svn merge -c 1292626 from trunk for HDFS-2981.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.23@1292627 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -61,6 +61,10 @@ Release 0.23.2 - UNRELEASED
     dfs.client.block.write.replace-datanode-on-failure.enable to be mistakenly
     disabled. (atm)
 
+    HDFS-2981. In hdfs-default.xml, the default value of
+    dfs.client.block.write.replace-datanode-on-failure.enable should be true.
+    (szetszwo)
+
 Release 0.23.1 - 2012-02-17 
 
   INCOMPATIBLE CHANGES

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

@@ -347,7 +347,7 @@ creations/deletions), or "all".</description>
 
 <property>
   <name>dfs.client.block.write.replace-datanode-on-failure.enable</name>
-  <value>false</value>
+  <value>true</value>
   <description>
     If there is a datanode/network failure in the write pipeline,
     DFSClient will try to remove the failed datanode from the pipeline