Eric Payne commented on YARN-2056:

[~leftnoteasy], I'm sorry, but there is one more thing that needs to be 
modified with the current design. The current patch only allows the disable 
queue preemption flag to be set on leaf queues. However, after discussing his 
internally, we need to be able to have leaf queues inherit this property from 
their parent.

Only setting the disable queue preemption property on leaf queues was an 
intentional design decision to begin with. This was because inheriting this 
property from a parent would impose a new set of requirements. Consider this 
use case:

- root queue has children A and B
- A has children A1 and A2
- B has children B1 and B2
- A should not be preemptable
- A1 and A2 should be able to preempt each other

In this use case, if A is over capacity, B should not be able to preempt. 
However, if A1 is over capacity, A2 should be able to preempt A1.

I believe I can make the leaf nodes inherit this property from its parent and 
still be able to solve for the above use case. I will be putting up a new patch 
(hopefully) tomorrow.

> Disable preemption at Queue level
> ---------------------------------
>                 Key: YARN-2056
>                 URL: https://issues.apache.org/jira/browse/YARN-2056
>             Project: Hadoop YARN
>          Issue Type: Sub-task
>          Components: resourcemanager
>    Affects Versions: 2.4.0
>            Reporter: Mayank Bansal
>            Assignee: Eric Payne
>         Attachments: YARN-2056.201408202039.txt, YARN-2056.201408260128.txt, 
> YARN-2056.201408310117.txt, YARN-2056.201409022208.txt, 
> YARN-2056.201409181916.txt, YARN-2056.201409210049.txt, 
> YARN-2056.201409232329.txt, YARN-2056.201409242210.txt, 
> YARN-2056.201410132225.txt, YARN-2056.201410141330.txt, 
> YARN-2056.201410232244.txt, YARN-2056.201410311746.txt, 
> YARN-2056.201411041635.txt
> We need to be able to disable preemption at individual queue level

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