Certainly, Scala 2.12 support precedes Java 9 support. A lot of the work is in place already, and the last issue is dealing with how Scala closures are now implemented quite different with lambdas / invokedynamic. This affects the ClosureCleaner. For the interested, this is as far as I know the main remaining issue:
Despite the odd naming, all of these versions of Java are successors to Java 9. Supporting any of them is probably the same thing, so, the work is still for now getting it working on Java 9. Whereas Java has been very backwards-compatible in the past, the new module structure is almost certain to break something in Spark or its dependencies. Removing JAXB from the JDK alone causes issues. Getting it to run at all on Java 9 may require changes, whereas compatibility with new Java major releases in the past generally came for free. It'll be worth trying to make that happen soonish. I'm guessing for Spark 3.x in first half of next year? But, first things first. Scala 2.12 support. On Fri, Oct 27, 2017 at 6:02 PM Jörn Franke <jornfra...@gmail.com> wrote: > Scala 2.12 is not yet supported on Spark - this means also not JDK9: > https://issues.apache.org/jira/plugins/servlet/mobile#issue/SPARK-14220 > > If you look at the Oracle support then jdk 9 is anyway only supported for > 6 months. JDK 8 is Lts (5 years) JDK 18.3 will be only 6 months and JDK > 18.9 is lts (5 years). > http://www.oracle.com/technetwork/java/eol-135779.html > > I do not think Spark should support non-lts releases. Especially for JDK9 > I do not see a strong technical need, but maybe I am overlooking something. > Of course http2 etc would be nice for the web interfaces, but currently not > very urgent. > > On 27. Oct 2017, at 04:44, Zhang, Liyun <liyun.zh...@intel.com> wrote: > > Thanks your suggestion, seems that scala 2.12.4 support jdk9 > > > > Scala 2.12.4 <https://github.com/scala/scala/releases/tag/v2.12.4> is now > available. > > Our benchmarks > <https://scala-ci.typesafe.com/grafana/dashboard/db/scala-benchmark?var-branch=2.12.x&from=1501580691158&to=1507711932006> > show > a further reduction in compile times since 2.12.3 of 5-10%. > > Improved Java 9 friendliness, with more to come! > > > > Best Regards > > Kelly Zhang/Zhang,Liyun > > > > > > > > > > > > *From:* Reynold Xin [mailto:r...@databricks.com <r...@databricks.com>] > *Sent:* Friday, October 27, 2017 10:26 AM > *To:* Zhang, Liyun <liyun.zh...@intel.com>; d...@spark.apache.org; > user@spark.apache.org > *Subject:* Re: Anyone knows how to build and spark on jdk9? > > > > It probably depends on the Scala version we use in Spark supporting Java 9 > first. > > > > On Thu, Oct 26, 2017 at 7:22 PM Zhang, Liyun <liyun.zh...@intel.com> > wrote: > > Hi all: > > 1. I want to build spark on jdk9 and test it with Hadoop on jdk9 > env. I search for jiras related to JDK9. I only found SPARK-13278 > <https://issues.apache.org/jira/browse/SPARK-13278>. This means now > spark can build or run successfully on JDK9 ? > > > > > > Best Regards > > Kelly Zhang/Zhang,Liyun > > > >
