How to add user in supergroup of hdfs in linux

Question

I was working on hdfs then i found something that permissions checks are not performed for the super-user. If my linux user is jino and i want add jino to group of super-user. So permissions denied will not occur, is it feasible to do that in hdfs configuration. And if there is no problem in assigning the user to supergroup then how to do it ?

Answer 1

Yes , now i have whole idea how users and group should be created on any hdfs cluster. First of all i didn't find any group named supergroup in /etc/group.

So good practice is to create your own supergroup.

1. sudo addgroup testgroup
2. Then create users as many you want. e.g adduser jino
3. Then add these users to testgroup
4. Then edit hdfs-site.xml property and add this property dfs.permissions.superusergroup, value will be your group name
5. Now you can create any number of folders in hdfs and then assign ownership as yourusername:supergroup e.g jino:testgroup

Its not a good pratice to run jobs as super-user. Be advised to create a new group and new account for hadoop/hdfs and then give required permissions as below

$ sudo addgroup hadoop
$ sudo adduser --ingroup hadoop hduser

$ sudo chown hduser:hadoop {directory path}

                      OR

You can also add the user to hadoop group.

$ sudo adduser --ingroup hadoop jino

I hope this helps :)