HDFS-13671. Namenode deletes large dir slowly caused by FoldedTreeSet#removeAndGet (#3065)

Author: hust-hhb

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

@@ -291,18 +291,6 @@ public class DFSConfigKeys extends CommonConfigurationKeys {
   public static final int     DFS_NAMENODE_REPLICATION_MAX_STREAMS_DEFAULT = 2;
   public static final String  DFS_NAMENODE_REPLICATION_STREAMS_HARD_LIMIT_KEY = "dfs.namenode.replication.max-streams-hard-limit";
   public static final int     DFS_NAMENODE_REPLICATION_STREAMS_HARD_LIMIT_DEFAULT = 4;
-  public static final String DFS_NAMENODE_STORAGEINFO_DEFRAGMENT_INTERVAL_MS_KEY
-      = "dfs.namenode.storageinfo.defragment.interval.ms";
-  public static final int
-      DFS_NAMENODE_STORAGEINFO_DEFRAGMENT_INTERVAL_MS_DEFAULT = 10 * 60 * 1000;
-  public static final String DFS_NAMENODE_STORAGEINFO_DEFRAGMENT_TIMEOUT_MS_KEY
-      = "dfs.namenode.storageinfo.defragment.timeout.ms";
-  public static final int
-      DFS_NAMENODE_STORAGEINFO_DEFRAGMENT_TIMEOUT_MS_DEFAULT = 4;
-  public static final String DFS_NAMENODE_STORAGEINFO_DEFRAGMENT_RATIO_KEY
-      = "dfs.namenode.storageinfo.defragment.ratio";
-  public static final double
-      DFS_NAMENODE_STORAGEINFO_DEFRAGMENT_RATIO_DEFAULT = 0.75;
   public static final String DFS_NAMENODE_BLOCKREPORT_QUEUE_SIZE_KEY
       = "dfs.namenode.blockreport.queue.size";
   public static final int    DFS_NAMENODE_BLOCKREPORT_QUEUE_SIZE_DEFAULT

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

@@ -967,8 +967,8 @@ public static JournalInfoProto convert(JournalInfo j) {
 
 
   public static BlockReportContext convert(BlockReportContextProto proto) {
-    return new BlockReportContext(proto.getTotalRpcs(), proto.getCurRpc(),
-        proto.getId(), proto.getLeaseId(), proto.getSorted());
+    return new BlockReportContext(proto.getTotalRpcs(),
+        proto.getCurRpc(), proto.getId(), proto.getLeaseId());
   }
 
   public static BlockReportContextProto convert(BlockReportContext context) {
@@ -977,7 +977,6 @@ public static BlockReportContextProto convert(BlockReportContext context) {
         setCurRpc(context.getCurRpc()).
         setId(context.getReportId()).
         setLeaseId(context.getLeaseId()).
-        setSorted(context.isSorted()).
         build();
   }
 

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

@@ -19,8 +19,8 @@
 
 import java.io.IOException;
 import java.util.Iterator;
+import java.util.LinkedList;
 import java.util.List;
-import java.util.NoSuchElementException;
 
 import org.apache.hadoop.thirdparty.com.google.common.base.Preconditions;
 import org.apache.hadoop.classification.InterfaceAudience;
@@ -57,9 +57,19 @@ public abstract class BlockInfo extends Block
   /** For implementing {@link LightWeightGSet.LinkedElement} interface. */
   private LightWeightGSet.LinkedElement nextLinkedElement;
 
-
-  // Storages this block is replicated on
-  protected DatanodeStorageInfo[] storages;
+  /**
+   * This array contains triplets of references. For each i-th storage, the
+   * block belongs to triplets[3*i] is the reference to the
+   * {@link DatanodeStorageInfo} and triplets[3*i+1] and triplets[3*i+2] are
+   * references to the previous and the next blocks, respectively, in the list
+   * of blocks belonging to this storage.
+   *
+   * Using previous and next in Object triplets is done instead of a
+   * {@link LinkedList} list to efficiently use memory. With LinkedList the cost
+   * per replica is 42 bytes (LinkedList#Entry object per replica) versus 16
+   * bytes using the triplets.
+   */
+  protected Object[] triplets;
 
   private BlockUnderConstructionFeature uc;
 
@@ -69,14 +79,14 @@ public abstract class BlockInfo extends Block
    *             in the block group
    */
   public BlockInfo(short size) {
-    this.storages = new DatanodeStorageInfo[size];
+    this.triplets = new Object[3 * size];
     this.bcId = INVALID_INODE_ID;
     this.replication = isStriped() ? 0 : size;
   }
 
   public BlockInfo(Block blk, short size) {
     super(blk);
-    this.storages = new DatanodeStorageInfo[size];
+    this.triplets = new Object[3*size];
     this.bcId = INVALID_INODE_ID;
     this.replication = isStriped() ? 0 : size;
   }
@@ -106,31 +116,7 @@ public boolean isDeleted() {
   }
 
   public Iterator<DatanodeStorageInfo> getStorageInfos() {
-    return new Iterator<DatanodeStorageInfo>() {
-
-      private int index = 0;
-
-      @Override
-      public boolean hasNext() {
-        while (index < storages.length && storages[index] == null) {
-          index++;
-        }
-        return index < storages.length;
-      }
-
-      @Override
-      public DatanodeStorageInfo next() {
-        if (!hasNext()) {
-          throw new NoSuchElementException();
-        }
-        return storages[index++];
-      }
-
-      @Override
-      public void remove() {
-        throw new UnsupportedOperationException("Sorry. can't remove.");
-      }
-    };
+    return new BlocksMap.StorageIterator(this);
   }
 
   public DatanodeDescriptor getDatanode(int index) {
@@ -139,18 +125,73 @@ public DatanodeDescriptor getDatanode(int index) {
   }
 
   DatanodeStorageInfo getStorageInfo(int index) {
-    assert this.storages != null : "BlockInfo is not initialized";
-    return storages[index];
+    assert this.triplets != null : "BlockInfo is not initialized";
+    assert index >= 0 && index*3 < triplets.length : "Index is out of bound";
+    return (DatanodeStorageInfo)triplets[index*3];
+  }
+
+  BlockInfo getPrevious(int index) {
+    assert this.triplets != null : "BlockInfo is not initialized";
+    assert index >= 0 && index*3+1 < triplets.length : "Index is out of bound";
+    BlockInfo info = (BlockInfo)triplets[index*3+1];
+    assert info == null ||
+        info.getClass().getName().startsWith(BlockInfo.class.getName()) :
+        "BlockInfo is expected at " + index*3;
+    return info;
+  }
+
+  BlockInfo getNext(int index) {
+    assert this.triplets != null : "BlockInfo is not initialized";
+    assert index >= 0 && index*3+2 < triplets.length : "Index is out of bound";
+    BlockInfo info = (BlockInfo)triplets[index*3+2];
+    assert info == null || info.getClass().getName().startsWith(
+        BlockInfo.class.getName()) :
+        "BlockInfo is expected at " + index*3;
+    return info;
   }
 
   void setStorageInfo(int index, DatanodeStorageInfo storage) {
-    assert this.storages != null : "BlockInfo is not initialized";
-    this.storages[index] = storage;
+    assert this.triplets != null : "BlockInfo is not initialized";
+    assert index >= 0 && index*3 < triplets.length : "Index is out of bound";
+    triplets[index*3] = storage;
+  }
+
+  /**
+   * Return the previous block on the block list for the datanode at
+   * position index. Set the previous block on the list to "to".
+   *
+   * @param index - the datanode index
+   * @param to - block to be set to previous on the list of blocks
+   * @return current previous block on the list of blocks
+   */
+  BlockInfo setPrevious(int index, BlockInfo to) {
+    assert this.triplets != null : "BlockInfo is not initialized";
+    assert index >= 0 && index*3+1 < triplets.length : "Index is out of bound";
+    BlockInfo info = (BlockInfo) triplets[index*3+1];
+    triplets[index*3+1] = to;
+    return info;
+  }
+
+  /**
+   * Return the next block on the block list for the datanode at
+   * position index. Set the next block on the list to "to".
+   *
+   * @param index - the datanode index
+   * @param to - block to be set to next on the list of blocks
+   * @return current next block on the list of blocks
+   */
+  BlockInfo setNext(int index, BlockInfo to) {
+    assert this.triplets != null : "BlockInfo is not initialized";
+    assert index >= 0 && index*3+2 < triplets.length : "Index is out of bound";
+    BlockInfo info = (BlockInfo) triplets[index*3+2];
+    triplets[index*3+2] = to;
+    return info;
   }
 
   public int getCapacity() {
-    assert this.storages != null : "BlockInfo is not initialized";
-    return storages.length;
+    assert this.triplets != null : "BlockInfo is not initialized";
+    assert triplets.length % 3 == 0 : "Malformed BlockInfo";
+    return triplets.length / 3;
   }
 
   /**
@@ -227,6 +268,80 @@ int findStorageInfo(DatanodeStorageInfo storageInfo) {
     return -1;
   }
 
+  /**
+   * Insert this block into the head of the list of blocks
+   * related to the specified DatanodeStorageInfo.
+   * If the head is null then form a new list.
+   * @return current block as the new head of the list.
+   */
+  BlockInfo listInsert(BlockInfo head, DatanodeStorageInfo storage) {
+    int dnIndex = this.findStorageInfo(storage);
+    assert dnIndex >= 0 : "Data node is not found: current";
+    assert getPrevious(dnIndex) == null && getNext(dnIndex) == null :
+        "Block is already in the list and cannot be inserted.";
+    this.setPrevious(dnIndex, null);
+    this.setNext(dnIndex, head);
+    if (head != null) {
+      head.setPrevious(head.findStorageInfo(storage), this);
+    }
+    return this;
+  }
+
+  /**
+   * Remove this block from the list of blocks
+   * related to the specified DatanodeStorageInfo.
+   * If this block is the head of the list then return the next block as
+   * the new head.
+   * @return the new head of the list or null if the list becomes
+   * empy after deletion.
+   */
+  BlockInfo listRemove(BlockInfo head, DatanodeStorageInfo storage) {
+    if (head == null) {
+      return null;
+    }
+    int dnIndex = this.findStorageInfo(storage);
+    if (dnIndex < 0) { // this block is not on the data-node list
+      return head;
+    }
+
+    BlockInfo next = this.getNext(dnIndex);
+    BlockInfo prev = this.getPrevious(dnIndex);
+    this.setNext(dnIndex, null);
+    this.setPrevious(dnIndex, null);
+    if (prev != null) {
+      prev.setNext(prev.findStorageInfo(storage), next);
+    }
+    if (next != null) {
+      next.setPrevious(next.findStorageInfo(storage), prev);
+    }
+    if (this == head) { // removing the head
+      head = next;
+    }
+    return head;
+  }
+
+  /**
+   * Remove this block from the list of blocks related to the specified
+   * DatanodeDescriptor. Insert it into the head of the list of blocks.
+   *
+   * @return the new head of the list.
+   */
+  public BlockInfo moveBlockToHead(BlockInfo head, DatanodeStorageInfo storage,
+      int curIndex, int headIndex) {
+    if (head == this) {
+      return this;
+    }
+    BlockInfo next = this.setNext(curIndex, head);
+    BlockInfo prev = this.setPrevious(curIndex, null);
+
+    head.setPrevious(headIndex, this);
+    prev.setNext(prev.findStorageInfo(storage), next);
+    if (next != null) {
+      next.setPrevious(next.findStorageInfo(storage), prev);
+    }
+    return this;
+  }
+
   @Override
   public int hashCode() {
     // Super implementation is sufficient

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

@@ -38,20 +38,20 @@ public BlockInfoContiguous(Block blk, short size) {
   }
 
   /**
-   * Ensure that there is enough  space to include num more storages.
-   * @return first free storage index.
+   * Ensure that there is enough  space to include num more triplets.
+   * @return first free triplet index.
    */
   private int ensureCapacity(int num) {
-    assert this.storages != null : "BlockInfo is not initialized";
+    assert this.triplets != null : "BlockInfo is not initialized";
     int last = numNodes();
-    if (storages.length >= (last+num)) {
+    if (triplets.length >= (last+num)*3) {
       return last;
     }
     /* Not enough space left. Create a new array. Should normally
      * happen only when replication is manually increased by the user. */
-    DatanodeStorageInfo[] old = storages;
-    storages = new DatanodeStorageInfo[(last+num)];
-    System.arraycopy(old, 0, storages, 0, last);
+    Object[] old = triplets;
+    triplets = new Object[(last+num)*3];
+    System.arraycopy(old, 0, triplets, 0, last * 3);
     return last;
   }
 
@@ -63,6 +63,8 @@ boolean addStorage(DatanodeStorageInfo storage, Block reportedBlock) {
     // find the last null node
     int lastNode = ensureCapacity(1);
     setStorageInfo(lastNode, storage);
+    setNext(lastNode, null);
+    setPrevious(lastNode, null);
     return true;
   }
 
@@ -72,12 +74,18 @@ boolean removeStorage(DatanodeStorageInfo storage) {
     if (dnIndex < 0) { // the node is not found
       return false;
     }
+    assert getPrevious(dnIndex) == null && getNext(dnIndex) == null :
+        "Block is still in the list and must be removed first.";
     // find the last not null node
     int lastNode = numNodes()-1;
-    // replace current node entry by the lastNode one
+    // replace current node triplet by the lastNode one
     setStorageInfo(dnIndex, getStorageInfo(lastNode));
-    // set the last entry to null
+    setNext(dnIndex, getNext(lastNode));
+    setPrevious(dnIndex, getPrevious(lastNode));
+    // set the last triplet to null
     setStorageInfo(lastNode, null);
+    setNext(lastNode, null);
+    setPrevious(lastNode, null);
     return true;
   }
 
@@ -96,7 +104,8 @@ boolean isProvided() {
 
   @Override
   public int numNodes() {
-    assert this.storages != null : "BlockInfo is not initialized";
+    assert this.triplets != null : "BlockInfo is not initialized";
+    assert triplets.length % 3 == 0 : "Malformed BlockInfo";
 
     for (int idx = getCapacity()-1; idx >= 0; idx--) {
       if (getDatanode(idx) != null) {