HDFS-15728. Update description of dfs.datanode.handler.count in hdfs-default.xml. Contributed by liuyan.(#2534)

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

@@ -121,7 +121,9 @@
 <property>
   <name>dfs.datanode.handler.count</name>
   <value>10</value>
-  <description>The number of server threads for the datanode.</description>
+  <description>
+     The number of Datanode RPC server threads that listen to
+     requests from client.</description>
 </property>
 
 <property>