YARN-2604. Scheduler should consider max-allocation-* in conjunction with the largest node. (Robert Kanter via kasha)
HDFS-7420. Delegate permission checks to FSDirectory. Contributed by Haohui Mai.
YARN-2679. Add metric for container launch duration. (Zhihai Xu via kasha)
Update release date for 2.5.2
YARN-2669. FairScheduler: queue names shouldn't allow periods (Wei Yan via Sandy Ryza)
HDFS-7425. NameNode block deletion logging uses incorrect appender. Contributed by Chris Nauroth.
HDFS-7331. Add Datanode network counts to datanode jmx page. Contributed by Charles Lamb.
MAPREDUCE-5785. Derive heap size or mapreduce.*.memory.mb automatically. (Gera Shegalov and Karthik Kambatla via kasha)
HDFS-7403. Inaccurate javadoc of  BlockUCState#COMPLETE state. (Yongjun Zhang via yliu)
HDFS-4882. Prevent the Namenode's LeaseManager from looping forever in checkLeases (Ravi Prakash via Colin P. McCabe)
HDFS-7419. Improve error messages for DataNode hot swap drive feature (Lei Xu via Colin P. Mccabe)
HDFS-7412. Move RetryCache to NameNodeRpcServer. Contributed by Haohui Mai.
CHANGES.txt: add HDFS-4882
CHANGES.txt: add HDFS-7419
HADOOP-10926. Improve smart-apply-patch.sh to apply binary diffs (cmccabe)
YARN-1984. LeveldbTimelineStore does not handle db exceptions properly. Contributed by Varun Saxena
YARN-2697. Remove useless RMAuthenticationHandler. Contributed by Haosong Huang.
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)