HADOOP-3448. Improve the text in the assertion making sure the

layout versions are consistent in the data node. Contributed by
Steve Loughran.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/core/trunk@663321 13f79535-47bb-0310-9956-ffa450edef68

CHANGES.txt

@@ -204,6 +204,10 @@ Trunk (unreleased changes)
     HADOOP-3486. Change default for initial block report to 0 seconds
     and document it. (Sanjay Radia via omalley)
 
+    HADOOP-3448. Improve the text in the assertion making sure the
+    layout versions are consistent in the data node. (Steve Loughran
+    via omalley)
+
   OPTIMIZATIONS
 
     HADOOP-3274. The default constructor of BytesWritable creates empty 

src/java/org/apache/hadoop/dfs/DataNode.java

@@ -397,7 +397,8 @@ public class DataNode extends Configured
       throw new IOException( errorMsg );
     }
     assert FSConstants.LAYOUT_VERSION == nsInfo.getLayoutVersion() :
-      "Data-node and name-node layout versions must be the same.";
+      "Data-node and name-node layout versions must be the same."
+      + "Expected: "+ FSConstants.LAYOUT_VERSION + " actual "+ nsInfo.getLayoutVersion();
     return nsInfo;
   }