplicas += locs.length;
+      NumberReplicas numberReplicas = namenode.getNamesystem().getBlockManager().countNodes(block.getLocalBlock());
+      int liveReplicas = numberReplicas.liveReplicas();
+      res.totalReplicas += liveReplicas;
       short targetFileReplication = file.getReplication();
       res.numExpectedReplicas += targetFileReplication;
-      if (locs.length > targetFileReplication) {
+      if (liveReplicas > targetFileReplication) {
-        res.excessiveReplicas += (locs.length - targetFileReplication);
+        res.excessiveReplicas += (liveReplicas - targetFileReplication);
         res.numOverReplicatedBlocks += 1;
       }
       // Check if block is Corrupt
@@ -392,10 +396,10 @@ void check(String parent, HdfsFileStatus file, Result res) throws IOException {
         out.print("\n" + path + ": CORRUPT blockpool " + block.getBlockPoolId() + 
             " block " + block.getBlockName()+"\n");
       }
-      if (locs.length >= minReplication)
+      if (liveReplicas >= minReplication)
         res.numMinReplicatedBlocks++;
-      if (locs.length < targetFileReplication && locs.length > 0) {
+      if (liveReplicas < targetFileReplication && liveReplicas > 0) {
-        res.missingReplicas += (targetFileReplication - locs.length);
+        res.missingReplicas += (targetFileReplication - liveReplicas);
         res.numUnderReplicatedBlocks += 1;
         underReplicatedPerFile++;
         if (!showFiles) {
@@ -404,7 +408,7 @@ void check(String parent, HdfsFileStatus file, Result res) throws IOException {
         out.println(" Under replicated " + block +
                     ". Target Replicas is " +
                     targetFileReplication + " but found " +
-                    locs.length + " replica(s).");
+                    liveReplicas + " replica(s).");
       }
       // verify block placement policy
       BlockPlacementStatus blockPlacementStatus = bpPolicy
@@ -421,13 +425,13 @@ void check(String parent, HdfsFileStatus file, Result res) throws IOException {
                     block + ". " + blockPlacementStatus.getErrorDescription());
       }
       report.append(i + ". " + blkName + " len=" + block.getNumBytes());
-      if (locs.length == 0) {
+      if (liveReplicas == 0) {
         report.append(" MISSING!");
         res.addMissing(block.toString(), block.getNumBytes());
         missing++;
         missize += block.getNumBytes();
       } else {
-        report.append(" repl=" + locs.length);
+        report.append(" repl=" + liveReplicas);
         if (showLocations || showRacks) {
           StringBuilder sb = new StringBuilder("[");
           for (int j = 0; j < locs.length; j++) {

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

@@ -28,7 +28,18 @@ public class DatanodeStorage {
   /** The state of the storage. */
   public enum State {
     NORMAL,
-    READ_ONLY
+    
+    /**
+     * A storage that represents a read-only path to replicas stored on a shared storage device.
+     * Replicas on {@link #READ_ONLY_SHARED} storage are not counted towards live replicas.
+     * 
+     * <p>
+     * In certain implementations, a {@link #READ_ONLY_SHARED} storage may be correlated to 
+     * its {@link #NORMAL} counterpart using the {@link DatanodeStorage#storageID}.  This
+     * property should be used for debugging purposes only.
+     * </p> 
+     */
+    READ_ONLY_SHARED;
   }
   
   private final String storageID;

hadoop-hdfs-project/hadoop-hdfs/src/main/proto/DatanodeProtocol.proto

@@ -50,7 +50,7 @@ message DatanodeRegistrationProto {
 message DatanodeStorageProto {
   enum StorageState {
     NORMAL = 0;
-    READ_ONLY = 1;
+    READ_ONLY_SHARED = 1;
   }
 
   required string storageUuid = 1;

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

@@ -157,6 +157,7 @@ public static class Builder {
     private boolean checkExitOnShutdown = true;
     private boolean checkDataNodeAddrConfig = false;
     private boolean checkDataNodeHostConfig = false;
+    private Configuration[] dnConfOverlays;
     
     public Builder(Configuration conf) {
       this.conf = conf;
@@ -333,6 +334,19 @@ public Builder nnTopology(MiniDFSNNTopology topology) {
       return this;
     }
     
+    /**
+     * Default: null
+     * 
+     * An array of {@link Configuration} objects that will overlay the
+     * global MiniDFSCluster Configuration for the corresponding DataNode.
+     * 
+     * Useful for setting specific per-DataNode configuration parameters.
+     */
+    public Builder dataNodeConfOverlays(Configuration[] dnConfOverlays) {
+      this.dnConfOverlays = dnConfOverlays;
+      return this;
+    }
+    
     /**
      * Construct the actual MiniDFSCluster
      */
@@ -375,7 +389,8 @@ protected MiniDFSCluster(Builder builder) throws IOException {
                        builder.nnTopology,
                        builder.checkExitOnShutdown,
                        builder.checkDataNodeAddrConfig,
-                       builder.checkDataNodeHostConfig);
+                       builder.checkDataNodeHostConfig,
+                       builder.dnConfOverlays);
   }
   
   public class DataNodeProperties {
@@ -621,7 +636,7 @@ public MiniDFSCluster(int nameNodePort,
         manageNameDfsDirs, true, manageDataDfsDirs, manageDataDfsDirs, 
         operation, null, racks, hosts,
         simulatedCapacities, null, true, false,
-        MiniDFSNNTopology.simpleSingleNN(nameNodePort, 0), true, false, false);
+        MiniDFSNNTopology.simpleSingleNN(nameNodePort, 0), true, false, false, null);
   }
 
   private void initMiniDFSCluster(
@@ -634,7 +649,8 @@ private void initMiniDFSCluster(
       boolean waitSafeMode, boolean setupHostsFile,
       MiniDFSNNTopology nnTopology, boolean checkExitOnShutdown,
       boolean checkDataNodeAddrConfig,
-      boolean checkDataNodeHostConfig)
+      boolean checkDataNodeHostConfig,
+      Configuration[] dnConfOverlays)
   throws IOException {
     ExitUtil.disableSystemExit();
 
@@ -699,7 +715,7 @@ private void initMiniDFSCluster(
     startDataNodes(conf, numDataNodes, storageType, manageDataDfsDirs,
         dnStartOpt != null ? dnStartOpt : startOpt,
         racks, hosts, simulatedCapacities, setupHostsFile,
-        checkDataNodeAddrConfig, checkDataNodeHostConfig);
+        checkDataNodeAddrConfig, checkDataNodeHostConfig, dnConfOverlays);
     waitClusterUp();
     //make sure ProxyUsers uses the latest conf
     ProxyUsers.refreshSuperUserGroupsConfiguration(conf);
@@ -1102,7 +1118,7 @@ public synchronized void startDataNodes(Configuration conf, int numDataNodes,
                              long[] simulatedCapacities,
                              boolean setupHostsFile) throws IOException {
     startDataNodes(conf, numDataNodes, StorageType.DEFAULT, manageDfsDirs, operation, racks, hosts,
-        simulatedCapacities, setupHostsFile, false, false);
+        simulatedCapacities, setupHostsFile, false, false, null);
   }
 
   /**
@@ -1116,7 +1132,7 @@ public synchronized void startDataNodes(Configuration conf, int numDataNodes,
       boolean setupHostsFile,
       boolean checkDataNodeAddrConfig) throws IOException {
     startDataNodes(conf, numDataNodes, StorageType.DEFAULT, manageDfsDirs, operation, racks, hosts,
-        simulatedCapacities, setupHostsFile, checkDataNodeAddrConfig, false);
+        simulatedCapacities, setupHostsFile, checkDataNodeAddrConfig, false, null);
   }
 
   /**
@@ -1143,7 +1159,8 @@ public synchronized void startDataNodes(Configuration conf, int numDataNodes,
    * @param setupHostsFile add new nodes to dfs hosts files
    * @param checkDataNodeAddrConfig if true, only set DataNode port addresses if not already set in config
    * @param checkDataNodeHostConfig if true, only set DataNode hostname key if not already set in config
-   *
+   * @param dnConfOverlays An array of {@link Configuration} objects that will overlay the
+   *              global MiniDFSCluster Configuration for the corresponding DataNode.
    * @throws IllegalStateException if NameNode has been shutdown
    */
   public synchronized void startDataNodes(Configuration conf, int numDataNodes,
@@ -1152,7 +1169,8 @@ public synchronized void startDataNodes(Configuration conf, int numDataNodes,
       long[] simulatedCapacities,
       boolean setupHostsFile,
       boolean checkDataNodeAddrConfig,
-      boolean checkDataNodeHostConfig) throws IOException {
+      boolean checkDataNodeHostConfig,
+      Configuration[] dnConfOverlays) throws IOException {
     if (operation == StartupOption.RECOVER) {
       return;
     }
@@ -1193,6 +1211,13 @@ public synchronized void startDataNodes(Configuration conf, int numDataNodes,
           + "] is less than the number of datanodes [" + numDataNodes + "].");
     }
     
+    if (dnConfOverlays != null
+        && numDataNodes > dnConfOverlays.length) {
+      throw new IllegalArgumentException( "The length of dnConfOverlays [" 
+          + dnConfOverlays.length
+          + "] is less than the number of datanodes [" + numDataNodes + "].");
+    }
+
     String [] dnArgs = (operation == null ||
                         operation != StartupOption.ROLLBACK) ?
         null : new String[] {operation.getName()};
@@ -1200,6 +1225,9 @@ public synchronized void startDataNodes(Configuration conf, int numDataNodes,
     
     for (int i = curDatanodesNum; i < curDatanodesNum+numDataNodes; i++) {
       Configuration dnConf = new HdfsConfiguration(conf);
+      if (dnConfOverlays != null) {
+        dnConf.addResource(dnConfOverlays[i]);
+      }
       // Set up datanode address
       setupDatanodeAddress(dnConf, setupHostsFile, checkDataNodeAddrConfig);
       if (manageDfsDirs) {

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

@@ -210,7 +210,8 @@ public synchronized void startDataNodes(Configuration conf, int numDataNodes,
       long[] simulatedCapacities,
       boolean setupHostsFile,
       boolean checkDataNodeAddrConfig,
-      boolean checkDataNodeHostConfig) throws IOException {
+      boolean checkDataNodeHostConfig,
+      Configuration[] dnConfOverlays) throws IOException {
     startDataNodes(conf, numDataNodes, storageType, manageDfsDirs, operation, racks,
         NODE_GROUPS, hosts, simulatedCapacities, setupHostsFile, 
         checkDataNodeAddrConfig, checkDataNodeHostConfig);

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

@@ -34,6 +34,7 @@
 
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hdfs.DFSConfigKeys;
+import org.apache.hadoop.hdfs.StorageType;
 import org.apache.hadoop.hdfs.protocol.Block;
 import org.apache.hadoop.hdfs.protocol.BlockListAsLongs;
 import org.apache.hadoop.hdfs.protocol.BlockLocalPathInfo;
@@ -96,6 +97,11 @@ public static void setFactory(Configuration conf) {
   public static final long DEFAULT_CAPACITY = 2L<<40; // 1 terabyte
   public static final byte DEFAULT_DATABYTE = 9;
   
+  public static final String CONFIG_PROPERTY_STATE =
+      "dfs.datanode.simulateddatastorage.state";
+  private static final DatanodeStorage.State DEFAULT_STATE =
+      DatanodeStorage.State.NORMAL;
+  
   static final byte[] nullCrcFileData;
   static {
     DataChecksum checksum = DataChecksum.newDataChecksum(
@@ -325,9 +331,9 @@ void free(long amount) {
   private static class SimulatedStorage {
     private Map<String, SimulatedBPStorage> map = 
       new HashMap<String, SimulatedBPStorage>();
-    private final String storageUuid = "SimulatedStroage-" + DatanodeStorage.generateUuid();
 
     private final long capacity;  // in bytes
+    private final DatanodeStorage dnStorage;
     
     synchronized long getFree() {
       return capacity - getUsed();
@@ -365,8 +371,11 @@ synchronized void free(String bpid, long amount) throws IOException {
       getBPStorage(bpid).free(amount);
     }
     
-    SimulatedStorage(long cap) {
+    SimulatedStorage(long cap, DatanodeStorage.State state) {
       capacity = cap;
+      dnStorage = new DatanodeStorage(
+          "SimulatedStorage-" + DatanodeStorage.generateUuid(),
+          state, StorageType.DEFAULT);
     }
     
     synchronized void addBlockPool(String bpid) {
@@ -390,11 +399,15 @@ private SimulatedBPStorage getBPStorage(String bpid) throws IOException {
     }
 
     String getStorageUuid() {
-      return storageUuid;
+      return dnStorage.getStorageID();
+    }
+    
+    DatanodeStorage getDnStorage() {
+      return dnStorage;
     }
 
     synchronized StorageReport getStorageReport(String bpid) {
-      return new StorageReport(new DatanodeStorage(getStorageUuid()),
+      return new StorageReport(dnStorage,
           false, getCapacity(), getUsed(), getFree(),
           map.get(bpid).getUsed());
     }
@@ -417,7 +430,8 @@ public SimulatedFSDataset(DataStorage storage, Configuration conf) {
 
     registerMBean(datanodeUuid);
     this.storage = new SimulatedStorage(
-        conf.getLong(CONFIG_PROPERTY_CAPACITY, DEFAULT_CAPACITY));
+        conf.getLong(CONFIG_PROPERTY_CAPACITY, DEFAULT_CAPACITY),
+        conf.getEnum(CONFIG_PROPERTY_STATE, DEFAULT_STATE));
   }
 
   public synchronized void injectBlocks(String bpid,
@@ -488,7 +502,7 @@ synchronized BlockListAsLongs getBlockReport(String bpid) {
   @Override
   public synchronized Map<DatanodeStorage, BlockListAsLongs> getBlockReports(
       String bpid) {
-    return Collections.singletonMap(new DatanodeStorage(storage.storageUuid), getBlockReport(bpid));
+    return Collections.singletonMap(storage.getDnStorage(), getBlockReport(bpid));
   }
 
   @Override // FsDatasetSpi

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

@@ -0,0 +1,270 @@
+/**
+ * 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.datanode;
+
+import static org.hamcrest.CoreMatchers.*;
+import static org.junit.Assert.*;
+import static org.apache.hadoop.hdfs.server.protocol.DatanodeStorage.State.*;
+
+import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.util.Collections;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hdfs.DFSClient;
+import org.apache.hadoop.hdfs.DFSTestUtil;
+import org.apache.hadoop.hdfs.DistributedFileSystem;
+import org.apache.hadoop.hdfs.HdfsConfiguration;
+import org.apache.hadoop.hdfs.MiniDFSCluster;
+import org.apache.hadoop.hdfs.protocol.Block;
+import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
+import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
+import org.apache.hadoop.hdfs.protocol.LocatedBlock;
+import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
+import org.apache.hadoop.hdfs.server.blockmanagement.BlockManager;
+import org.apache.hadoop.hdfs.server.blockmanagement.BlockManagerTestUtil;
+import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeManager;
+import org.apache.hadoop.hdfs.server.blockmanagement.NumberReplicas;
+import org.apache.hadoop.hdfs.server.protocol.DatanodeStorage;
+import org.apache.hadoop.hdfs.server.protocol.StorageReport;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import com.google.common.collect.Iterables;
+
+/**
+ * Test proper {@link BlockManager} replication counting for {@link DatanodeStorage}s
+ * with {@link DatanodeStorage.State#READ_ONLY_SHARED READ_ONLY} state.
+ * 
+ * Uses {@link SimulatedFSDataset} to inject read-only replicas into a DataNode.
+ */
+public class TestReadOnlySharedStorage {
+
+  public static final Log LOG = LogFactory.getLog(TestReadOnlySharedStorage.class);
+
+  private static short NUM_DATANODES = 3;
+  private static int RO_NODE_INDEX = 0;
+  private static final int BLOCK_SIZE = 1024;
+  private static final long seed = 0x1BADF00DL;
+  private static final Path PATH = new Path("/" + TestReadOnlySharedStorage.class.getName() + ".dat");
+  private static final int RETRIES = 10;
+
+  private Configuration conf;
+  private MiniDFSCluster cluster;
+  private DistributedFileSystem fs;
+  private DFSClient client;
+
+  private BlockManager blockManager;
+
+  private DatanodeManager datanodeManager;
+  private DatanodeInfo normalDataNode;
+  private DatanodeInfo readOnlyDataNode;
+  
+  private Block block;
+
+  private ExtendedBlock extendedBlock;
+
+
+  /**
+   * Setup a {@link MiniDFSCluster}.
+   * Create a block with both {@link State#NORMAL} and {@link State#READ_ONLY_SHARED} replicas.
+   */
+  @Before
+  public void setup() throws IOException, InterruptedException {
+    conf = new HdfsConfiguration();
+    SimulatedFSDataset.setFactory(conf);
+    
+    Configuration[] overlays = new Configuration[NUM_DATANODES];
+    for (int i = 0; i < overlays.length; i++) {
+      overlays[i] = new Configuration();
+      if (i == RO_NODE_INDEX) {
+        overlays[i].setEnum(SimulatedFSDataset.CONFIG_PROPERTY_STATE, 
+            i == RO_NODE_INDEX 
+              ? READ_ONLY_SHARED
+              : NORMAL);
+      }
+    }
+    
+    cluster = new MiniDFSCluster.Builder(conf)
+        .numDataNodes(NUM_DATANODES)
+        .dataNodeConfOverlays(overlays)
+        .build();
+    fs = cluster.getFileSystem();
+    blockManager = cluster.getNameNode().getNamesystem().getBlockManager();
+    datanodeManager = blockManager.getDatanodeManager();
+    client = new DFSClient(new InetSocketAddress("localhost", cluster.getNameNodePort()),
+                           cluster.getConfiguration(0));
+    
+    for (int i = 0; i < NUM_DATANODES; i++) {
+      DataNode dataNode = cluster.getDataNodes().get(i);
+      validateStorageState(
+          BlockManagerTestUtil.getStorageReportsForDatanode(
+              datanodeManager.getDatanode(dataNode.getDatanodeId())),
+              i == RO_NODE_INDEX 
+                ? READ_ONLY_SHARED
+                : NORMAL);
+    }
+    
+    // Create a 1 block file
+    DFSTestUtil.createFile(fs, PATH, BLOCK_SIZE, BLOCK_SIZE,
+                           BLOCK_SIZE, (short) 1, seed);
+    
+    LocatedBlock locatedBlock = getLocatedBlock();
+    extendedBlock = locatedBlock.getBlock();
+    block = extendedBlock.getLocalBlock();
+    
+    assertThat(locatedBlock.getLocations().length, is(1));
+    normalDataNode = locatedBlock.getLocations()[0];
+    readOnlyDataNode = datanodeManager.getDatanode(cluster.getDataNodes().get(RO_NODE_INDEX).getDatanodeId());
+    assertThat(normalDataNode, is(not(readOnlyDataNode)));
+    
+    validateNumberReplicas(1);
+    
+    // Inject the block into the datanode with READ_ONLY_SHARED storage 
+    cluster.injectBlocks(RO_NODE_INDEX, Collections.singleton(block));
+    
+    // There should now be 2 *locations* for the block
+    // Must wait until the NameNode has processed the block report for the injected blocks
+    waitForLocations(2);
+  }
+  
+  @After
+  public void tearDown() throws IOException {
+    fs.delete(PATH, false);
+    
+    if (cluster != null) {
+      fs.close();
+      cluster.shutdown();
+      cluster = null;
+    }
+  }  
+  
+  private void waitForLocations(int locations) throws IOException, InterruptedException {
+    for (int tries = 0; tries < RETRIES; )
+      try {
+        LocatedBlock locatedBlock = getLocatedBlock();
+        assertThat(locatedBlock.getLocations().length, is(locations));
+        break;
+      } catch (AssertionError e) {
+        if (++tries < RETRIES) {
+          Thread.sleep(1000);
+        } else {
+          throw e;
+        }
+      }
+  }
+  
+  private LocatedBlock getLocatedBlock() throws IOException {
+    LocatedBlocks locatedBlocks = client.getLocatedBlocks(PATH.toString(), 0, BLOCK_SIZE);
+    assertThat(locatedBlocks.getLocatedBlocks().size(), is(1));
+    return Iterables.getOnlyElement(locatedBlocks.getLocatedBlocks());
+  }
+  
+  private void validateStorageState(StorageReport[] storageReports, DatanodeStorage.State state) {
+    for (StorageReport storageReport : storageReports) {
+      DatanodeStorage storage = storageReport.getStorage();
+      assertThat(storage.getState(), is(state));
+    }
+  }
+  
+  private void validateNumberReplicas(int expectedReplicas) throws IOException {
+    NumberReplicas numberReplicas = blockManager.countNodes(block);
+    assertThat(numberReplicas.liveReplicas(), is(expectedReplicas));
+    assertThat(numberReplicas.excessReplicas(), is(0));
+    assertThat(numberReplicas.corruptReplicas(), is(0));
+    assertThat(numberReplicas.decommissionedReplicas(), is(0));
+    assertThat(numberReplicas.replicasOnStaleNodes(), is(0));
+    
+    BlockManagerTestUtil.updateState(blockManager);
+    assertThat(blockManager.getUnderReplicatedBlocksCount(), is(0L));
+    assertThat(blockManager.getExcessBlocksCount(), is(0L));
+  }
+  
+  /**
+   * Verify that <tt>READ_ONLY_SHARED</tt> replicas are <i>not</i> counted towards the overall 
+   * replication count, but <i>are</i> included as replica locations returned to clients for reads.
+   */
+  @Test
+  public void testReplicaCounting() throws Exception {
+    // There should only be 1 *replica* (the READ_ONLY_SHARED doesn't count)
+    validateNumberReplicas(1);
+    
+    fs.setReplication(PATH, (short) 2);
+
+    // There should now be 3 *locations* for the block, and 2 *replicas*
+    waitForLocations(3);
+    validateNumberReplicas(2);
+  }
+
+  /**
+   * Verify that the NameNode is able to still use <tt>READ_ONLY_SHARED</tt> replicas even 
+   * when the single NORMAL replica is offline (and the effective replication count is 0).
+   */
+  @Test
+  public void testNormalReplicaOffline() throws Exception {
+    // Stop the datanode hosting the NORMAL replica
+    cluster.stopDataNode(normalDataNode.getXferAddr());
+    
+    // Force NameNode to detect that the datanode is down
+    BlockManagerTestUtil.noticeDeadDatanode(
+        cluster.getNameNode(), normalDataNode.getXferAddr());
+    
+    // The live replica count should now be zero (since the NORMAL replica is offline)
+    NumberReplicas numberReplicas = blockManager.countNodes(block);
+    assertThat(numberReplicas.liveReplicas(), is(0));
+    
+    // The block should be reported as under-replicated
+    BlockManagerTestUtil.updateState(blockManager);
+    assertThat(blockManager.getUnderReplicatedBlocksCount(), is(1L));
+    
+    // The BlockManager should be able to heal the replication count back to 1
+    // by triggering an inter-datanode replication from one of the READ_ONLY_SHARED replicas
+    BlockManagerTestUtil.computeAllPendingWork(blockManager);
+    
+    DFSTestUtil.waitForReplication(cluster, extendedBlock, 1, 1, 0);
+    
+    // There should now be 2 *locations* for the block, and 1 *replica*
+    assertThat(getLocatedBlock().getLocations().length, is(2));
+    validateNumberReplicas(1);
+  }
+  
+  /**
+   * Verify that corrupt <tt>READ_ONLY_SHARED</tt> replicas aren't counted 
+   * towards the corrupt replicas total.
+   */
+  @Test
+  public void testReadOnlyReplicaCorrupt() throws Exception {
+    // "Corrupt" a READ_ONLY_SHARED replica by reporting it as a bad replica
+    client.reportBadBlocks(new LocatedBlock[] { 
+        new LocatedBlock(extendedBlock, new DatanodeInfo[] { readOnlyDataNode })
+    });
+
+    // There should now be only 1 *location* for the block as the READ_ONLY_SHARED is corrupt
+    waitForLocations(1);
+    
+    // However, the corrupt READ_ONLY_SHARED replica should *not* affect the overall corrupt replicas count
+    NumberReplicas numberReplicas = blockManager.countNodes(block);
+    assertThat(numberReplicas.corruptReplicas(), is(0));
+  }
+
+}