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https://issues.apache.org/jira/browse/FLINK-23893?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17402096#comment-17402096
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Yangze Guo commented on FLINK-23893:
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A slot request contains multiple dimensions resources. So, it is indeed a
multi-dimensional packing problem, which is NP-hard. I agree that we should
document it and maybe find another suboptimal strategy in the future.
> Fine-grained resource allocation may fail depending on slot allocation order
> ----------------------------------------------------------------------------
>
> Key: FLINK-23893
> URL: https://issues.apache.org/jira/browse/FLINK-23893
> Project: Flink
> Issue Type: Bug
> Components: Runtime / Coordination
> Reporter: Chesnay Schepler
> Priority: Minor
> Fix For: 1.14.0
>
>
> The fine-grained slot management is relatively simple in that it iterates
> over each registered TM in order for each required slot.
> This means that you can pretty easily create scenarios where, depending on
> the slot order, the allocation of a slot may fail.
> A trivial example, only using memory for conciseness:
> 2 TMs with 3 MB of memory each
> 2 slot-sharing groups with parallelism=2 and the following requirements:
> 1) 1 MB memory
> 2) 2 MB memory
> If both sub-tasks of 1) are scheduled first on a single TM then the job
> cannot be scheduled.
> It's not terrible for this limitation to exist in the first version, but it
> should be _explicitly_ documented.
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