[jira] [Commented] (YARN-1198) Capacity Scheduler headroom calculation does not work as expected

["Craig Welch (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/YARN-1198?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14154057#comment-14154057 ] 

Craig Welch commented on YARN-1198:
-----------------------------------

Sorry, the above was off - the conversation happened offline, here was the tweak to .7 that Jian suggested:

Hi Craig, I looked at your patch again. It's similar to what I thought. One thing is that now that headRoom is not application specific, it doesn't belong to application any more. We may make a member of LeafQueue#User. From CapacityScheduler#allocate, directly call LeafQueue #getAndCalculateHeadRoom , not going through SchedulerApplicationAttempt route to get the HeadRoom. I think this is simpler. do you think this will work?

> We may make a member of LeafQueue#User. To clarify: make the headRoom a variable of LeafQueue#User, and remove that from SchedulerAttempt

we might, in this approach, do what we are doing in .7 but without the HeadroomProvider at all... I'm going to give a go at this...

> Capacity Scheduler headroom calculation does not work as expected
> -----------------------------------------------------------------
>
>                 Key: YARN-1198
>                 URL: https://issues.apache.org/jira/browse/YARN-1198
>             Project: Hadoop YARN
>          Issue Type: Bug
>            Reporter: Omkar Vinit Joshi
>            Assignee: Craig Welch
>         Attachments: YARN-1198.1.patch, YARN-1198.2.patch, YARN-1198.3.patch, YARN-1198.4.patch, YARN-1198.5.patch, YARN-1198.6.patch, YARN-1198.7.patch, YARN-1198.8.patch
>
>
> Today headroom calculation (for the app) takes place only when
> * New node is added/removed from the cluster
> * New container is getting assigned to the application.
> However there are potentially lot of situations which are not considered for this calculation
> * If a container finishes then headroom for that application will change and should be notified to the AM accordingly.
> * If a single user has submitted multiple applications (app1 and app2) to the same queue then
> ** If app1's container finishes then not only app1's but also app2's AM should be notified about the change in headroom.
> ** Similarly if a container is assigned to any applications app1/app2 then both AM should be notified about their headroom.
> ** To simplify the whole communication process it is ideal to keep headroom per User per LeafQueue so that everyone gets the same picture (apps belonging to same user and submitted in same queue).
> * If a new user submits an application to the queue then all applications submitted by all users in that queue should be notified of the headroom change.
> * Also today headroom is an absolute number ( I think it should be normalized but then this is going to be not backward compatible..)
> * Also  when admin user refreshes queue headroom has to be updated.
> These all are the potential bugs in headroom calculations



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)