Hi Martin,
Could you please remind what was the conclusion of discussion on
upgrading Scala to 2.12.15/16?
https://lists.apache.org/thread/hwksnsqyg7n3djymo7m1s7loymxxbc3t - I
couldn't find any follow-up vote?
If it's acceptable to break binary compatibility by such an upgrade,
then upgrading to JDK17 before 2.0 will be doable?
thanks,
maciek
On 04.10.2022 18:21, Martijn Visser wrote:
Hi Yaroslav,
Thanks for the feedback, that's much appreciated! Regarding Java 17 as
a prerequisite, we would have to break compatibility already since
Scala 2.12.7 doesn't compile on Java 17 [1].
Given that we can only remove Scala APIs with the next major Flink
(2.0) version, would that still impact you a lot? I do imagine that if
we get to a Flink 2.0 version there would be more breaking involved
anyway. The biggest consequence of deprecating support for Scala in
Flink 1.x would be that new APIs would only be available in Java, but
since these don't exist yet there would be no refactoring involved. I
can imagine that we might change something in an existing API, but
that would have certain compatibility guarantees already (depending if
it's Public/PublicEvolving/Experimental). If a change would happen
there, I think it would be smaller refactoring.
Best regards,
Martijn
[1] https://issues.apache.org/jira/browse/FLINK-25000
On Tue, Oct 4, 2022 at 10:58 AM Yaroslav Tkachenko
<yaros...@goldsky.com> wrote:
Hi Martijn,
As a Scala user, this change would affect me a lot and I'm not
looking forward to rewriting my codebase, and it's not even a very
large one :)
I'd like to suggest supporting Java 17 as a prerequisite
(https://issues.apache.org/jira/browse/FLINK-15736). Things like
switch expressions and records could simplify the migration
quite a bit. Would you consider adding it to the FLIP?
On Tue, Oct 4, 2022 at 10:50 AM Jing Ge <j...@ververica.com> wrote:
Hi Martijn,
Thanks for bringing this up. It is generally a great idea, so +1.
Since both scala extension projects mentioned in the FLIP are
still very young and I don't think they will attract more
scala developers as Flink could just because they are external
projects. It will be a big issue for users who have to rewrite
their large codebases. Those users should be aware of the
effort from now on and would better not count on those scala
extension projects and prepare their migration plan
before Flink 2.0.
Best regards,
Jing
On Tue, Oct 4, 2022 at 1:59 PM Martijn Visser
<martijnvis...@apache.org> wrote:
Hi Marton,
You're making a good point, I originally wanted to include
already the User mailing list to get their feedback but
forgot to do so. I'll do some more outreach via other
channels as well.
@Users of Flink, I've made a proposal to deprecate and
remove Scala API support in a future version of Flink.
Your feedback on this topic is very much appreciated.
Regarding the large Scala codebase for Flink, a potential
alternative could be to have a wrapper for all Java APIs
that makes them available as Scala APIs. However, this
still requires Scala maintainers and I don't think that we
currently have those in our community. The easiest
solution for them would be to use the Java APIs directly.
Yes it would involve work, but we won't actually be able
to remove the Scala APIs until Flink 2.0 so there's still
time for that :)
Best regards,
Martijn
On Tue, Oct 4, 2022 at 1:26 AM Márton Balassi
<balassi.mar...@gmail.com> wrote:
Hi Martjin,
Thanks for compiling the FLIP. I agree with the
sentiment that Scala poses
considerable maintenance overhead and key improvements
(like 2.13 or 2.12.8
supports) are hanging stale. With that said before we
make this move we
should attempt to understand the userbase affected.
A quick Slack and user mailing list search does return
quite a bit of
results for scala (admittedly a cursory look at them
suggest that many of
them have to do with missing features in Scala that
exist in Java or Scala
versions). I would love to see some polls on this
topic, we could also use
the Flink twitter handle to ask the community about this.
I am aware of users having large existing Scala
codebases for Flink. This
move would pose a very large effort on them, as they
would need to rewrite
much of their existing code. What are the alternatives
in your opinion,
Martjin?
On Tue, Oct 4, 2022 at 6:22 AM Martijn Visser
<martijnvis...@apache.org>
wrote:
> Hi everyone,
>
> I would like to open a discussion thread on FLIP-265
Deprecate and remove
> Scala API support. Please take a look at
>
>
https://cwiki.apache.org/confluence/display/FLINK/FLIP-265+Deprecate+and+remove+Scala+API+support
> and provide your feedback.
>
> Best regards,
>
> Martijn
> https://twitter.com/MartijnVisser82
> https://github.com/MartijnVisser
>
