MAPREDUCE-4990. Construct debug strings conditionally in ShuffleHandler.Shuffle#sendMapOutput(). (kkambatl via tgraves)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.23@1458376 13f79535-47bb-0310-9956-ffa450edef68

hadoop-mapreduce-project/CHANGES.txt

@@ -28,6 +28,9 @@ Release 0.23.7 - UNRELEASED
     MAPREDUCE-5027. Shuffle does not limit number of outstanding connections
     (Robert Parker via jeagles)
 
+    MAPREDUCE-4990. Construct debug strings conditionally in 
+    ShuffleHandler.Shuffle#sendMapOutput(). (kkambatl via tgraves)
+
   OPTIMIZATIONS
 
     MAPREDUCE-4946. Fix a performance problem for large jobs by reducing the

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-shuffle/src/main/java/org/apache/hadoop/mapred/ShuffleHandler.java

@@ -494,15 +494,19 @@ public class ShuffleHandler extends AbstractService
           ContainerLocalizer.USERCACHE + "/" + user + "/"
               + ContainerLocalizer.APPCACHE + "/"
               + ConverterUtils.toString(appID) + "/output" + "/" + mapId;
-      LOG.debug("DEBUG0 " + base);
+      if (LOG.isDebugEnabled()) {
+        LOG.debug("DEBUG0 " + base);
+      }
       // Index file
       Path indexFileName = lDirAlloc.getLocalPathToRead(
           base + "/file.out.index", conf);
       // Map-output file
       Path mapOutputFileName = lDirAlloc.getLocalPathToRead(
           base + "/file.out", conf);
-      LOG.debug("DEBUG1 " + base + " : " + mapOutputFileName + " : " +
-          indexFileName);
+      if (LOG.isDebugEnabled()) {
+        LOG.debug("DEBUG1 " + base + " : " + mapOutputFileName + " : "
+            + indexFileName);
+      }
       IndexRecord info = 
         indexCache.getIndexInformation(mapId, reduce, indexFileName, user);
       final ShuffleHeader header =