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Can't access ambari hive view with an username in uppercase.

Expert Contributor

Hello community!

I'm using ambari 2.4.1 and I'm trying to use ambari hive view, the problem is that the username is in uppercase and his HDFS user folder is also in uppercase so when I try to create the user with uppercase in ambari, it converts it to lowercase and then when trying to access ambari hive view it propmt an error because it doesn't find the lowercase user folder.

I only have this problem in a not secured cluster, in the secured cluster with one way trust relationship with my AD it works properly.

Do you know how to fix this?

Thank you in advance!


@Juan Manuel Nieto

It seems like you have found a bug. A similar bug was fixed, but in the opposite direction, for Ambari 2.5.0 - see AMBARI-18813. In the other case, lowercase usernames are converted to mixed cased usernames due to case differences with the usernames stored in the associated LDAP server. In either case, the issue seems to be that Ambari uses case-insensitive usernames where HDFS and other Hadoop services use case-sensitive usernames.

Unfortunately, there is no easy way to solve this since both, case-sensitive and case-insensitive usernames, are at play. My argument against case-sensitive usernames is that they are confusing and error prone. Imagine a system where, rlevas, Rlevas, RLevas, and RLEVAS are all different users. Or how about usernames like Ismith vs lsmith. Using the font that I am looking at (I am not sure what font, though), lowercase L (L --> l) looks exactly like uppercase I (I --> i).

In any case, my opinion is obviously not shared by all since operating systems like CentOS and frameworks like Hadoop are case-sensitive.

That said, I am trying to propose changes for Ambari 3.0 that should help to fix these inconsistency issues. One part of my proposal is to have case-sensitive usernames for Ambari, but allow the user accounts to specify a "local" username value that is case-sensitive. I will eventually make this proposal public... but I am still reviewing it.

For now, I think you may need to change the case of the offending accounts to be all lowercase in order to get things working.

I'd like to describe my recent experience with an LDAP user in capitals. It works as you noticed but it's confusing. It syncs fine, but in the list of Ambari users it's shown in lower-case. I can login in capitals, but the current user in Ambari is shown in lower-case. And when I do something from Ambari views, like upload a file, the file owner in hdfs appears (correctly) in capitals, and my home directory on HDFS set in capitals is observed. Then one LDAP user whose username is in capitals and is already synced in Ambari, created an Ambari local user with the same username in capitals, and he couldn't logged in! We had to remove the local user in capitals, and after that he could login as the AD user in capitals (stored in lower-case on Ambari).

Expert Contributor

@Predrag Minovic that's interesting, I'll keep it in mind, because we actually have local usernames with lowercase in ambari, which are going to be sync in capital letters from AD.

Thank you! I think you just avoided me a future headche 😉

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