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Posted to user@flink.apache.org by 杨浩 <ya...@163.com> on 2021/12/20 08:27:53 UTC

回复:Re: Will Flink loss some old Keyed State when changing the parallelism



Thanks for your replay. If we don't set the max parallelism, and we change the parallelism to a very big num, will the state loss?











At 2021-11-27 01:20:49, "Yun Tang" <ta...@apache.org> wrote:
>Hi Yang,
>
>Flink keeps the max key groups the same no matter how parallelism changes, and use this to avoid state data lost [1]
>
>[1] https://flink.apache.org/features/2017/07/04/flink-rescalable-state.html
>
>
>Best
>Yun Tang
>
>On 2021/11/26 10:07:29 Nicolaus Weidner wrote:
>> Hi,
>> 
>> to rescale, you should take a savepoint, stop the job, then restart from
>> the savepoint with your new desired parallelism. This way, no data will be
>> lost.
>> 
>> Best,
>> Nico
>> 
>> On Thu, Nov 25, 2021 at 10:53 AM 杨浩 <ya...@163.com> wrote:
>> 
>> > Will Flink loss some old Keyed State when changing the parallelism, like 2
>> > -> 5, or 5->3?
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>>

Re: Re: Will Flink loss some old Keyed State when changing the parallelism

Posted by Seth Wiesman <sj...@gmail.com>.
No. The default max parallelism of 128 will be applied. If you try to
restore above that value, the restore will fail and you can simply restore
at a smaller value.

No data loss.

On Mon, Dec 20, 2021 at 2:28 AM 杨浩 <ya...@163.com> wrote:

>
> Thanks for your replay. If we don't set the max parallelism, and we change
> the parallelism to a very big num, will the state loss?
>
>
>
>
>
> At 2021-11-27 01:20:49, "Yun Tang" <ta...@apache.org> wrote:
> >Hi Yang,
> >
> >Flink keeps the max key groups the same no matter how parallelism changes, and use this to avoid state data lost [1]
> >
> >[1] https://flink.apache.org/features/2017/07/04/flink-rescalable-state.html
> >
> >
> >Best
> >Yun Tang
> >
> >On 2021/11/26 10:07:29 Nicolaus Weidner wrote:
> >> Hi,
> >>
> >> to rescale, you should take a savepoint, stop the job, then restart from
> >> the savepoint with your new desired parallelism. This way, no data will be
> >> lost.
> >>
> >> Best,
> >> Nico
> >>
> >> On Thu, Nov 25, 2021 at 10:53 AM 杨浩 <ya...@163.com> wrote:
> >>
> >> > Will Flink loss some old Keyed State when changing the parallelism, like 2
> >> > -> 5, or 5->3?
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >>
>
>
>
>
>