[infinispan-dev] Why JCache embedded has core as provided dependency

[Sebastian Laskawiec]

Hey,

The change was introduced by this commit [1] and relates to this JIRAs
[2][3]. The root cause is in [3].

Imagine a scenario where you add JCache module to your together
infinispan-embedded. If your classpath was constructed in such a way that
infinispan-embedded was before infinispan-core (classpath is scanned from
left to right in standalone apps), we could get a relocated (uber jars move
some classes into other packages) logger. That caused class mismatch
errors. It is worth to mention that it will happen to all relocated
classes, logger was just an example. And we need to relocate them, since a
user might want to use his own, newer version of DMR or any other library.
So there's no perfect solution here.

Now a lot of time passed since then and we changed quite a few things. So
this topic probably needs to be revisited.

So the first question that we should ask, shall we allow putting jcache and
infinispan-embedded together on the classpath. If the answer is yes, I
believe it should stay as it is (since the user always have a choice
whether he wants to use jcache with or without uber jar). The same question
needs to be asked for Spring modules as well as all cache stores. The
behavior needs to be consistent across all those modules.

If the answer is no (which is also valid because jcache is already present
in embedded uber jar), we should migrate all JBoss Logging references to
Infinispan Common Logging (as Tristan did here [4]) and we can make
infinispan-core as a compile time dependency to jcache. Even though
migrating to Infinispan logger is not necessary, this way we won't break
users app which used infinispan-embedded + jcache approach. Of course the
same applies to Spring and Cache stores modules.

I think the latter approach deserves some exploration. I would vote for
moving that way.

Thanks,
Sebastian

[1]
https://github.com/infinispan/infinispan/commit/720f158cce38d86b292e1ce77b75509342007739
[2] https://issues.jboss.org/browse/ISPN-6295
[3] https://issues.jboss.org/browse/ISPN-6132
[4] https://github.com/infinispan/infinispan/pull/4140/files


On Wed, Jun 7, 2017 at 11:19 AM Galder Zamarreño <galder at redhat.com> wrote:

> Hi all,
>
> Re:
> https://github.com/spring-projects/spring-boot/pull/9417#discussion_r120375579
>
> Stéphane makes a good point there, why did we make core provided
> dependency? It does feel a bit of a pain that anyone that depends on jcache
> embedded also needs to depend on core.
>
> Any more details behind this decision?
>
> Cheers,
> --
> Galder Zamarreño
> Infinispan, Red Hat
>
> --

SEBASTIAN ŁASKAWIEC

INFINISPAN DEVELOPER

Red Hat EMEA <https://www.redhat.com/>
<https://red.ht/sig>
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