flink-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Robert Metzger <rmetz...@apache.org>
Subject Re: Replacing Checkpointed interface with field annotations
Date Wed, 01 Jul 2015 08:14:00 GMT
I would certainly not replace the current Checkpointed interface by this
implementation.
The interface allows you to perform custom actions when creating a snapshot
or restoring state.

We could add the annotation variant for simple cases like in your example.


On Wed, Jul 1, 2015 at 10:10 AM, Maximilian Michels <mxm@apache.org> wrote:

> Hi Gyula,
>
> Looks like a neat feature you thought of; I like it. One problem I see is
> that with all the big changes and discussions in streaming, I wonder if we
> should get other things right first. Another problem could be the lack of
> clarity of this implementation. State annotations can now be very easily
> placed anywhere in a class with the @Annotation. The Checkpointed interface
> we have now is more explicit. From an end user perspective it might make
> sense to use annotations, from a developer perspective I'm not sure.
>
> Cheers,
> Max
>
>
>
> On Tue, Jun 30, 2015 at 1:44 PM, Hermann Gábor <reckoner42@gmail.com>
> wrote:
>
> > Wow, this looks pretty concise. I really like it!
> >
> > On Mon, Jun 29, 2015 at 3:27 PM Gyula Fóra <gyfora@apache.org> wrote:
> >
> > > Hey all!
> > >
> > > Just to add something new to the end of the discussion list. After some
> > > discussion with Seif, and Paris, I have added a commit that replaces
> the
> > > use of the Checkpointed interface with field annotations.
> > >
> > > This is probably the most lightweight state declaration so far and it
> > will
> > > probably work very well to replace the Checkpointed interface:
> > >
> > > public class StatefulMapper implements MapFunction<Integer,Integer> {
> > >
> > > @State
> > > int counter;
> > > @State
> > > Serializable state;
> > >
> > > Object notState
> > >
> > > public Integer map(Integer input)[
> > > counter++;
> > > //update other state
> > > /...
> > > }
> > > }
> > >
> > > What do you think?
> > > You can check it out here
> > > <https://github.com/gyfora/flink/commits/annotated_state>.
> > >
> > > Cheers,
> > > Gyula
> > >
> >
>

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message