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https://issues.apache.org/jira/browse/FLINK-35035?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17836462#comment-17836462
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Etienne Chauchot commented on FLINK-35035:
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with adaptive scheduler, the jobMaster declares resources needed with a min and
a max. The only difference with reactive mode is that the max is +INF. Here we
are talking about declaring min resources needed. So unless there is something
I missed, I'm not sure reactive mode is relevant here.
If I understand correctly, what you want in the end is to use whatever new
slots arrive in the cluster with a minimal waiting period. So why not just
leave default min-parallelism-increase=1, leave default scaling-interval.max
unset and change default scaling-interval.min of 30s to 0s ?
The only thing is that you will have more frequent rescales (each time a slot
is added to the cluster) modulo slots that are added during the stabilization
period that do not lead to a rescale.
> Reduce job pause time when cluster resources are expanded in adaptive mode
> --------------------------------------------------------------------------
>
> Key: FLINK-35035
> URL: https://issues.apache.org/jira/browse/FLINK-35035
> Project: Flink
> Issue Type: Improvement
> Components: Runtime / Task
> Affects Versions: 1.19.0
> Reporter: yuanfenghu
> Priority: Minor
>
> When 'jobmanager.scheduler = adaptive' , job graph changes triggered by
> cluster expansion will cause long-term task stagnation. We should reduce this
> impact.
> As an example:
> I have jobgraph for : [v1 (maxp=10 minp = 1)] -> [v2 (maxp=10, minp=1)]
> When my cluster has 5 slots, the job will be executed as [v1 p5]->[v2 p5]
> When I add slots the task will trigger jobgraph changes，by
> org.apache.flink.runtime.scheduler.adaptive.ResourceListener#onNewResourcesAvailable，
> However, the five new slots I added were not discovered at the same time (for
> convenience, I assume that a taskmanager has one slot), because no matter
> what environment we add, we cannot guarantee that the new slots will be added
> at once, so this will cause onNewResourcesAvailable triggers repeatedly
> ，If each new slot action has a certain interval, then the jobgraph will
> continue to change during this period. What I hope is that there will be a
> stable time to configure the cluster resources and then go to it after the
> number of cluster slots has been stable for a certain period of time. Trigger
> jobgraph changes to avoid this situation
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