merge MAPREDUCE-5352 from trunk. Optimize node local splits generated by CombineFileInputFormat. (sseth)


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1509346 13f79535-47bb-0310-9956-ffa450edef68
HDFS-4962. Merging change r1501851 from trunk

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1509386 13f79535-47bb-0310-9956-ffa450edef68
svn merge -c 1509389 FIXES: YARN-573. Shared data structures in Public Localizer and Private Localizer are not Thread safe. Contributed by Omkar Vinit Joshi


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1509393 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/branch-2' into branch-2-gd
Merge remote branch 'origin/branch-2-gd' into fb-MAPREDUCE-4884-branch-2-gd