remove ModDataSetSubLockStrategy, add DataNodeLayoutSubLockStrategy

Author: hfutatzhanghb

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

@@ -1744,10 +1744,6 @@ public class DFSConfigKeys extends CommonConfigurationKeys {
   public static final boolean
       DFS_DATANODE_LOCKMANAGER_TRACE_DEFAULT = false;
 
-  public static final String DFS_DATANODE_DATASET_SUBLOCK_COUNT_KEY =
-      "dfs.datanode.dataset.sublock.count";
-  public static final long DFS_DATANODE_DATASET_SUBLOCK_COUNT_DEFAULT = 1000L;
-
   // dfs.client.retry confs are moved to HdfsClientConfigKeys.Retry
   @Deprecated
   public static final String  DFS_CLIENT_RETRY_POLICY_ENABLED_KEY

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/ModDataSetSubLockStrategy.java renamed to hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNodeLayoutSubLockStrategy.java

@@ -18,36 +18,16 @@
 
 package org.apache.hadoop.hdfs.server.datanode;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-import java.util.ArrayList;
 import java.util.List;
 
-public class ModDataSetSubLockStrategy implements DataSetSubLockStrategy {
-  public static final Logger LOG = LoggerFactory.getLogger(DataSetSubLockStrategy.class);
-
-  private static final String LOCK_NAME_PERFIX = "SubLock";
-  private long modFactor;
-
-  public ModDataSetSubLockStrategy(long mod) {
-    if (mod <= 0) {
-      mod = 1L;
-    }
-    this.modFactor = mod;
-  }
-
+public class DataNodeLayoutSubLockStrategy implements DataSetSubLockStrategy {
   @Override
   public String blockIdToSubLock(long blockid) {
-    return LOCK_NAME_PERFIX + (blockid % modFactor);
+    return DatanodeUtil.idToBlockDirSuffixName(blockid);
   }
 
   @Override
   public List<String> getAllSubLockName() {
-    List<String> res = new ArrayList<>();
-    for (long i = 0L; i < modFactor; i++) {
-      res.add(LOCK_NAME_PERFIX + i);
-    }
-    return res;
+    return DatanodeUtil.getAllSubDirNameForDataSetLock();
   }
 }

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

@@ -21,6 +21,8 @@
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
 
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.hdfs.protocol.Block;
@@ -115,6 +117,8 @@ public static boolean dirNoFilesRecursive(
   /**
    * Get the directory where a finalized block with this ID should be stored.
    * Do not attempt to create the directory.
+   * Note: update {@link DatanodeUtil#idToBlockDirSuffixName(long)} and
+   * {@link DatanodeUtil#getAllSubDirNameForDataSetLock()} when current method changed.
    * @param root the root directory where finalized blocks are stored
    * @param blockId
    * @return
@@ -127,6 +131,30 @@ public static File idToBlockDir(File root, long blockId) {
     return new File(root, path);
   }
 
+  /**
+   * Take an example: we hava a block with blockid mapping to:
+   * "/data1/hadoop/hdfs/datanode/current/BP-xxxx/current/finalized/subdir0/subdir0"
+   * We return "subdir0/subdir0"
+   * @return
+   */
+  public static String idToBlockDirSuffixName(long blockId) {
+    int d1 = (int) ((blockId >> 16) & 0x1F);
+    int d2 = (int) ((blockId >> 8) & 0x1F);
+    return DataStorage.BLOCK_SUBDIR_PREFIX + d1 + SEP +
+        DataStorage.BLOCK_SUBDIR_PREFIX + d2;
+  }
+
+  public static List<String> getAllSubDirNameForDataSetLock() {
+    List<String> res = new ArrayList<>();
+    for (int d1 = 0; d1 <= 0x1F; d1++) {
+      for (int d2 = 0; d2 <= 0x1F; d2++) {
+        res.add(DataStorage.BLOCK_SUBDIR_PREFIX + d1 + SEP +
+            DataStorage.BLOCK_SUBDIR_PREFIX + d2);
+      }
+    }
+    return res;
+  }
+
   /**
    * @return the FileInputStream for the meta data of the given block.
    * @throws FileNotFoundException

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

@@ -64,12 +64,12 @@
 import org.apache.hadoop.hdfs.server.common.DataNodeLockManager;
 import org.apache.hadoop.hdfs.server.common.DataNodeLockManager.LockLevel;
 import org.apache.hadoop.hdfs.server.datanode.DataNodeFaultInjector;
+import org.apache.hadoop.hdfs.server.datanode.DataNodeLayoutSubLockStrategy;
 import org.apache.hadoop.hdfs.server.datanode.DataSetLockManager;
 import org.apache.hadoop.hdfs.server.datanode.DataSetSubLockStrategy;
 import org.apache.hadoop.hdfs.server.datanode.FileIoProvider;
 import org.apache.hadoop.hdfs.server.datanode.FinalizedReplica;
 import org.apache.hadoop.hdfs.server.datanode.LocalReplica;
-import org.apache.hadoop.hdfs.server.datanode.ModDataSetSubLockStrategy;
 import org.apache.hadoop.hdfs.server.datanode.metrics.DataNodeMetrics;
 import org.apache.hadoop.util.AutoCloseableLock;
 import org.apache.hadoop.hdfs.protocol.Block;
@@ -292,7 +292,6 @@ public LengthInputStream getMetaDataInputStream(ExtendedBlock b)
   private volatile long lastDirScannerFinishTime;
 
   private final DataSetSubLockStrategy datasetSubLockStrategy;
-  private final long datasetSubLockCount;
 
   /**
    * An FSDataset has a directory where it loads its data files.
@@ -398,9 +397,7 @@ public LengthInputStream getMetaDataInputStream(ExtendedBlock b)
         DFSConfigKeys.DFS_DATANODE_DIRECTORYSCAN_MAX_NOTIFY_COUNT_KEY,
         DFSConfigKeys.DFS_DATANODE_DIRECTORYSCAN_MAX_NOTIFY_COUNT_DEFAULT);
     lastDirScannerNotifyTime = System.currentTimeMillis();
-    datasetSubLockCount = conf.getLong(DFSConfigKeys.DFS_DATANODE_DATASET_SUBLOCK_COUNT_KEY,
-        DFSConfigKeys.DFS_DATANODE_DATASET_SUBLOCK_COUNT_DEFAULT);
-    this.datasetSubLockStrategy = new ModDataSetSubLockStrategy(datasetSubLockCount);
+    this.datasetSubLockStrategy = new DataNodeLayoutSubLockStrategy();
   }
 
   /**

hadoop-hdfs-project/hadoop-hdfs/src/main/resources/hdfs-default.xml

@@ -6569,14 +6569,6 @@
     </description>
   </property>
 
-  <property>
-    <name>dfs.datanode.dataset.sublock.count</name>
-    <value>1000</value>
-    <description>
-      The dataset readwrite lock counts for a volume.
-    </description>
-  </property>
-
   <property>
     <name>dfs.client.fsck.connect.timeout</name>
     <value>60000ms</value>