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How to find the name of supergroup in hadoop and list all the members of the group?

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Rising Star

Hi there,

How to find the name of supergroup in hadoop and list all the members of the group?

I know hdfs is the super user in hadoop, but SuperGroup name

1 ACCEPTED SOLUTION

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@Jeeva Jeeva - There is a property "dfs.permissions.superusergroup" in hdfs-site.xml which specifies the superusergroup.

Please see below apache guide for HDFS Permissions:

https://hadoop.apache.org/docs/r2.4.1/hadoop-project-dist/hadoop-hdfs/HdfsPermissionsGuide.html

To list all the users belonging to the supergroup, its just like getting users belonging to a group in linux. Below is good article on that:

https://www.cyberciti.biz/faq/linux-list-all-members-of-a-group/

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15 REPLIES 15

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Also to find the namenode hosts, just look at the property value for dfs.namenode.rpc-address in hdfs-site.xml

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Rising Star

Is there any way to find it from ambari without logging to NameNode?

If it is not, how to log on to the namenode from linux(edge node)? sorry for the trivial questiion.

I tried to login from putty, i got exception.

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I dont think we can get this from Ambari as this is a Linux file, and Ambari is not involved in maintaining that.

As far as logging on to the Namenode, it should be the similar as how you logged on to any other host on the cluster.

We use ssh with a keypair to logon, but thats your environment specific. So, if you have the IP, you should be able to logon to the Namenode host.

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Rising Star

Anyway.. Thanks for your involvement on this issue. Once i resolved it, I will let you know. I used putty to login but got exception.

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Ok sure. Yeah I cant say how to logon to your Namenode linux machine. Someone, in your team over there might help.

Also, can you please accept the answer for how to find the supergroup in Hdfs. As, I think you found that information. Thanks!

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Rising Star

Hi Mahesh,

There is no way to list all members of supergroup. But, we can run for individual user to see if they are belong to the group by using the below command.

hdfs groups <username>

Once again, thanks for time .