given the issues with scala 2.10 and java 8 i am in favor of dropping scala 2.10 in next release
On Sat, Feb 25, 2017 at 2:10 PM, Sean Owen <so...@cloudera.com> wrote: > I want to bring up the issue of Scala 2.10 support again, to see how > people feel about it. Key opinions from the previous responses, I think: > > Cody: only drop 2.10 support when 2.12 support is added > Koert: we need all dependencies to support 2.12; Scala updates are pretty > transparent to IT/ops > Ofir: make sure to deprecate 2.10 in Spark 2.1 > Reynold: let’s maybe remove support for Scala 2.10 and Java 7 in Spark 2.2 > Matei: let’s not remove things unless they’re burdensome for the project; > some people are still on old environments that their IT can’t easily update > > Scala 2.10 support was deprecated in 2.1, and we did remove Java 7 support > for 2.2. https://issues.apache.org/jira/browse/SPARK-14220 tracks the > work to support 2.12, and there is progress, especially in dependencies > supporting 2.12. > > It looks like 2.12 support may even entail a breaking change as documented > in https://issues.apache.org/jira/browse/SPARK-14643 and will mean > dropping Kafka 0.8, for example. In any event it’s going to take some > surgery and a few hacks to make one code base work across 2.11 and 2.12. I > don’t see this happening for Spark 2.2.0 because there are just a few weeks > left. > > Supporting three versions at once is probably infeasible, so dropping 2.10 > should precede 2.12 support. Right now, I would like to make progress > towards changes that 2.12 will require but that 2.11/2.10 can support. For > example, we have to update scalatest, breeze, chill, etc. and can do that > before 2.12 is enabled. However I’m finding making those changes tricky or > maybe impossible in one case while 2.10 is still supported. > > For 2.2.0, I’m wondering if it makes sense to go ahead and drop 2.10 > support, and even get in additional prep work for 2.12, into the 2.2.0 > release. The move to support 2.12 in 2.3.0 would then be a smaller change. > It isn’t strictly necessary. We could delay all of that until after 2.2.0 > and get it all done between 2.2.0 and 2.3.0. But I wonder if 2.10 is legacy > enough at this stage to drop for Spark 2.2.0? > > I don’t feel strongly about it but there are some reasonable arguments for > dropping it: > > - 2.10 doesn’t technically support Java 8, though we do have it working > still even after requiring Java 8 > - Safe to say virtually all common _2.10 libraries has a _2.11 counterpart > at this point? > - 2.10.x was “EOL” in September 2015 with the final 2.10.6 release > - For a vendor viewpoint: CDH only supports Scala 2.11 with Spark 2.x > > Before I open a JIRA, just soliciting opinions. > > > On Tue, Oct 25, 2016 at 4:36 PM Sean Owen <so...@cloudera.com> wrote: > >> I'd like to gauge where people stand on the issue of dropping support for >> a few things that were considered for 2.0. >> >> First: Scala 2.10. We've seen a number of build breakages this week >> because the PR builder only tests 2.11. No big deal at this stage, but, it >> did cause me to wonder whether it's time to plan to drop 2.10 support, >> especially with 2.12 coming soon. >> >> Next, Java 7. It's reasonably old and out of public updates at this >> stage. It's not that painful to keep supporting, to be honest. It would >> simplify some bits of code, some scripts, some testing. >> >> Hadoop versions: I think the the general argument is that most anyone >> would be using, at the least, 2.6, and it would simplify some code that has >> to reflect to use not-even-that-new APIs. It would remove some moderate >> complexity in the build. >> >> >> "When" is a tricky question. Although it's a little aggressive for minor >> releases, I think these will all happen before 3.x regardless. 2.1.0 is not >> out of the question, though coming soon. What about ... 2.2.0? >> >> >> Although I tend to favor dropping support, I'm mostly asking for current >> opinions. >> >
