I'm setting up Impala Admission Control.
For the user.<username> placement rules, there is "Not recommended" remark "Use the resource pool that matches the username. (Not Recommended)"
In my use-case, specific limitation for a set (a dozen) of users should be applied. At the same time the group management is relatively hard, therefore, I would prefer the root.[username] approach.
I would like to better understand the drawbacks of this approach: are there any technical limitations from Impala point of view, or it is just a bad practice due to it is harder to maintain&support&manage (from Administrator's perspective)?