HDFS-13831. Make block increment deletion number configurable. Contributed by Ryan Wu.

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

@@ -395,6 +395,11 @@ public class DFSConfigKeys extends CommonConfigurationKeys {
   public static final String  DFS_NAMENODE_STARTUP_DELAY_BLOCK_DELETION_SEC_KEY = "dfs.namenode.startup.delay.block.deletion.sec";
   public static final long    DFS_NAMENODE_STARTUP_DELAY_BLOCK_DELETION_SEC_DEFAULT = 0L;
 
+  /** Block deletion increment. */
+  public static final String DFS_NAMENODE_BLOCK_DELETION_INCREMENT_KEY =
+      "dfs.namenode.block.deletion.increment";
+  public static final int DFS_NAMENODE_BLOCK_DELETION_INCREMENT_DEFAULT = 1000;
+
   public static final String DFS_NAMENODE_SNAPSHOT_CAPTURE_OPENFILES =
       HdfsClientConfigKeys.DFS_NAMENODE_SNAPSHOT_CAPTURE_OPENFILES;
   public static final boolean DFS_NAMENODE_SNAPSHOT_CAPTURE_OPENFILES_DEFAULT =

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

@@ -428,12 +428,12 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
       FSNamesystem.class.getName() + ".audit");
 
   private final int maxCorruptFileBlocksReturn;
-  static int BLOCK_DELETION_INCREMENT = 1000;
   private final boolean isPermissionEnabled;
   private final UserGroupInformation fsOwner;
   private final String supergroup;
   private final boolean standbyShouldCheckpoint;
   private final int snapshotDiffReportLimit;
+  private final int blockDeletionIncrement;
 
   /** Interval between each check of lease to release. */
   private final long leaseRecheckIntervalMs;
@@ -909,6 +909,13 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
           DFSConfigKeys.DFS_NAMENODE_LIST_OPENFILES_NUM_RESPONSES +
               " must be a positive integer."
       );
+
+      this.blockDeletionIncrement = conf.getInt(
+          DFSConfigKeys.DFS_NAMENODE_BLOCK_DELETION_INCREMENT_KEY,
+          DFSConfigKeys.DFS_NAMENODE_BLOCK_DELETION_INCREMENT_DEFAULT);
+      Preconditions.checkArgument(blockDeletionIncrement > 0,
+          DFSConfigKeys.DFS_NAMENODE_BLOCK_DELETION_INCREMENT_KEY +
+              " must be a positive integer.");
     } catch(IOException e) {
       LOG.error(getClass().getSimpleName() + " initialization failed.", e);
       close();
@@ -3094,7 +3101,7 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
     while (iter.hasNext()) {
       writeLock();
       try {
-        for (int i = 0; i < BLOCK_DELETION_INCREMENT && iter.hasNext(); i++) {
+        for (int i = 0; i < blockDeletionIncrement && iter.hasNext(); i++) {
           blockManager.removeBlock(iter.next());
         }
       } finally {

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

@@ -5160,4 +5160,14 @@
       will throw NameNodeFormatException.
     </description>
   </property>
+
+  <property>
+    <name>dfs.namenode.block.deletion.increment</name>
+    <value>1000</value>
+    <description>
+      The number of block deletion increment.
+      This setting will control the block increment deletion rate to
+      ensure that other waiters on the lock can get in.
+    </description>
+  </property>
 </configuration>

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

@@ -49,6 +49,7 @@ public class TestLargeDirectoryDelete {
   static {
     CONF.setLong(DFSConfigKeys.DFS_BLOCK_SIZE_KEY, 1);
     CONF.setInt(DFSConfigKeys.DFS_BYTES_PER_CHECKSUM_KEY, 1);
+    CONF.setInt(DFSConfigKeys.DFS_NAMENODE_BLOCK_DELETION_INCREMENT_KEY, 1);
   }
   
   /** create a file with a length of <code>filelen</code> */
@@ -137,7 +138,6 @@ public class TestLargeDirectoryDelete {
     threads[1].start();
     
     final long start = Time.now();
-    FSNamesystem.BLOCK_DELETION_INCREMENT = 1;
     mc.getFileSystem().delete(new Path("/root"), true); // recursive delete
     final long end = Time.now();
     threads[0].endThread();