[ 
https://issues.apache.org/jira/browse/SPARK-4352?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14567016#comment-14567016
 ] 

Saisai Shao commented on SPARK-4352:
------------------------------------

Hi [~sandyr], thanks a lot for your suggestion. IIUC the algorithm you describe 
is trying to make the executor request be proportional to the node preference, 
say your desired tasks on cluster are 3 : 3 : 2 : 1, so you're trying to 
allocate the executors following this, but I'm curious about  algorithm on 7 
and 18 situation, what you describe is:

requests for 5 executors with nodes = <a, b, c, d>
requests for 2 executors with nodes = <a, b, c>

that is 7 : 7 : 7 : 5

is it better like this:

requests for 2 executors with nodes = <a, b, c, d>
requests for 2 executors with nodes = <a, b, c>
requests for 3 executors with nodes = <a, b>

here is 7 : 7 : 4 : 2

Also for 18 situation, why not:

requests for 6 executors with nodes = <a, b, c, d>
requests for 6 executors with nodes = <a, b, c>
requests for 6 executors with nodes = <a, b>

Would you please help to explain it, maybe I missed in some places:).


> Incorporate locality preferences in dynamic allocation requests
> ---------------------------------------------------------------
>
>                 Key: SPARK-4352
>                 URL: https://issues.apache.org/jira/browse/SPARK-4352
>             Project: Spark
>          Issue Type: Improvement
>          Components: Spark Core, YARN
>    Affects Versions: 1.2.0
>            Reporter: Sandy Ryza
>            Assignee: Saisai Shao
>            Priority: Critical
>         Attachments: Supportpreferrednodelocationindynamicallocation.pdf
>
>
> Currently, achieving data locality in Spark is difficult unless an 
> application takes resources on every node in the cluster.  
> preferredNodeLocalityData provides a sort of hacky workaround that has been 
> broken since 1.0.
> With dynamic executor allocation, Spark requests executors in response to 
> demand from the application.  When this occurs, it would be useful to look at 
> the pending tasks and communicate their location preferences to the cluster 
> resource manager. 



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

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

Reply via email to