[ 
https://issues.apache.org/jira/browse/YARN-8149?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16434342#comment-16434342
 ] 

Wangda Tan commented on YARN-8149:
----------------------------------

[~jlowe] / [~eepayne] / [~cheersyang] / [~Tao Yang] / [~sunilg]. 

Could u share your thoughts on this? If we can remove this, reservation logic 
can be simplified a lot.

> Revisit behavior of Re-Reservation in Capacity Scheduler
> --------------------------------------------------------
>
>                 Key: YARN-8149
>                 URL: https://issues.apache.org/jira/browse/YARN-8149
>             Project: Hadoop YARN
>          Issue Type: Bug
>            Reporter: Wangda Tan
>            Priority: Critical
>
> Frankly speaking, I'm not sure why we need the re-reservation. The formula is 
> not that easy to understand:
> Inside: 
> {{org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.allocator.RegularContainerAllocator#shouldAllocOrReserveNewContainer}}
> {code:java}
> starvation = re-reservation / (#reserved-container * 
>      (1 - min(requested-resource / max-alloc, 
>               max-alloc - min-alloc / max-alloc))
> should_allocate = starvation + requiredContainers - reservedContainers > 
> 0{code}
> I think we should be able to remove the starvation computation, just to check 
> requiredContainers > reservedContainers should be enough.
> In a large cluster, we can easily overflow re-reservation to MAX_INT, see 
> YARN-7636. 
>  



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)

---------------------------------------------------------------------
To unsubscribe, e-mail: yarn-issues-unsubscr...@hadoop.apache.org
For additional commands, e-mail: yarn-issues-h...@hadoop.apache.org

Reply via email to