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Posted to user@flink.apache.org by M Singh <ma...@yahoo.com> on 2019/07/14 13:07:27 UTC

Apache Flink - Manipulating the state of an object in an evictor or trigger

Hi:
Is it safe to manipulate the state of an object in the evictor or trigger ?  Are there any best practices/dos and don't on this ?
Thanks

Re: Apache Flink - Manipulating the state of an object in an evictor or trigger

Posted by taher koitawala <ta...@gmail.com>.
As far as I know. It is completely safe

On Fri, Jul 19, 2019, 1:35 AM M Singh <ma...@yahoo.com> wrote:

> Just wanted to see if there is any advice on this question.  Thanks
>
> On Sunday, July 14, 2019, 09:07:45 AM EDT, M Singh <ma...@yahoo.com>
> wrote:
>
>
> Hi:
>
> Is it safe to manipulate the state of an object in the evictor or trigger
> ?  Are there any best practices/dos and don't on this ?
>
> Thanks
>

Re: Apache Flink - Manipulating the state of an object in an evictor or trigger

Posted by M Singh <ma...@yahoo.com>.
 Just wanted to see if there is any advice on this question.  Thanks
    On Sunday, July 14, 2019, 09:07:45 AM EDT, M Singh <ma...@yahoo.com> wrote:  
 
 Hi:
Is it safe to manipulate the state of an object in the evictor or trigger ?  Are there any best practices/dos and don't on this ?
Thanks

Re: Apache Flink - Manipulating the state of an object in an evictor or trigger

Posted by M Singh <ma...@yahoo.com>.
 Biao:
I am asking this question, just to understand the impact and best practices around it.  The state I am referring to it the objects that are passed to evictor.
https://ci.apache.org/projects/flink/flink-docs-stable/dev/stream/operators/windows.html#evictors

void evictBefore(Iterable<TimestampedValue<T>> elements, int size, W window, EvictorContext evictorContext);
And you are right, I also don't see this in this information in the docs.  That is the reason I wanted to find out.
Thanks again for your time.
Mans  
    On Friday, July 19, 2019, 02:15:02 AM EDT, Biao Liu <mm...@gmail.com> wrote:  
 
 Hi,
I don't find any official document about it.
There are several state relevant methods in `TriggerContext`. I believe it's absolutely safe to use state in `Trigger` through `TriggerContext`.
Regarding to `Evictor`, there is no such methods in `EvictorContext`. After taking a glance on relevant codes, I guess it's OK for now. But I suggest do not manipulate state in `Evictor` until there is an official guarantee.
BTW, I'm just wondering why do you want to manipulate state in `Evictor`? If your requirement is reasonable, maybe we could support it officially.

M Singh <ma...@yahoo.com> 于2019年7月14日周日 下午9:07写道：

Hi:
Is it safe to manipulate the state of an object in the evictor or trigger ?  Are there any best practices/dos and don't on this ?
Thanks

Re: Apache Flink - Manipulating the state of an object in an evictor or trigger

Posted by Biao Liu <mm...@gmail.com>.
Hi,

I don't find any official document about it.

There are several state relevant methods in `TriggerContext`. I believe
it's absolutely safe to use state in `Trigger` through `TriggerContext`.

Regarding to `Evictor`, there is no such methods in `EvictorContext`. After
taking a glance on relevant codes, I guess it's OK for now. But I suggest
do not manipulate state in `Evictor` until there is an official guarantee.

BTW, I'm just wondering why do you want to manipulate state in `Evictor`?
If your requirement is reasonable, maybe we could support it officially.


M Singh <ma...@yahoo.com> 于2019年7月14日周日 下午9:07写道：

> Hi:
>
> Is it safe to manipulate the state of an object in the evictor or trigger
> ?  Are there any best practices/dos and don't on this ?
>
> Thanks
>