Hadoop in Secure Mode

https://hadoop.apache.org/docs/stable/hadoop-project-dist/hadoop-common/SecureMode.html#:~:text=When%20Hadoop%20is%20configured%20to,or%20%2Fetc%2Fhosts%20files.

This document describes how to configure authentication for Hadoop in secure mode.

By default Hadoop runs in non-secure mode in which no actual authentication is required.By configuring Hadoop runs in secure mode, each user and service needs to be authenticated by Kerberos in order to use Hadoop services.