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https://issues.apache.org/jira/browse/YARN-9892?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17016160#comment-17016160
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Wangda Tan commented on YARN-9892:
----------------------------------

Spent a bit time to look at the code, not fully dig into all details, but I 
think there's significant different between FS and CS to handle resource 
calculator:

In CS, resource calculator is initialized and used across all the logic.

In FS, there's a separate SchedulingPolicy, which is a wrapper of resource 
calculator. It covers areas like compute shares, sort apps/queues, compute 
headrooms, etc.

For the patch uploaded in the Jira, it handles a small area only, which is sort 
apps.

I want to hear thoughts from [~wilfreds] that why the drf for different queues 
is a P0 feature, to me DRF is just an natural extension of Fair (which 
considers multiple resource types). I still think we should optimize the logic 
and knobs to the users. Cluster admin has to re-tune lots of queue capacities 
and SLAs after conversion, we cannot maintain all the different behaviors.

And since there's still a global configuration of ResourceCalculator, which is 
used by 
org.apache.hadoop.yarn.server.resourcemanager.scheduler.SchedulerUtils#getNormalizedResource
 when the request came in to the scheduler. I'm a bit confused that 
SchedulingPolicy could conflict with the global ResourceCalculator.

> Capacity scheduler: support DRF ordering policy on queue level
> --------------------------------------------------------------
>
>                 Key: YARN-9892
>                 URL: https://issues.apache.org/jira/browse/YARN-9892
>             Project: Hadoop YARN
>          Issue Type: Sub-task
>          Components: capacity scheduler
>            Reporter: Peter Bacsko
>            Assignee: Manikandan R
>            Priority: Major
>         Attachments: YARN-9892-003.patch, YARN-9892.001.patch, 
> YARN-9892.002.patch
>
>
> Capacity scheduler does not support DRF (Dominant Resource Fairness) ordering 
> policy on queue level. Only "fifo" and "fair" are accepted for 
> {{yarn.scheduler.capacity.<queue-path>.ordering-policy}}.
> DRF can only be used globally if 
> {{yarn.scheduler.capacity.resource-calculator}} is set to 
> DominantResourceCalculator.



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