MAPREDUCE-5761. Added a simple log message to denote when encrypted shuffle is on in the shuffle-handler. Contributed by Jian He.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1571514 13f79535-47bb-0310-9956-ffa450edef68
YARN-1734. Fixed ResourceManager to update the configurations when it transits from standby to active mode so as to assimilate any changes that happened while it was in standby mode. Contributed by Xuan Gong.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1571539 13f79535-47bb-0310-9956-ffa450edef68
HDFS-5922. DN heartbeat thread can get stuck in tight loop. (Arpit Agarwal)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1571542 13f79535-47bb-0310-9956-ffa450edef68
Merge r1569890 through r1571553 from trunk.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/HDFS-5535@1571554 13f79535-47bb-0310-9956-ffa450edef68