[
https://issues.apache.org/jira/browse/YARN-392?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13583651#comment-13583651
]
Alejandro Abdelnur commented on YARN-392:
-----------------------------------------
I think the 2nd approach (introducing an ID in the ResourceRequest) is
preferable to the boolean flag as it will allow to express a set of OR
localities.
I've been thinking a bit on how adding/handling this new piece of information
would affect the RM/Scheduler.
After running some use cases on the whiteboard, I think handling this ID is
entirely optional to the scheduler to implement, the scheduler could completely
ignore this ID and things would still work correctly. In such scenario, an AM
would just receive additional container allocations which in turn it would
return them back to the RM without using them.
A scheduler implementing this ID tracking functionality it would require to
have an additional crossrefence Map keying off pending requests with AppId+ID
to be able to access and decrement the corresponding outstanding resource
request. And this does not seem overly complicated.
One small change I would suggest is the resource allocation response to the AM
to include the ID that is being satisfied (in case the scheduler handles IDs).
This will help the AM to do a more optimal decision and bookkeeping on what to
use the received allocation for.
> Make it possible to schedule to specific nodes without dropping locality
> ------------------------------------------------------------------------
>
> Key: YARN-392
> URL: https://issues.apache.org/jira/browse/YARN-392
> Project: Hadoop YARN
> Issue Type: Sub-task
> Reporter: Bikas Saha
> Assignee: Sandy Ryza
> Attachments: YARN-392.patch
>
>
> Currently its not possible to specify scheduling requests for specific nodes
> and nowhere else. The RM automatically relaxes locality to rack and * and
> assigns non-specified machines to the app.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira
