HDFS-7279. Use netty to implement DatanodeWebHdfsMethods. Contributed by Haohui Mai.
HADOOP-11157. ZKDelegationTokenSecretManager never shuts down listenerThreadPool. Contributed by Arun Suresh.
YARN-2414. RM web UI: app page will crash if app is failed before any attempt has been created. Contributed by Wangda Tan
HDFS-7146. NFS ID/Group lookup requires SSSD enumeration on the server. Contributed by Yongjun Zhang
HADOOP-11311. Restrict uppercase key names from being created with JCEKS.