MAPREDUCE-3317. Rumen TraceBuilder is emiting null as hostname. (Ravi Gummadi via mahadev) - Merging r1195814 from trunk.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.23@1195815 13f79535-47bb-0310-9956-ffa450edef68

hadoop-mapreduce-project/CHANGES.txt

@@ -1870,6 +1870,9 @@ Release 0.23.0 - Unreleased
     MAPREDUCE-3316. Rebooted link is not working properly. 
     (Bhallamudi Venkata Siva Kamesh via mahadev)
 
+    MAPREDUCE-3317. Rumen TraceBuilder is emiting null as hostname.
+    (Ravi Gummadi via mahadev)
+
 Release 0.22.0 - Unreleased
 
   INCOMPATIBLE CHANGES

hadoop-mapreduce-project/src/tools/org/apache/hadoop/tools/rumen/LoggedTaskAttempt.java

@@ -49,7 +49,6 @@ public class LoggedTaskAttempt implements DeepCompare {
   long startTime = -1L;
   long finishTime = -1L;
   String hostName;
-  String rackName;
 
   long hdfsBytesRead = -1L;
   long hdfsBytesWritten = -1L;
@@ -329,9 +328,11 @@ public class LoggedTaskAttempt implements DeepCompare {
     return hostName;
   }
 
+
+  // hostName is saved in the format rackName/NodeName
   void setHostName(String hostName, String rackName) {
-    this.hostName = hostName == null || this.rackName == null ? null
-        : hostName.intern() + "/" + rackName.intern();
+    this.hostName = hostName == null || rackName == null ? null
+        : rackName.intern() + "/" + hostName.intern();
   }
 
   public long getHdfsBytesRead() {