Why does Datameer need the Kerberos principals for the Hadoop environment? Shouldn’t Datameer only need to be aware of its own Kerberos principal and keytab file?
No. Datameer needs Kerberos principals to access related services such as the Hadoop Distributed Files system (HDFS) or Resource Manager (RM). For more information, you can have a look into Kerberos Concepts - Principals, Keytabs and Delegation Tokens, Kerberos Principals, and Creating Principals and Keytab Files.