MAPREDUCE-2770. Improve hadoop.job.history.location doc in mapred-default.xml. Contributed by Sandy Ryza.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1@1388381 13f79535-47bb-0310-9956-ffa450edef68

CHANGES.txt

@@ -104,6 +104,9 @@ Release 1.2.0 - unreleased
     HADOOP-8832. Port generic service plugin mechanism from HADOOP-5257
     to branch-1. (backported by Brandon Li via suresh) 
 
+    MAPREDUCE-2770. Improve hadoop.job.history.location doc in
+    mapred-default.xml. (Sandy Ryza via tomwhite)
+
   OPTIMIZATIONS
 
     HDFS-2533. Backport: Remove needless synchronization on some FSDataSet

src/mapred/mapred-default.xml

@@ -10,9 +10,12 @@
 <property>
   <name>hadoop.job.history.location</name>
   <value></value>
-  <description> If job tracker is static the history files are stored 
-  in this single well known place. If No value is set here, by default,
-  it is in the local file system at ${hadoop.log.dir}/history.
+  <description> The location where jobtracker history files are stored.
+  The value for this key is treated as a URI, meaning that the files 
+  can be stored either on HDFS or the local file system.  If no value is 
+  set here, the location defaults to the local file system, at 
+  file:///${hadoop.log.dir}/history.  If the URI is missing a scheme,
+  fs.default.name is used for the file system.
   </description>
 </property>