[jira] [Assigned] (FLINK-14594) Fix matching logics of ResourceSpec/ResourceProfile/Resource considering double values

["Till Rohrmann (Jira)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/FLINK-14594?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Till Rohrmann reassigned FLINK-14594:
-------------------------------------

    Assignee: Zhu Zhu

> Fix matching logics of ResourceSpec/ResourceProfile/Resource considering double values
> --------------------------------------------------------------------------------------
>
>                 Key: FLINK-14594
>                 URL: https://issues.apache.org/jira/browse/FLINK-14594
>             Project: Flink
>          Issue Type: Sub-task
>          Components: Runtime / Coordination
>    Affects Versions: 1.10.0
>            Reporter: Zhu Zhu
>            Assignee: Zhu Zhu
>            Priority: Major
>             Fix For: 1.10.0
>
>
> There are resources of double type values, like cpuCores in ResourceSpec/ResourceProfiles or all extended resources. These values can be generated via a merge or subtract, so that there can be small deltas.
> Currently, in resource matching, these resources are matched without considering the deltas, which may result in issues as below:
> 1. A shared slot cannot fulfill a slot request even if it should be able to (because it is possible that {{(d1 + d2) - d1 < d2}} for double values)
> 2. if a shared slot is used up, an unexpected error may occur when calculating its remaining resources in SlotSharingManager#listResolvedRootSlotInfo -> ResourceProfile#subtract
> 3. an unexpected error may happen when releasing a single task slot from a shared slot (in ResourceProfile#subtract)
> To solve this issue, I'd propose to:
> 1.  Introduce a ResourceValue which stores a double value and its acceptable precision (the same kind of resource should use the same precision). It provides {{compareTo}} method, in which two ResourceValues are considered equal if the subtracted abs does not exceed the precision. It also provides merge/subtract/validation operations.
> 2. ResourceSpec/ResourceProfile uses ResourceValue for cpuCores and fix related logics(ctor/validation/subtract/matching). The usages of {{equals}} should be replaced with another method {{hasSameResources}} which considers the precision.
> 3. Resource uses ResourceValue to store its value. Also fix related logics.
> cc [~trohrmann] [~azagrebin] [~xintongsong]



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