[ 
https://issues.apache.org/jira/browse/YARN-6050?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15800128#comment-15800128
 ] 

Wangda Tan commented on YARN-6050:
----------------------------------

Thanks [~rkanter] for updating patch. A couple of comments/questions:

Not sure if code below works well:

{code}  
442           List<ResourceRequest> amReqs =
443               submissionContext.getAMContainerResourceRequests();
444           if (amReqs == null || amReqs.isEmpty()) {
445             @SuppressWarnings("deprecation") ResourceRequest amReq =
446                 submissionContext.getAMContainerResourceRequest();
{code}

Since now {{getAMContainerResourceRequests}} and 
{{getAMContainerResourceRequest}} shares the same data field, so if line 444 is 
null, line 445 should be null as well, correct? 

So I think we should not use {{getAMContainerResourceRequest}} at all, to make 
a backward-compatible behavior, if AM resource request has length == 1, we can 
change its resourceName to ANY instead of through exception, correct? 

And when length > 1, we can check existence of ANY request and throw exception.

Thoughts?

> AMs can't be scheduled on racks or nodes
> ----------------------------------------
>
>                 Key: YARN-6050
>                 URL: https://issues.apache.org/jira/browse/YARN-6050
>             Project: Hadoop YARN
>          Issue Type: Bug
>    Affects Versions: 2.9.0, 3.0.0-alpha2
>            Reporter: Robert Kanter
>            Assignee: Robert Kanter
>         Attachments: YARN-6050.001.patch, YARN-6050.002.patch, 
> YARN-6050.003.patch
>
>
> Yarn itself supports rack/node aware scheduling for AMs; however, there 
> currently are two problems:
> # To specify hard or soft rack/node requests, you have to specify more than 
> one {{ResourceRequest}}.  For example, if you want to schedule an AM only on 
> "rackA", you have to create two {{ResourceRequest}}, like this:
> {code}
> ResourceRequest.newInstance(PRIORITY, ANY, CAPABILITY, NUM_CONTAINERS, false);
> ResourceRequest.newInstance(PRIORITY, "rackA", CAPABILITY, NUM_CONTAINERS, 
> true);
> {code}
> The problem is that the Yarn API doesn't actually allow you to specify more 
> than one {{ResourceRequest}} in the {{ApplicationSubmissionContext}}.  The 
> current behavior is to either build one from {{getResource}} or directly from 
> {{getAMContainerResourceRequest}}, depending on if 
> {{getAMContainerResourceRequest}} is null or not.  We'll need to add a third 
> method, say {{getAMContainerResourceRequests}}, which takes a list of 
> {{ResourceRequest}} so that clients can specify the multiple resource 
> requests.
> # There are some places where things are hardcoded to overwrite what the 
> client specifies.  These are pretty straightforward to fix.



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

---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to