MAPREDUCE-6068. Illegal progress value warnings in map tasks. Contributed by Binglin Chang.

hadoop-mapreduce-project/CHANGES.txt

@@ -677,8 +677,8 @@ Release 2.8.0 - UNRELEASED
     MAPREDUCE-6550. archive-logs tool changes log ownership to the Yarn
     user when using DefaultContainerExecutor (rkanter)
 
-   MAPREDUCE-6419. JobHistoryServer doesn't sort properly based on Job ID when Job id's 
-   exceed 9999. (Mohammad Shahid Khan via rohithsharmaks)
+    MAPREDUCE-6419. JobHistoryServer doesn't sort properly based on Job ID when Job id's 
+    exceed 9999. (Mohammad Shahid Khan via rohithsharmaks)
 
     MAPREDUCE-6589. TestTaskLog outputs a log under directory other than
     target/test-dir. (aajisaka)
@@ -686,6 +686,9 @@ Release 2.8.0 - UNRELEASED
     MAPREDUCE-6593. TestJobHistoryEventHandler.testTimelineEventHandling fails
     on trunk because of NPE. (Naganarasimha G R via aajisaka)
 
+    MAPREDUCE-6068. Illegal progress value warnings in map tasks. (Binglin Chang
+    via junping_du)
+
 Release 2.7.3 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapred/Merger.java

@@ -519,7 +519,7 @@ public class Merger {
       boolean hasNext = reader.nextRawKey();
       long endPos = reader.getReader().bytesRead;
       totalBytesProcessed += endPos - startPos;
-      mergeProgress.set(totalBytesProcessed * progPerByte);
+      mergeProgress.set(Math.min(1.0f, totalBytesProcessed * progPerByte));
       if (hasNext) {
         adjustTop();
       } else {
@@ -571,7 +571,7 @@ public class Merger {
       }
       long endPos = minSegment.getReader().bytesRead;
       totalBytesProcessed += endPos - startPos;
-      mergeProgress.set(totalBytesProcessed * progPerByte);
+      mergeProgress.set(Math.min(1.0f, totalBytesProcessed * progPerByte));
       return true;
     }
 
@@ -698,7 +698,7 @@ public class Merger {
           
           totalBytesProcessed += startBytes;         
           if (totalBytes != 0)
-            mergeProgress.set(totalBytesProcessed * progPerByte);
+            mergeProgress.set(Math.min(1.0f, totalBytesProcessed * progPerByte));
           else
             mergeProgress.set(1.0f); // Last pass and no segments left - we're done