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https://issues.apache.org/jira/browse/FLINK-15325?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17000886#comment-17000886
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Till Rohrmann commented on FLINK-15325:
---------------------------------------

If there is a good need for this feature, then one could introduce such a 
config option. I assume this would pretty much be a power user feature as I 
don't see our regular users to change it.

How exactly would this config option affect the normal scheduling and the 
spread out strategy? Simply setting the collection of input preferences to 
{{empty}}?

> Input location preference which affects task distribution may make certain 
> job performance worse 
> -------------------------------------------------------------------------------------------------
>
>                 Key: FLINK-15325
>                 URL: https://issues.apache.org/jira/browse/FLINK-15325
>             Project: Flink
>          Issue Type: Improvement
>          Components: Runtime / Coordination
>    Affects Versions: 1.10.0
>            Reporter: Zhu Zhu
>            Priority: Major
>         Attachments: D58ADB03-7187-46B1-B077-91E5005FD463.png
>
>
> When running TPC-DS jobs in a session cluster, we observed that sometimes 
> tasks are not evenly distributed in TMs. The root cause turned out to be that 
> the downstream tasks tend to be TM or host local with its input tasks. This 
> helps to reduce network shuffle. 
> However, in certain cases, like the topology presented in the attached image, 
> jamming the input task's TM and machine with downstream tasks would affect 
> the performance. In this case, respecting input location preferences is 
> causing troubles more than bringing benefits.
> So I'm wondering whether we should introduce a config so that users can 
> disable input location preferences?



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