[wildfly-dev] Multi-release module JARs

[Tristan Tarrant]

I commented on GitHub, but probably this is more appropriate:

I really so no point in building releases with JDK 8 any more:

* Using the -release 8 compiler argument produces the correct bytecode 
and verifies JDK method signature compatibility similar to what animal 
sniffer did
* It acts as an obstacle to the usage of JDK-specific improvements
* Raises awareness about incompatibilities that might happen with newer 
JDKs.

I would even go as far as saying that you should build upstream 
nightlies with the latest stable JDK (14) even if it isn't an LTS just 
to validate that last statement.


Tristan



On 10/06/2020 23:39, Brian Stansberry wrote:
> Thanks for this thread, Paul.
> 
> On Wed, Jun 10, 2020 at 3:31 PM Paul Ferraro <paul.ferraro at redhat.com 
> <mailto:paul.ferraro at redhat.com>> wrote:
> 
>     In version 30 of jboss-parent-pom, David Lloyd added the ability to
>     easily produce multi-release jars [1].  While several components
>     consumed by WildFly currently produce multi-release jars (e.g.
>     wildfly-common, Undertow, Infinispan, etc.), as far as I am aware,
>     none of the modules in WildFly (or wf-core) do this.
> 
>     I recently created a pull request to WildFly [2] that ports a
>     collection class from Undertow [3], which, when built using Java 9+,
>     results in faster expiration scheduling for persistent HttpSessions
>     and local @Stateful EJBs.  While the changes introduced in this PR are
>     still compatible with JDK 8 [4], this optimization will not be
>     available to users unless they build wildfly using JDK 9+ in order to
>     produce the requisite multi-release jar for the
>     wildfly-clustering-ee-cache module.
> 
>     What do people think about this?
> 
>     Is there any reason why we should *not* compile using JDK 11 when
>     building releases (while still maintaining Java 8 source
>     compatibility, of course)?
> 
> 
> One issue I can think of is CI. We'd probably need to alter jobs to 
> build with JDK 11 and then test with JDK 8. I think our integration 
> testsuite runs for JDK 8 should be running a server built the way a 
> released server is built.
> 
> The tests in the subsystems wouldn't run with JDK 8 unless we had 
> separate jobs just for that purpose (which is no big deal.)
> 
> To be fair, our JDK 11 CI jobs are building with JDK 11 and then testing 
> that, and our releases are built with JDK 8. So the existence of a 
> mismatch is not new. My impression though is JDK 8 remains dominant, so 
> shifting the mismatch to the JDK 8 side is a concern.
> 
> This isn't a showstopper kind of thing for me, it's just something to 
> think about and make a conscious plan.
> 
> 
>     Even if we continue to create releases using JDK 8 builds, does anyone
>     object to giving users the  option to build WildFly with multi-release
>     module jars when compiling with a more recent JDK version?
> 
> 
> I don't.
> 
> 
>     [1] https://issues.redhat.com/browse/WFLY-10178
>     [2] https://github.com/wildfly/wildfly/pull/13334
>     [3]
>     https://github.com/undertow-io/undertow/blob/master/core/src/main/java9/io/undertow/util/FastConcurrentDirectDeque.java
>     [4] https://ci.wildfly.org/buildConfiguration/WFPR/207451
> 
>     _______________________________________________
>     wildfly-dev mailing list
>     wildfly-dev at lists.jboss.org <mailto:wildfly-dev at lists.jboss.org>
>     https://lists.jboss.org/mailman/listinfo/wildfly-dev
> 
> 
> 
> -- 
> Brian Stansberry
> Manager, Senior Principal Software Engineer
> Red Hat
> 
> _______________________________________________
> wildfly-dev mailing list
> wildfly-dev at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/wildfly-dev
>