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https://issues.apache.org/jira/browse/SAMZA-334?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14063684#comment-14063684
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Chris Riccomini commented on SAMZA-334:
---------------------------------------

bq. I am not sure what guarantees provides YARN for one to choose the machine 
where a new scaled out Task will run.

Unfortunately, YARN is pretty bad at this right now (See SAMZA-335 for 
discussion). We run the FairShare scheduler internally, which is a bit better, 
since it tries to evenly distribute (round robin) containers among all nodes on 
the grid. Still, it's not perfect.

> Need for asymmetric container config
> ------------------------------------
>
>                 Key: SAMZA-334
>                 URL: https://issues.apache.org/jira/browse/SAMZA-334
>             Project: Samza
>          Issue Type: Improvement
>          Components: container
>    Affects Versions: 0.8.0
>            Reporter: Chinmay Soman
>
> The current (and upcoming) partitioning scheme(s) suggest that there might be 
> a skew in the amount of data ingested and computation performed across 
> different containers for a given Samza job. This directly affects the amount 
> of resources required by a container - which today are completely symmetric.
> Case A] Partitioning on Kafka partitions
> For instance, consider a partitioner job which reads data from different 
> Kafka topics (having different partition layouts). In this case, its possible 
> that a lot of topics have a smaller number of Kafka partitions. Consequently 
> the containers processing these partitions would need more resources than 
> those responsible for the higher numbered partitions. 
> Case B] Partitioning based on Kafka topics
> Even in this case, its very easy for some containers to be doing more work 
> than others - leading to a skew in resource requirements.
> Today, the container config is based on the requirements for the worst (doing 
> the most work) container. Needless to say, this leads to resource wastage. A 
> better approach needs to consider what is the true requirement per container 
> (instead of per job).



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