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https://issues.apache.org/jira/browse/FLINK-35035?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17835564#comment-17835564
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yuanfenghu commented on FLINK-35035:
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[~echauchot]
Thank you for your reply, but I have some questions:
jobmanager.adaptive-scheduler.min-parallelism-increase is a parameter on
jobmanager, so I cannot update this value after the task is started. Assuming
it is set to 5, this time it causes some problems:
The original task is [v1 (maxp=10 minp = 1)] -> [v2 (maxp=10, minp=1)]. If I
call restapi, the parallelism is overwritten to the new [v1 (maxp=12 minp = 1)]
-> [v2 (maxp=12, minp=1)], then I added slots to the cluster, but obviously I
only need to add 2 slots to meet the requirements, but because
min-parallelism-increase was not reached, So this will not cause the task to
trigger expansion. It needs to wait until scaling-interval.max is reached
before triggering (scaling-interval.max needs to be set first). I think in this
case, should I add a configuration item to support its triggering?
> 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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