Major Description
When the "_HOST" replacement feature of Kerberos principal names is used, the various Hadoop daemons must determine their own canonical hostname in order to form their principal name.
Presently, the NN determines its own hostname based on the configured value of "fs.default.name", whereas the DNs determine their hostnames based on the result of "InetAddress.getLocalHost().getCanonicalHostName()". This asymmetry can cause confusion during configuration of a secure cluster.