Type names: I vote for option 2. The user must explicitly add a dependency to this library and the wrapper types are in a different package. It seems reasonable to expect them to do an import rename if there's a need to drop down to the Java API.
Test Utils: The test utils in kafka-streams-scala are nice and lean, but I'm not sure if it provides much more value than other options that exist in the community. There's an embedded Kafka/ZK project implementation for ScalaTest that's popular and active: manub/scalatest-embedded-kakfa. It implies you must also use ScalaTest, which I acknowledge isn't everyone's first choice for Scala test framework, but it probably is one of, if not the most, popular library. It includes a DSL for Kafka Streams too. If this KIP is accepted then perhaps a PR to that project could be made to support the new wrapper implementations. https://github.com/manub/scalatest-embedded-kafka#scalatest-embedded-kafka-streams Sean On Sun, Mar 18, 2018 at 4:05 AM, Debasish Ghosh < debasish.gh...@lightbend.com> wrote: > > > > > Should this be 1.2 (maybe it's even better to not put any version at > > all) > > > Actually wanted to emphasize that the support is from 1.0.0 onwards .. > Should we make that explicit ? Like .. > > kafka-streams-scala only depends on the Scala standard library and Kafka > > Streams 1.0.0+. > > > In 1.1 release, we add a new module `kafka-streams-test-utils` to simplify > > testing for Kafka Streams applications. Are those test utils suitable for > > Scala users or should we add Scala wrappers for those, too? > > > I will check up and let you know .. > > Also I am not clear about the decision on renaming of Scala abstractions. > Can we have a consensus on this ? Here's the summary .. > > *Option 1:* Keep names separate (KStream for Java class, KStreamS for > Scala). No renaming of imports required. > *Option 2:* Unify names (KStream for Java and Scala class names). No > conflict since they will reside in different packages. But if we need to > use both abstractions, renaming of imports are required. But again, this > may not be a too frequent use case. > > Suggestions ? > > regards. > > On Sat, Mar 17, 2018 at 3:07 AM, Matthias J. Sax <matth...@confluent.io> > wrote: > > > Thanks a lot for the KIP! Two questions: > > > > 1) the KIP states: > > > > > kafka-streams-scala only depends on the Scala standard library and > Kafka > > Streams 1.0.0. > > > > Should this be 1.2 (maybe it's even better to not put any version at > all) > > > > > > 2) In 1.1 release, we add a new module `kafka-streams-test-utils` to > > simplify testing for Kafka Streams applications. Are those test utils > > suitable for Scala users or should we add Scala wrappers for those, too? > > > > > > -Matthias > > > > > > On 3/16/18 11:10 AM, Ted Yu wrote: > > > Import renames seem to be fine. > > > > > > The class names with trailing 'S' look clean. > > > > > > Cheers > > > > > > On Fri, Mar 16, 2018 at 11:04 AM, Ismael Juma <ism...@juma.me.uk> > wrote: > > > > > >> If this is rare (as it sounds), relying on import renames seems fine > to > > me. > > >> Let's see what others think. > > >> > > >> Ismael > > >> > > >> On Fri, Mar 16, 2018 at 10:51 AM, Debasish Ghosh < > > >> debasish.gh...@lightbend.com> wrote: > > >> > > >>> I am not sure if this is practical or not. But theoretically a user > may > > >>> want to extract the unsafe Java abstraction from the Scala ones and > use > > >>> Java APIs on them .. e.g. > > >>> > > >>> val userClicksStream: KStreamS[String, Long] = > > >>> builder.stream(userClicksTopic) // Scala abstraction > > >>> > > >>> val jStream: KStream[String, Long] = userClicksStream.inner // > > publishes > > >>> the underlying Java abstraction > > >>> > > >>> //.. work with Java, may be pass to some function written in Java > > >>> > > >>> I do realize this is somewhat of a convoluted use case and may not be > > >>> practically useful .. > > >>> > > >>> Otherwise we can very well work on the suggested approach of unifying > > the > > >>> names .. > > >>> > > >>> regards. > > >>> > > >>> > > >>> > > >>> On Fri, Mar 16, 2018 at 10:28 PM, Ismael Juma <ism...@juma.me.uk> > > wrote: > > >>> > > >>>> What does "mixed mode application" mean? What are the cases where a > > >> user > > >>>> would want to use both APIs? I think that would help understand the > > >>>> reasoning. > > >>>> > > >>>> Thanks, > > >>>> Ismael > > >>>> > > >>>> On Fri, Mar 16, 2018 at 8:48 AM, Debasish Ghosh < > > >>>> debasish.gh...@lightbend.com> wrote: > > >>>> > > >>>>> Hi Damian - > > >>>>> > > >>>>> We could. But in case the user wants to use both Scala and Java > APIs > > >>> (may > > >>>>> be for some mixed mode application), won't that be confusing ? She > > >> will > > >>>>> have to do something like .. > > >>>>> > > >>>>> import o.a.k.s.scala.{KStream => KStreamS} > > >>>>> > > >>>>> to rename Scala imports or the other way round for imported Java > > >>> classes. > > >>>>> > > >>>>> regards. > > >>>>> > > >>>>> > > >>>>> > > >>>>> On Fri, Mar 16, 2018 at 9:07 PM, Damian Guy <damian....@gmail.com> > > >>>> wrote: > > >>>>> > > >>>>>> Hi Debasish, > > >>>>>> > > >>>>>> Thanks for the KIP - will be a great addition to streams. I've > only > > >>>> had a > > >>>>>> quick scan, but seeing as the Scala classes are going to be in > > >> their > > >>>> own > > >>>>>> package could we drop the S at the end of the class names? > > >>>>>> > > >>>>>> Thanks, > > >>>>>> Damian > > >>>>>> > > >>>>>> > > >>>>>> On Fri, 16 Mar 2018 at 15:25 Debasish Ghosh < > > >>>>> debasish.gh...@lightbend.com> > > >>>>>> wrote: > > >>>>>> > > >>>>>>> Hi - > > >>>>>>> > > >>>>>>> A new KIP, KIP-270 is up for discussion: > > >>>>>>> > > >>>>>>> https://cwiki.apache.org/confluence/display/KAFKA/KIP- > > >>>>>> 270+-+A+Scala+Wrapper+Library+for+Kafka+Streams > > >>>>>>> > > >>>>>>> The relevant JIRA issue: https://issues.apache.org/ > > >>>>>> jira/browse/KAFKA-6670 > > >>>>>>> > > >>>>>>> The library as proposed in the KIP has been implemented at > > >>>>>>> https://github.com/lightbend/kafka-streams-scala and the current > > >>>>> release > > >>>>>>> is > > >>>>>>> 0.2.0 ( > > >>>>>>> https://github.com/lightbend/kafka-streams-scala/releases/ > > >>> tag/v0.2.0 > > >>>> ). > > >>>>>>> We at Lightbend has been using it since quite some time now. > > >>>>>>> > > >>>>>>> regards. > > >>>>>>> > > >>>>>>> -- > > >>>>>>> Debasish Ghosh > > >>>>>>> Principal Engineer > > >>>>>>> > > >>>>>>> Twitter: @debasishg > > >>>>>>> Blog: http://debasishg.blogspot.com > > >>>>>>> Code: https://github.com/debasishg > > >>>>>>> > > >>>>>> > > >>>>> > > >>>>> > > >>>>> > > >>>>> -- > > >>>>> Debasish Ghosh > > >>>>> Principal Engineer > > >>>>> > > >>>>> Twitter: @debasishg > > >>>>> Blog: http://debasishg.blogspot.com > > >>>>> Code: https://github.com/debasishg > > >>>>> > > >>>> > > >>> > > >>> > > >>> > > >>> -- > > >>> Debasish Ghosh > > >>> Principal Engineer > > >>> > > >>> Twitter: @debasishg > > >>> Blog: http://debasishg.blogspot.com > > >>> Code: https://github.com/debasishg > > >>> > > >> > > > > > > > > > > -- > Debasish Ghosh > Principal Engineer > > Twitter: @debasishg > Blog: http://debasishg.blogspot.com > Code: https://github.com/debasishg > -- Senior Software Engineer, Lightbend, Inc. <http://lightbend.com> @seg1o <https://twitter.com/seg1o>, in/seanaglover <https://www.linkedin.com/in/seanaglover/>
