Re: Anyone knows how to build and spark on jdk9?

[Steve Loughran]

On 27 Oct 2017, at 19:24, Sean Owen 
> wrote:

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?


it is going to be traumatic across the stack, but it's probably best starting 
it as a background activity, just to be aware of what's going to work and where 
the trouble is(*).

But, first things first. Scala 2.12 support.

On Fri, Oct 27, 2017 at 6:02 PM Jörn Franke 
> 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.


Oracle's new retirement strategy is "odd": it'll essentially be killing java 0 
updates before java 8, and retiring java 8 as the same time as the march '18 
release. Like you say, not very motiviational for an update.

At the same time: Java 8 is going away, and at some point the move to the new 
versions will be needed, even if the new version isn't JDK9 itself. It's 
generally helpful to be a bit proactive, especially getting all the 
dependencies bumped up, sorting out build & test. The real enemy is any 
incompatible change needed in the code, or something which breaks public/stable 
APIs. That and some dependency on a library which is not compatible with java 9 
and which lacks a replacement. Either you take on the maintenance yourself 
(bad),  or you do the migration.




(*) I predict "Kerberos". it's always Kerberos. A move to a "per-app JRE will 
complicate enabling full length bit encryption", as the ASF isn't going to be 
able to ship the extended crypto JAR needed for Kerberos ad 256 bit keys.

-Steve

Re: Anyone knows how to build and spark on jdk9?

[Jean Georges Perrin]

May I ask what is the use case? Although it is a very interesting question, but 
I would be concerned about going further than a proof of concept. A lot of the 
enterprises I see and visit are barely on Java8, so starting to talk JDK 9 
might be a slight overkill but if you have a good story, I’m all for it!

jg


> On Oct 27, 2017, at 03:44, Zhang, Liyun  wrote:
> 
> Thanks your suggestion, seems that scala 2.12.4 support jdk9
>  
> Scala 2.12.4 is now available.
> 
> Our benchmarks 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] 
> Sent: Friday, October 27, 2017 10:26 AM
> To: Zhang, Liyun ; 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  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.  This means now 
> spark can build or run successfully on JDK9 ?
>  
>  
> Best Regards
> Kelly Zhang/Zhang,Liyun
>  

Re: Anyone knows how to build and spark on jdk9?

[Sean Owen]

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  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  wrote:
>
> Thanks your suggestion, seems that scala 2.12.4 support jdk9
>
>
>
> Scala 2.12.4  is now
> available.
>
> Our benchmarks
> 
>  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 ]
> *Sent:* Friday, October 27, 2017 10:26 AM
> *To:* Zhang, Liyun ; 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 
> 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
> .  This means now
> spark can build or run successfully on JDK9 ?
>
>
>
>
>
> Best Regards
>
> Kelly Zhang/Zhang,Liyun
>
>
>
>

Re: Anyone knows how to build and spark on jdk9?

[Jörn Franke]

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  wrote:
> 
> Thanks your suggestion, seems that scala 2.12.4 support jdk9
>  
> Scala 2.12.4 is now available.
> 
> Our benchmarks 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] 
> Sent: Friday, October 27, 2017 10:26 AM
> To: Zhang, Liyun ; 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  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.  This means now 
> spark can build or run successfully on JDK9 ?
>  
>  
> Best Regards
> Kelly Zhang/Zhang,Liyun
>  

RE: Anyone knows how to build and spark on jdk9?

[Zhang, Liyun]

Thanks your suggestion, seems that scala 2.12.4 support jdk9


Scala 2.12.4 is now 
available.

Our 
benchmarks
 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]
Sent: Friday, October 27, 2017 10:26 AM
To: Zhang, Liyun ; 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 
> 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.  This means now 
spark can build or run successfully on JDK9 ?


Best Regards
Kelly Zhang/Zhang,Liyun

Re: Anyone knows how to build and spark on jdk9?

[Reynold Xin]

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  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
> .  This means now
> spark can build or run successfully on JDK9 ?
>
>
>
>
>
> Best Regards
>
> Kelly Zhang/Zhang,Liyun
>
>
>