Add default config values to hdfs-default.xml.

Author: WangChengWei

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

@@ -481,10 +481,12 @@ public class DFSConfigKeys extends CommonConfigurationKeys {
       "dfs.namenode.block.deletion.increment";
   public static final int DFS_NAMENODE_BLOCK_DELETION_INCREMENT_DEFAULT = 1000;
 
+  /** The limit of single lock holding duration.*/
   public static final String DFS_NAMENODE_BLOCK_DELETION_LOCK_THRESHOLD_MS =
       "dfs.namenode.block.deletion.lock.threshold.ms";
   public static final int DFS_NAMENODE_BLOCK_DELETION_LOCK_THRESHOLD_MS_DEFAULT =
       50;
+  /** The sleep interval for releasing lock.*/
   public static final String DFS_NAMENODE_BLOCK_DELETION_UNLOCK_INTERVAL_MS =
       "dfs.namenode.block.deletion.unlock.interval.ms";
   public static final int DFS_NAMENODE_BLOCK_DELETION_UNLOCK_INTERVAL_MS_DEFAULT =

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

@@ -6109,6 +6109,25 @@
     </description>
   </property>
 
+  <property>
+    <name>dfs.namenode.block.deletion.lock.threshold.ms</name>
+    <value>50</value>
+    <description>
+      The limit of single time lock holding duration for the block asynchronous
+      deletion thread.
+    </description>
+  </property>
+
+  <property>
+    <name>dfs.namenode.block.deletion.unlock.interval.ms</name>
+    <value>10</value>
+    <description>
+      The sleep interval for yield lock.
+      When the single time lock holding duration of the block asynchronous deletion
+      thread exceeds limit, sleeping to yield lock.
+    </description>
+  </property>
+
   <property>
     <name>dfs.namenode.rpc-address.auxiliary-ports</name>
     <value></value>