[
https://issues.apache.org/jira/browse/FLINK-15959?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17039149#comment-17039149
]
YufeiLiu commented on FLINK-15959:
----------------------------------
[~xintongsong] Hi, I've got a problem and I need some advice.
How should I deal with when job have restarted because of TaskExecutors has
lost, seems like have to block the scheduling thread until cluster has been
recovered, otherwise scheduler will use slots from SlotPool until available
slots are empty, this also can cause load balance issue.
I feel like have a wrong direction, maybe shoule implement it in scheduler,
allocate enough resource before execution scheduling.
> Add min/max number of slots configuration to limit total number of slots
> ------------------------------------------------------------------------
>
> Key: FLINK-15959
> URL: https://issues.apache.org/jira/browse/FLINK-15959
> Project: Flink
> Issue Type: Improvement
> Components: Runtime / Coordination
> Affects Versions: 1.11.0
> Reporter: YufeiLiu
> Priority: Major
>
> Flink removed `-n` option after FLIP-6, change to ResourceManager start a new
> worker when required. But I think maintain a certain amount of slots is
> necessary. These workers will start immediately when ResourceManager starts
> and would not release even if all slots are free.
> Here are some resons:
> # Users actually know how many resources are needed when run a single job,
> initialize all workers when cluster starts can speed up startup process.
> # Job schedule in topology order, next operator won't schedule until prior
> execution slot allocated. The TaskExecutors will start in several batchs in
> some cases, it might slow down the startup speed.
> # Flink support
> [FLINK-12122|https://issues.apache.org/jira/browse/FLINK-12122] [Spread out
> tasks evenly across all available registered TaskManagers], but it will only
> effect if all TMs are registered. Start all TMs at begining can slove this
> problem.
> *suggestion:*
> * Add config "taskmanager.minimum.numberOfTotalSlots" and
> "taskmanager.maximum.numberOfTotalSlots", default behavior is still like
> before.
> * Start plenty number of workers to satisfy minimum slots when
> ResourceManager accept leadership(subtract recovered workers).
> * Don't comlete slot request until minimum number of slots are registered,
> and throw exeception when exceed maximum.
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
