I'd like to get Hive off of DistributedFileSystem and DFSClient in Hadoop23Shims if possible. DFS is also a private API, and there's a lot going on here that makes me uncomfortable as an HDFS developer. This is additional work beyond just the immediate scope of this JIRA.
As a start, I think we should expose getKeyProvider in HDFSAdmin. isHdfsEncryptionEnabled is just a check for if getKeyProvider is null, so we don't need to expose that too.
As part of this, we should also see if the ERROR logging mentioned in
HIVE-16047 and HDFS-7931 needs to be quashed some more.