Don't get me started on setting up production hdfs and hadoop that is a nightmare. It is comparatively well documented with lots of people running it! As soon as you get into the weeds with kerberos and HA mode forget about the documentation explaining anything properly. Cargo culting from random blog posts, reading the source, and just playing around with config files is the name of the game. There are some weird interactions between KDC settings and some of the daemons that are not documented at all.