HDFS-9837. BlockManager#countNodes should be able to detect duplicated internal blocks. Contributed by Jing Zhao.

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

@@ -435,6 +435,9 @@ Trunk (Unreleased)
     HDFS-9818. Correctly handle EC reconstruction work caused by not enough
     racks. (jing9)
 
+    HDFS-9837. BlockManager#countNodes should be able to detect duplicated
+    internal blocks. (jing9)
+
     BREAKDOWN OF HDFS-7285 SUBTASKS AND RELATED JIRAS
 
       HDFS-7347. Configurable erasure coding policy for individual files and

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

@@ -23,6 +23,9 @@ import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.BlockUCState;
 import org.apache.hadoop.hdfs.util.StripedBlockUtil;
 import org.apache.hadoop.hdfs.protocol.ErasureCodingPolicy;
 
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+
 /**
  * Subclass of {@link BlockInfo}, presenting a block group in erasure coding.
  *
@@ -227,4 +230,47 @@ public class BlockInfoStriped extends BlockInfo {
     }
     return true;
   }
+
+  static class StorageAndBlockIndex {
+    final DatanodeStorageInfo storage;
+    final byte blockIndex;
+
+    StorageAndBlockIndex(DatanodeStorageInfo storage, byte blockIndex) {
+      this.storage = storage;
+      this.blockIndex = blockIndex;
+    }
+  }
+
+  public Iterable<StorageAndBlockIndex> getStorageAndIndexInfos() {
+    return new Iterable<StorageAndBlockIndex>() {
+      @Override
+      public Iterator<StorageAndBlockIndex> iterator() {
+        return new Iterator<StorageAndBlockIndex>() {
+          private int index = 0;
+
+          @Override
+          public boolean hasNext() {
+            while (index < getCapacity() && getStorageInfo(index) == null) {
+              index++;
+            }
+            return index < getCapacity();
+          }
+
+          @Override
+          public StorageAndBlockIndex next() {
+            if (!hasNext()) {
+              throw new NoSuchElementException();
+            }
+            int i = index++;
+            return new StorageAndBlockIndex(storages[i], indices[i]);
+          }
+
+          @Override
+          public void remove() {
+            throw new UnsupportedOperationException("Remove is not supported");
+          }
+        };
+      }
+    };
+  }
 }

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

@@ -71,8 +71,10 @@ import org.apache.hadoop.hdfs.security.token.block.BlockTokenSecretManager;
 import org.apache.hadoop.hdfs.security.token.block.BlockTokenIdentifier.AccessMode;
 import org.apache.hadoop.hdfs.security.token.block.DataEncryptionKey;
 import org.apache.hadoop.hdfs.security.token.block.ExportedBlockKeys;
+import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoStriped.StorageAndBlockIndex;
 import org.apache.hadoop.hdfs.server.blockmanagement.CorruptReplicasMap.Reason;
 import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeStorageInfo.AddBlockResult;
+import org.apache.hadoop.hdfs.server.blockmanagement.NumberReplicas.StoredReplicaState;
 import org.apache.hadoop.hdfs.server.blockmanagement.PendingDataNodeMessages.ReportedBlockInfo;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.BlockUCState;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.ReplicaState;
@@ -1816,76 +1818,62 @@ public class BlockManager implements BlockStatsMXBean {
     containingNodes.clear();
     nodesContainingLiveReplicas.clear();
     List<DatanodeDescriptor> srcNodes = new ArrayList<>();
-    int live = 0;
-    int readonly = 0;
-    int decommissioned = 0;
-    int decommissioning = 0;
-    int corrupt = 0;
-    int excess = 0;
     liveBlockIndices.clear();
     final boolean isStriped = block.isStriped();
 
-    Collection<DatanodeDescriptor> nodesCorrupt = corruptReplicas.getNodes(block);
+    BitSet bitSet = isStriped ?
+        new BitSet(((BlockInfoStriped) block).getTotalBlockNum()) : null;
     for (DatanodeStorageInfo storage : blocksMap.getStorages(block)) {
       final DatanodeDescriptor node = storage.getDatanodeDescriptor();
-      LightWeightHashSet<BlockInfo> excessBlocks =
-        excessReplicateMap.get(node.getDatanodeUuid());
-      int countableReplica = storage.getState() == State.NORMAL ? 1 : 0;
-      if ((nodesCorrupt != null) && (nodesCorrupt.contains(node)))
-        corrupt += countableReplica;
-      else if (node.isDecommissionInProgress()) {
-        decommissioning += countableReplica;
-      } else if (node.isDecommissioned()) {
-        decommissioned += countableReplica;
-      } else if (excessBlocks != null && excessBlocks.contains(block)) {
-        excess += countableReplica;
-      } else {
+      final StoredReplicaState state = checkReplicaOnStorage(numReplicas, block,
+          storage, corruptReplicas.getNodes(block), false);
+      if (state == StoredReplicaState.LIVE) {
         nodesContainingLiveReplicas.add(storage);
-        live += countableReplica;
-      }
-      if (storage.getState() == State.READ_ONLY_SHARED) {
-        readonly++;
       }
       containingNodes.add(node);
-      // Check if this replica is corrupt
-      // If so, do not select the node as src node
-      if ((nodesCorrupt != null) && nodesCorrupt.contains(node))
+
+      // do not select corrupted replica as src. also do not select the block
+      // that is already in excess map
+      if (state == StoredReplicaState.CORRUPT ||
+          state == StoredReplicaState.EXCESS) {
         continue;
+      }
+
       if(priority != UnderReplicatedBlocks.QUEUE_HIGHEST_PRIORITY 
           && !node.isDecommissionInProgress() 
-          && node.getNumberOfBlocksToBeReplicated() >= maxReplicationStreams)
-      {
+          && node.getNumberOfBlocksToBeReplicated() >= maxReplicationStreams) {
         continue; // already reached replication limit
       }
-      if (node.getNumberOfBlocksToBeReplicated() >= replicationStreamsHardLimit)
-      {
+      if (node.getNumberOfBlocksToBeReplicated() >= replicationStreamsHardLimit) {
         continue;
       }
-      // the block must not be scheduled for removal on srcNode
-      if(excessBlocks != null && excessBlocks.contains(block))
-        continue;
       // never use already decommissioned nodes
-      if(node.isDecommissioned())
+      if (node.isDecommissioned()) {
         continue;
+      }
 
       if(isStriped || srcNodes.isEmpty()) {
         srcNodes.add(node);
         if (isStriped) {
-          liveBlockIndices.add(((BlockInfoStriped) block).
-              getStorageBlockIndex(storage));
+          byte blockIndex = ((BlockInfoStriped) block).
+              getStorageBlockIndex(storage);
+          liveBlockIndices.add(blockIndex);
+          if (!bitSet.get(blockIndex)) {
+            bitSet.set(blockIndex);
+          } else if (state == StoredReplicaState.LIVE) {
+            numReplicas.subtract(StoredReplicaState.LIVE, 1);
+            numReplicas.add(StoredReplicaState.REDUNDANT, 1);
+          }
         }
         continue;
       }
       // for replicated block, switch to a different node randomly
       // this to prevent from deterministically selecting the same node even
       // if the node failed to replicate the block on previous iterations
-      if (!isStriped && ThreadLocalRandom.current().nextBoolean()) {
+      if (ThreadLocalRandom.current().nextBoolean()) {
         srcNodes.set(0, node);
       }
     }
-    if(numReplicas != null)
-      numReplicas.set(live, readonly, decommissioned, decommissioning, corrupt,
-          excess, 0);
     return srcNodes.toArray(new DatanodeDescriptor[srcNodes.size()]);
   }
 
@@ -2872,8 +2860,8 @@ public class BlockManager implements BlockStatsMXBean {
     // Now check for completion of blocks and safe block count
     NumberReplicas num = countNodes(storedBlock);
     int numLiveReplicas = num.liveReplicas();
-    int numCurrentReplica = numLiveReplicas
-      + pendingReplications.getNumReplicas(storedBlock);
+    int pendingNum = pendingReplications.getNumReplicas(storedBlock);
+    int numCurrentReplica = numLiveReplicas + pendingNum;
 
     if(storedBlock.getBlockUCState() == BlockUCState.COMMITTED &&
         hasMinStorage(storedBlock, numLiveReplicas)) {
@@ -2907,7 +2895,7 @@ public class BlockManager implements BlockStatsMXBean {
     } else {
       updateNeededReplications(storedBlock, curReplicaDelta, 0);
     }
-    if (numCurrentReplica > fileReplication) {
+    if (shouldProcessOverReplicated(num, pendingNum, fileReplication)) {
       processOverReplicatedBlock(storedBlock, fileReplication, node, delNodeHint);
     }
     // If the file replication has reached desired value
@@ -2925,6 +2913,13 @@ public class BlockManager implements BlockStatsMXBean {
     return storedBlock;
   }
 
+  private boolean shouldProcessOverReplicated(NumberReplicas num,
+      int pendingNum, int expectedNum) {
+    int numCurrent = num.liveReplicas() + pendingNum;
+    return numCurrent > expectedNum ||
+        (numCurrent == expectedNum && num.redundantInternalBlocks() > 0);
+  }
+
   /**
    * Invalidate corrupt replicas.
    * <p>
@@ -3129,7 +3124,7 @@ public class BlockManager implements BlockStatsMXBean {
     // calculate current replication
     short expectedReplication = getExpectedReplicaNum(block);
     NumberReplicas num = countNodes(block);
-    int numCurrentReplica = num.liveReplicas();
+    final int numCurrentReplica = num.liveReplicas();
     // add to under-replicated queue if need to be
     if (isNeededReplication(block, numCurrentReplica)) {
       if (neededReplications.add(block, numCurrentReplica, num.readOnlyReplicas(),
@@ -3138,7 +3133,7 @@ public class BlockManager implements BlockStatsMXBean {
       }
     }
 
-    if (numCurrentReplica > expectedReplication) {
+    if (shouldProcessOverReplicated(num, 0, expectedReplication)) {
       if (num.replicasOnStaleNodes() > 0) {
         // If any of the replicas of this block are on nodes that are
         // considered "stale", then these replicas may in fact have
@@ -3666,46 +3661,94 @@ public class BlockManager implements BlockStatsMXBean {
    * Return the number of nodes hosting a given block, grouped
    * by the state of those replicas.
    * For a striped block, this includes nodes storing blocks belonging to the
-   * striped block group.
+   * striped block group. But note we exclude duplicated internal block replicas
+   * for calculating {@link NumberReplicas#liveReplicas}.
    */
-  public NumberReplicas countNodes(Block b) {
-    int decommissioned = 0;
-    int decommissioning = 0;
-    int live = 0;
-    int readonly = 0;
-    int corrupt = 0;
-    int excess = 0;
-    int stale = 0;
+  public NumberReplicas countNodes(BlockInfo b) {
+    return countNodes(b, false);
+  }
+
+  private NumberReplicas countNodes(BlockInfo b, boolean inStartupSafeMode) {
+    NumberReplicas numberReplicas = new NumberReplicas();
     Collection<DatanodeDescriptor> nodesCorrupt = corruptReplicas.getNodes(b);
-    for(DatanodeStorageInfo storage : blocksMap.getStorages(b)) {
-      if (storage.getState() == State.FAILED) {
-        continue;
-      } else if (storage.getState() == State.READ_ONLY_SHARED) {
-        readonly++;
-        continue;
-      }
-      final DatanodeDescriptor node = storage.getDatanodeDescriptor();
-      if ((nodesCorrupt != null) && (nodesCorrupt.contains(node))) {
-        corrupt++;
-      } else if (node.isDecommissionInProgress()) {
-        decommissioning++;
-      } else if (node.isDecommissioned()) {
-        decommissioned++;
-      } else {
-        LightWeightHashSet<BlockInfo> blocksExcess = excessReplicateMap.get(
-            node.getDatanodeUuid());
-        if (blocksExcess != null && blocksExcess.contains(b)) {
-          excess++;
-        } else {
-          live++;
-        }
-      }
-      if (storage.areBlockContentsStale()) {
-        stale++;
+    if (b.isStriped()) {
+      countReplicasForStripedBlock(numberReplicas, (BlockInfoStriped) b,
+          nodesCorrupt, inStartupSafeMode);
+    } else {
+      for (DatanodeStorageInfo storage : blocksMap.getStorages(b)) {
+        checkReplicaOnStorage(numberReplicas, b, storage, nodesCorrupt,
+            inStartupSafeMode);
       }
     }
-    return new NumberReplicas(live, readonly, decommissioned, decommissioning,
-        corrupt, excess, stale);
+    return numberReplicas;
+  }
+
+  private StoredReplicaState checkReplicaOnStorage(NumberReplicas counters,
+      BlockInfo b, DatanodeStorageInfo storage,
+      Collection<DatanodeDescriptor> nodesCorrupt, boolean inStartupSafeMode) {
+    final StoredReplicaState s;
+    if (storage.getState() == State.NORMAL) {
+      final DatanodeDescriptor node = storage.getDatanodeDescriptor();
+      if (nodesCorrupt != null && nodesCorrupt.contains(node)) {
+        s = StoredReplicaState.CORRUPT;
+      } else if (inStartupSafeMode) {
+        s = StoredReplicaState.LIVE;
+        counters.add(s, 1);
+        return s;
+      } else if (node.isDecommissionInProgress()) {
+        s = StoredReplicaState.DECOMMISSIONING;
+      } else if (node.isDecommissioned()) {
+        s = StoredReplicaState.DECOMMISSIONED;
+      } else if (isExcess(node, b)) {
+        s = StoredReplicaState.EXCESS;
+      } else {
+        s = StoredReplicaState.LIVE;
+      }
+      counters.add(s, 1);
+      if (storage.areBlockContentsStale()) {
+        counters.add(StoredReplicaState.STALESTORAGE, 1);
+      }
+    } else if (!inStartupSafeMode &&
+        storage.getState() == State.READ_ONLY_SHARED) {
+      s = StoredReplicaState.READONLY;
+      counters.add(s, 1);
+    } else {
+      s = null;
+    }
+    return s;
+  }
+
+  /**
+   * For a striped block, it is possible it contains full number of internal
+   * blocks (i.e., 9 by default), but with duplicated replicas of the same
+   * internal block. E.g., for the following list of internal blocks
+   * b0, b0, b1, b2, b3, b4, b5, b6, b7
+   * we have 9 internal blocks but we actually miss b8.
+   * We should use this method to detect the above scenario and schedule
+   * necessary reconstruction.
+   */
+  private void countReplicasForStripedBlock(NumberReplicas counters,
+      BlockInfoStriped block, Collection<DatanodeDescriptor> nodesCorrupt,
+      boolean inStartupSafeMode) {
+    BitSet bitSet = new BitSet(block.getTotalBlockNum());
+    for (StorageAndBlockIndex si : block.getStorageAndIndexInfos()) {
+      StoredReplicaState state = checkReplicaOnStorage(counters, block,
+          si.storage, nodesCorrupt, inStartupSafeMode);
+      if (state == StoredReplicaState.LIVE) {
+        if (!bitSet.get(si.blockIndex)) {
+          bitSet.set(si.blockIndex);
+        } else {
+          counters.subtract(StoredReplicaState.LIVE, 1);
+          counters.add(StoredReplicaState.REDUNDANT, 1);
+        }
+      }
+    }
+  }
+
+  private boolean isExcess(DatanodeDescriptor node, BlockInfo block) {
+    LightWeightHashSet<BlockInfo> blocksExcess = excessReplicateMap.get(
+        node.getDatanodeUuid());
+    return blocksExcess != null && blocksExcess.contains(block);
   }
 
   /** 
@@ -3719,21 +3762,8 @@ public class BlockManager implements BlockStatsMXBean {
    * @return count of live nodes for this block
    */
   int countLiveNodes(BlockInfo b) {
-    if (!namesystem.isInStartupSafeMode()) {
-      return countNodes(b).liveReplicas();
-    }
-    // else proceed with fast case
-    int live = 0;
-    Collection<DatanodeDescriptor> nodesCorrupt = corruptReplicas.getNodes(b);
-    for (DatanodeStorageInfo storage : blocksMap.getStorages(b)) {
-      if (storage.getState() != State.NORMAL) {
-        continue;
-      }
-      final DatanodeDescriptor node = storage.getDatanodeDescriptor();
-      if ((nodesCorrupt == null) || (!nodesCorrupt.contains(node)))
-        live++;
-    }
-    return live;
+    final boolean inStartupSafeMode = namesystem.isInStartupSafeMode();
+    return countNodes(b, inStartupSafeMode).liveReplicas();
   }
   
   /**
@@ -3752,8 +3782,7 @@ public class BlockManager implements BlockStatsMXBean {
       final BlockInfo block = it.next();
       int expectedReplication = this.getReplication(block);
       NumberReplicas num = countNodes(block);
-      int numCurrentReplica = num.liveReplicas();
-      if (numCurrentReplica > expectedReplication) {
+      if (shouldProcessOverReplicated(num, 0, expectedReplication)) {
         // over-replicated block
         processOverReplicatedBlock(block, (short) expectedReplication, null,
             null);
@@ -3890,7 +3919,7 @@ public class BlockManager implements BlockStatsMXBean {
         neededReplications.add(block, n.liveReplicas() + pending,
             n.readOnlyReplicas(),
             n.decommissionedAndDecommissioning(), expected);
-      } else if (n.liveReplicas() > expected) {
+      } else if (shouldProcessOverReplicated(n, 0, expected)) {
         processOverReplicatedBlock(block, expected, null, null);
       }
     }

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

@@ -17,59 +17,49 @@
  */
 package org.apache.hadoop.hdfs.server.blockmanagement;
 
+import org.apache.hadoop.hdfs.util.EnumCounters;
+
+import static org.apache.hadoop.hdfs.server.blockmanagement.NumberReplicas.StoredReplicaState.CORRUPT;
+import static org.apache.hadoop.hdfs.server.blockmanagement.NumberReplicas.StoredReplicaState.DECOMMISSIONED;
+import static org.apache.hadoop.hdfs.server.blockmanagement.NumberReplicas.StoredReplicaState.DECOMMISSIONING;
+import static org.apache.hadoop.hdfs.server.blockmanagement.NumberReplicas.StoredReplicaState.EXCESS;
+import static org.apache.hadoop.hdfs.server.blockmanagement.NumberReplicas.StoredReplicaState.LIVE;
+import static org.apache.hadoop.hdfs.server.blockmanagement.NumberReplicas.StoredReplicaState.REDUNDANT;
+import static org.apache.hadoop.hdfs.server.blockmanagement.NumberReplicas.StoredReplicaState.STALESTORAGE;
+import static org.apache.hadoop.hdfs.server.blockmanagement.NumberReplicas.StoredReplicaState.READONLY;
+
 /**
  * A immutable object that stores the number of live replicas and
  * the number of decommissioned Replicas.
  */
-public class NumberReplicas {
-  private int liveReplicas;
-  private int readOnlyReplicas;
+public class NumberReplicas extends EnumCounters<NumberReplicas.StoredReplicaState> {
 
-  // Tracks only the decommissioning replicas
-  private int decommissioning;
-  // Tracks only the decommissioned replicas
-  private int decommissioned;
-  private int corruptReplicas;
-  private int excessReplicas;
-  private int replicasOnStaleNodes;
-
-  NumberReplicas() {
-    this(0, 0, 0, 0, 0, 0, 0);
+  public enum StoredReplicaState {
+    // live replicas. for a striped block, this value excludes redundant
+    // replicas for the same internal block
+    LIVE,
+    READONLY,
+    DECOMMISSIONING,
+    DECOMMISSIONED,
+    CORRUPT,
+    // excess replicas already tracked by blockmanager's excess map
+    EXCESS,
+    STALESTORAGE,
+    // for striped blocks only. number of redundant internal block replicas
+    // that have not been tracked by blockmanager yet (i.e., not in excess)
+    REDUNDANT
   }
 
-  NumberReplicas(int live, int readonly, int decommissioned,
-      int decommissioning, int corrupt, int excess, int stale) {
-    set(live, readonly, decommissioned, decommissioning, corrupt, excess, stale);
-  }
-
-  void set(int live, int readonly, int decommissioned, int decommissioning,
-      int corrupt, int excess, int stale) {
-    liveReplicas = live;
-    readOnlyReplicas = readonly;
-    this.decommissioning = decommissioning;
-    this.decommissioned = decommissioned;
-    corruptReplicas = corrupt;
-    excessReplicas = excess;
-    replicasOnStaleNodes = stale;
+  public NumberReplicas() {
+    super(StoredReplicaState.class);
   }
 
   public int liveReplicas() {
-    return liveReplicas;
+    return (int) get(LIVE);
   }
 
   public int readOnlyReplicas() {
-    return readOnlyReplicas;
-  }
-
-  /**
-   *
-   * @return decommissioned replicas + decommissioning replicas
-   * It is deprecated by decommissionedAndDecommissioning
-   * due to its misleading name.
-   */
-  @Deprecated
-  public int decommissionedReplicas() {
-    return decommissionedAndDecommissioning();
+    return (int) get(READONLY);
   }
 
   /**
@@ -77,7 +67,7 @@ public class NumberReplicas {
    * @return decommissioned and decommissioning replicas
    */
   public int decommissionedAndDecommissioning() {
-    return decommissioned + decommissioning;
+    return (int) (get(DECOMMISSIONED) + get(DECOMMISSIONING));
   }
 
   /**
@@ -85,7 +75,7 @@ public class NumberReplicas {
    * @return decommissioned replicas only
    */
   public int decommissioned() {
-    return decommissioned;
+    return (int) get(DECOMMISSIONED);
   }
 
   /**
@@ -93,15 +83,15 @@ public class NumberReplicas {
    * @return decommissioning replicas only
    */
   public int decommissioning() {
-    return decommissioning;
+    return (int) get(DECOMMISSIONING);
   }
 
   public int corruptReplicas() {
-    return corruptReplicas;
+    return (int) get(CORRUPT);
   }
 
   public int excessReplicas() {
-    return excessReplicas;
+    return (int) get(EXCESS);
   }
   
   /**
@@ -110,6 +100,10 @@ public class NumberReplicas {
    * replica may count as both "live" and "stale".
    */
   public int replicasOnStaleNodes() {
-    return replicasOnStaleNodes;
+    return (int) get(STALESTORAGE);
+  }
+
+  public int redundantInternalBlocks() {
+    return (int) get(REDUNDANT);
   }
 } 

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

@@ -437,7 +437,7 @@ public class TestBlockManagerSafeMode {
     doReturn(storedBlock).when(bm).getStoredBlock(any(Block.class));
     NumberReplicas numberReplicas = mock(NumberReplicas.class);
     when(numberReplicas.liveReplicas()).thenReturn(0);
-    doReturn(numberReplicas).when(bm).countNodes(any(Block.class));
+    doReturn(numberReplicas).when(bm).countNodes(any(BlockInfo.class));
   }
 
   /**

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

@@ -33,6 +33,7 @@ import org.apache.hadoop.hdfs.server.blockmanagement.BlockManager;
 import org.apache.hadoop.hdfs.server.datanode.DataNode;
 import org.apache.hadoop.hdfs.server.datanode.SimulatedFSDataset;
 import org.junit.After;
+import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
@@ -40,9 +41,11 @@ import org.junit.rules.Timeout;
 
 import java.io.IOException;
 import java.util.Arrays;
+import java.util.BitSet;
 import java.util.List;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
 
 public class TestAddOverReplicatedStripedBlocks {
 
@@ -68,6 +71,7 @@ public class TestAddOverReplicatedStripedBlocks {
     // disable block recovery
     conf.setInt(DFSConfigKeys.DFS_NAMENODE_REPLICATION_MAX_STREAMS_KEY, 0);
     conf.setInt(DFSConfigKeys.DFS_NAMENODE_REPLICATION_INTERVAL_KEY, 1);
+    conf.setInt(DFSConfigKeys.DFS_HEARTBEAT_INTERVAL_KEY, 1);
     SimulatedFSDataset.setFactory(conf);
     cluster = new MiniDFSCluster.Builder(conf).numDataNodes(numDNs).build();
     cluster.waitActive();
@@ -201,26 +205,35 @@ public class TestAddOverReplicatedStripedBlocks {
     } finally {
       cluster.getNamesystem().writeUnlock();
     }
-    assertEquals(1, bm.countNodes(blockInfo).corruptReplicas());
+    assertEquals(1, bm.countNodes(bm.getStoredBlock(blockInfo))
+        .corruptReplicas());
 
     // let a internal block be over replicated with 2 redundant block.
     blk.setBlockId(groupId + 2);
     cluster.injectBlocks(numDNs - 3, Arrays.asList(blk), bpid);
     cluster.injectBlocks(numDNs - 2, Arrays.asList(blk), bpid);
 
-    // update blocksMap
-    cluster.triggerBlockReports();
-    // add to invalidates
-    cluster.triggerHeartbeats();
-    // datanode delete block
-    cluster.triggerHeartbeats();
     // update blocksMap
     cluster.triggerBlockReports();
 
-    // verify that all internal blocks exists
-    lbs = cluster.getNameNodeRpc().getBlockLocations(
-        filePath.toString(), 0, fileLen);
-    StripedFileTestUtil.verifyLocatedStripedBlocks(lbs, GROUP_SIZE);
+    // verify that all internal blocks exists except b0
+    // the redundant internal blocks will not be deleted before the corrupted
+    // block gets reconstructed. but since we set
+    // DFS_NAMENODE_REPLICATION_MAX_STREAMS_KEY to 0, the reconstruction will
+    // not happen
+    lbs = cluster.getNameNodeRpc().getBlockLocations(filePath.toString(), 0,
+        fileLen);
+    bg = (LocatedStripedBlock) (lbs.get(0));
+    assertEquals(GROUP_SIZE + 1, bg.getBlockIndices().length);
+    assertEquals(GROUP_SIZE + 1, bg.getLocations().length);
+    BitSet set = new BitSet(GROUP_SIZE);
+    for (byte index : bg.getBlockIndices()) {
+      set.set(index);
+    }
+    Assert.assertFalse(set.get(0));
+    for (int i = 1; i < GROUP_SIZE; i++) {
+      assertTrue(set.get(i));
+    }
   }
 
   @Test
@@ -260,11 +273,21 @@ public class TestAddOverReplicatedStripedBlocks {
     // update blocksMap
     cluster.triggerBlockReports();
 
-    // Since one block is missing, when over-replicated blocks got deleted,
-    // we are left GROUP_SIZE - 1 blocks.
-    lbs = cluster.getNameNodeRpc().getBlockLocations(
-        filePath.toString(), 0, fileLen);
-    StripedFileTestUtil.verifyLocatedStripedBlocks(lbs, GROUP_SIZE - 1);
+    // Since one block is missing, then over-replicated blocks will not be
+    // deleted until reconstruction happens
+    lbs = cluster.getNameNodeRpc().getBlockLocations(filePath.toString(), 0,
+        fileLen);
+    bg = (LocatedStripedBlock) (lbs.get(0));
+    assertEquals(GROUP_SIZE + 1, bg.getBlockIndices().length);
+    assertEquals(GROUP_SIZE + 1, bg.getLocations().length);
+    BitSet set = new BitSet(GROUP_SIZE);
+    for (byte index : bg.getBlockIndices()) {
+      set.set(index);
+    }
+    Assert.assertFalse(set.get(GROUP_SIZE - 1));
+    for (int i = 0; i < GROUP_SIZE - 1; i++) {
+      assertTrue(set.get(i));
+    }
   }
 
 }

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

@@ -28,6 +28,7 @@ import org.apache.hadoop.hdfs.StripedFileTestUtil;
 import org.apache.hadoop.hdfs.protocol.Block;
 import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
 import org.apache.hadoop.hdfs.protocol.LocatedBlock;
+import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
 import org.apache.hadoop.hdfs.protocol.LocatedStripedBlock;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfo;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoStriped;
@@ -36,11 +37,18 @@ import org.apache.hadoop.hdfs.server.blockmanagement.BlockManagerTestUtil;
 import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeDescriptor;
 import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeManager;
 import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeStorageInfo;
+import org.apache.hadoop.hdfs.server.blockmanagement.NumberReplicas;
 import org.apache.hadoop.hdfs.server.datanode.DataNode;
+import org.apache.hadoop.hdfs.server.datanode.DataNodeTestUtils;
 import org.apache.hadoop.hdfs.server.protocol.BlockECReconstructionCommand.BlockECReconstructionInfo;
 
 import org.apache.hadoop.hdfs.util.StripedBlockUtil;
+import org.junit.Assert;
 import org.junit.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.BitSet;
 import java.util.List;
 
 import static org.apache.hadoop.hdfs.StripedFileTestUtil.BLOCK_STRIPED_CELL_SIZE;
@@ -51,6 +59,8 @@ import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 
 public class TestReconstructStripedBlocks {
+  public static final Logger LOG = LoggerFactory.getLogger(
+      TestReconstructStripedBlocks.class);
   private static final int cellSize = StripedFileTestUtil.BLOCK_STRIPED_CELL_SIZE;
   private final short GROUP_SIZE =
       (short) (NUM_DATA_BLOCKS + NUM_PARITY_BLOCKS);
@@ -233,4 +243,97 @@ public class TestReconstructStripedBlocks {
     }
     return count;
   }
+
+  /**
+   * make sure the NN can detect the scenario where there are enough number of
+   * internal blocks (>=9 by default) but there is still missing data/parity
+   * block.
+   */
+  @Test
+  public void testCountLiveReplicas() throws Exception {
+    final HdfsConfiguration conf = new HdfsConfiguration();
+    conf.setInt(DFSConfigKeys.DFS_NAMENODE_REPLICATION_INTERVAL_KEY, 1);
+    conf.setBoolean(DFSConfigKeys.DFS_NAMENODE_REPLICATION_CONSIDERLOAD_KEY,
+        false);
+    cluster = new MiniDFSCluster.Builder(conf).numDataNodes(GROUP_SIZE + 2)
+        .build();
+    cluster.waitActive();
+    DistributedFileSystem fs = cluster.getFileSystem();
+
+    try {
+      fs.mkdirs(dirPath);
+      fs.setErasureCodingPolicy(dirPath, null);
+      DFSTestUtil.createFile(fs, filePath,
+          BLOCK_STRIPED_CELL_SIZE * NUM_DATA_BLOCKS * 2, (short) 1, 0L);
+
+      // stop a dn
+      LocatedBlocks blks = fs.getClient().getLocatedBlocks(filePath.toString(), 0);
+      LocatedStripedBlock block = (LocatedStripedBlock) blks.getLastLocatedBlock();
+      DatanodeInfo dnToStop = block.getLocations()[0];
+      MiniDFSCluster.DataNodeProperties dnProp =
+          cluster.stopDataNode(dnToStop.getXferAddr());
+      cluster.setDataNodeDead(dnToStop);
+
+      // wait for reconstruction to happen
+      DFSTestUtil.waitForReplication(fs, filePath, GROUP_SIZE, 15 * 1000);
+
+      // bring the dn back: 10 internal blocks now
+      cluster.restartDataNode(dnProp);
+      cluster.waitActive();
+
+      // stop another dn: 9 internal blocks, but only cover 8 real one
+      dnToStop = block.getLocations()[1];
+      cluster.stopDataNode(dnToStop.getXferAddr());
+      cluster.setDataNodeDead(dnToStop);
+
+      // currently namenode is able to track the missing block. but restart NN
+      cluster.restartNameNode(true);
+
+      for (DataNode dn : cluster.getDataNodes()) {
+        DataNodeTestUtils.triggerBlockReport(dn);
+      }
+
+      FSNamesystem fsn = cluster.getNamesystem();
+      BlockManager bm = fsn.getBlockManager();
+
+      Thread.sleep(3000); // wait 3 running cycles of replication monitor
+      for (DataNode dn : cluster.getDataNodes()) {
+        DataNodeTestUtils.triggerHeartbeat(dn);
+      }
+
+      // check if NN can detect the missing internal block and finish the
+      // reconstruction
+      boolean reconstructed = false;
+      for (int i = 0; i < 5; i++) {
+        NumberReplicas num = null;
+        fsn.readLock();
+        try {
+          BlockInfo blockInfo = cluster.getNamesystem().getFSDirectory()
+              .getINode4Write(filePath.toString()).asFile().getLastBlock();
+          num = bm.countNodes(blockInfo);
+        } finally {
+          fsn.readUnlock();
+        }
+        if (num.liveReplicas() >= GROUP_SIZE) {
+          reconstructed = true;
+          break;
+        } else {
+          Thread.sleep(1000);
+        }
+      }
+      Assert.assertTrue(reconstructed);
+
+      blks = fs.getClient().getLocatedBlocks(filePath.toString(), 0);
+      block = (LocatedStripedBlock) blks.getLastLocatedBlock();
+      BitSet bitSet = new BitSet(GROUP_SIZE);
+      for (byte index : block.getBlockIndices()) {
+        bitSet.set(index);
+      }
+      for (int i = 0; i < GROUP_SIZE; i++) {
+        Assert.assertTrue(bitSet.get(i));
+      }
+    } finally {
+      cluster.shutdown();
+    }
+  }
 }