How to create user in Hadoop with Limited Access ?
MapR makes use of the users that are configured at the Operating System level - so, they first must exist there (with the same UID and GID on every node). Once a user exists at the OS level, you can assign cluster, volume, and filesystem permissions using maprcli commands or the user interface. For read/write access to cluster data, we honor the POSIX rwx settings set at the OS level, but you can also make access more restrictive by applying Access Control Expressions to users, groups, or custom roles that you define.
You can find more information here: Setting User Permissions
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