HDFS-4882. Prevent the Namenode's LeaseManager from looping forever in checkLeases (Ravi Prakash via Colin P. McCabe)
(cherry picked from commit daacbc18d739d030822df0b75205eeb067f89850)
HDFS-7419. Improve error messages for DataNode hot swap drive feature (Lei Xu via Colin P. Mccabe)
(cherry picked from commit f636f9d9439742d7ebaaf21f7e22652403572c61)
HDFS-7412. Move RetryCache to NameNodeRpcServer. Contributed by Haohui Mai.
CHANGES.txt: add HDFS-4882
CHANGES.txt: add HDFS-7419
YARN-1984. LeveldbTimelineStore does not handle db exceptions properly. Contributed by Varun Saxena
(cherry picked from commit 1ce4d33c2dc86d711b227a04d2f9a2ab696a24a1)
YARN-2697. Remove useless RMAuthenticationHandler. Contributed by Haosong Huang.

(cherry picked from commit e37a4ff0c1712a1cb80e0412ec53a5d10b8d30f9)
HDFS-7436. Consolidate implementation of concat(). Contributed by Haohui Mai.
HDFS-7303. NN UI fails to distinguish datanodes on the same host. Contributed by Benoy Antony.
HADOOP-11322. key based ACL check in KMS always check KeyOpType.MANAGEMENT even actual KeyOpType is not MANAGEMENT. (Dian Fu via yliu)
Merge remote-tracking branch 'remotes/origin/branch-2' into branch-2