About log4j-core automatically pulling in api and spi dependencies: bear in mind that not everyone uses Gradle or Maven... I suspect many enterprise projects don't.
Does spi need to be a module? I agree on the need to have a clear Service Provider Interface which defines interfaces, abstract classes, and annotations for plugins, but does it need to live in a separate module? (Would one ever be able to use spi without core?) Overall I agree that required dependencies is good. One potential exception would be Async Loggers. I realize it would be consistent but to me it feels very core Log4j2... What do you think? On Tue, Apr 25, 2017 at 23:09 Matt Sicker <boa...@gmail.com> wrote: > I also agree that modules should really stick to required dependencies. > > As for only requiring log4j-core, the idea here is that you could still > just do: > > compile 'org.apache.logging.log4j:log4j-core:2.+' > > or whatever the equivalent is for your build system, and you'll still get > log4j-api and anything else required. You'd only need log4j-api for > logging, log4j-spi for writing custom plugins, or log4j-core to get the > standard plugins. > > On 25 April 2017 at 09:07, Mikael Ståldal <mikael.stal...@magine.com> > wrote: > > > I think we should aim for all modules having only required dependencies. > > > > We should not add any new optional dependencies, and all new modules > should > > only have required dependencies. > > > > Maybe we won't be able to get rid of all optional dependencies in > > log4j-core right away, though. Maybe we will release 2.9 with a few > > optional dependencies left. > > > > On Tue, Apr 25, 2017 at 4:03 PM, Gary Gregory <garydgreg...@gmail.com> > > wrote: > > > > > We should have consensus on the big picture here... are we all Ok with > > the > > > idea of all modules only having _required_ dependencies? > > > > > > Gary > > > > > > On Apr 25, 2017 6:57 AM, "Remko Popma" <remko.po...@gmail.com> wrote: > > > > > > > Nice analysis Mikael! > > > > > > > > I'm a bit fuzzy on log4j-spi, what was that for again? The list says > > > "core > > > > will depend on spi" but I think it's worth making an effort to > ensure > > > that > > > > basic (file) logging behavior only needs core+API... Why does spi > need > > to > > > > be separated from core? > > > > > > > > My first thought about jdbc was that since jdbc doesn't require > > external > > > > dependencies we should probably leave it in core. I guess it depends > on > > > > what we're trying to achieve with (or how far we want to take) the > > > > modularization: do we want to reduce core to its absolute minimum or > > are > > > we > > > > aiming to split off external dependencies? > > > > > > > > Looking at the list I can see how many of these make sense and at the > > > same > > > > time I'm thinking, that's a lot of modules! :-) > > > > > > > > Remko > > > > > > > > > > > > (Shameless plug) Every main() method deserves http://picocli.info > > > > > > > > > On Apr 25, 2017, at 18:51, Mikael Ståldal < > mikael.stal...@magine.com > > > > > > > wrote: > > > > > > > > > > I guess that log4-core will become: > > > > > > > > > > - log4j-core (will depend on log4j-spi) > > > > > - log4j-spi > > > > > - log4j-csv > > > > > - log4j-xml (XmlLayout) > > > > > - log4j-json (JsonLayout) > > > > > - log4j-yaml (YamlLayout) > > > > > - log4j-kafka > > > > > - log4j-smtp > > > > > - log4j-jms > > > > > - log4j-jdbc (or can this be kept in log4j-core?) > > > > > - log4j-jpa > > > > > - log4j-zeromq > > > > > - log4j-server (already done, not yet released) > > > > > - log4j-tools (command line tools) > > > > > > > > > > > > > > > Then we should also split log4j-nosql: > > > > > > > > > > - log4j-cassandra > > > > > - log4j-couchdb > > > > > - log4j-mongodb > > > > > - log4j-lucene (new, under development) > > > > > > > > > > > > > > > > > > > >> On Mon, Apr 24, 2017 at 7:43 PM, Remko Popma < > remko.po...@gmail.com > > > > > > > wrote: > > > > >> > > > > >> How many new modules are we talking about, concretely? > > > > >> > > > > >> Matt mentioned the StackOverflow questions about transitive > > > dependencies > > > > >> etc, but I imagine splitting log4j-core into 5 or more new modules > > > will > > > > >> also cause confusion... It won't be trivial for users to figure > out > > > > which > > > > >> of the many modules they do or don't need. The coarse granularity > of > > > the > > > > >> current modules is a good thing for users. > > > > >> > > > > >> What problem are we trying to solve? And how can we solve it with > > the > > > > least > > > > >> disruption to our users? > > > > >> > > > > >> Would it be an idea, for example, to provide separate jars for the > > > > separate > > > > >> modules, but in addition create a combined jar (log4j-core-all) > that > > > > >> contains all the classes in log4j-core as well as the classes in > the > > > new > > > > >> modules we split out from core? > > > > >> > > > > >> > > > > >>> On Tue, Apr 25, 2017 at 2:00 AM, Matt Sicker <boa...@gmail.com> > > > wrote: > > > > >>> > > > > >>> I agree with Ralph here. I'm sure we'll figure out rather quickly > > > which > > > > >>> modules are easy to put into rarely updated repositories. > > > > >>> > > > > >>> On 24 April 2017 at 11:39, Ralph Goers < > ralph.go...@dslextreme.com > > > > > > > >> wrote: > > > > >>> > > > > >>>> I would prefer a hybrid approach. First things should be moved > to > > > > >>>> separate modules. Then, if they don’t seem to be modified > > frequently > > > > >> they > > > > >>>> can be moved to a separate repo. For example, I think it would > be > > OK > > > > >> for > > > > >>>> the Flume Appender to be in a separate repo. It hasn’t changed > in > > > > >> quite a > > > > >>>> while and I can’t remember the last time it was modified due to > > > > changes > > > > >>> in > > > > >>>> Log4j it has and while continue to change with changes made in > > Flume > > > > >>>> releases. I imagine we have quite a few components that are > > > similar. > > > > >>>> > > > > >>>> Ralph > > > > >>>> > > > > >>>>> On Apr 24, 2017, at 8:39 AM, Gary Gregory < > > garydgreg...@gmail.com> > > > > >>>> wrote: > > > > >>>>> > > > > >>>>> On Apr 24, 2017 2:38 AM, "Mikael Ståldal" < > > > mikael.stal...@magine.com > > > > >>> > > > > >>>> wrote: > > > > >>>>> > > > > >>>>> I fully agree with Matt's both proposals. > > > > >>>>> > > > > >>>>> I'm skeptic to creating more repositories (than we already > have) > > > > >>> though. > > > > >>>> I > > > > >>>>> think that we should start by splitting out modules from > > log4j-core > > > > >> and > > > > >>>>> keep those modules in the main repository with synchronized > > > > >> versioning > > > > >>>> and > > > > >>>>> releases, at least for the 2.9 release. We can always move > those > > > > >>> modules > > > > >>>> to > > > > >>>>> other repositories later if we want to. > > > > >>>>> > > > > >>>>> > > > > >>>>> I do not like more repos either. Since we have already gone > down > > > the > > > > >>> more > > > > >>>>> modules road, I say we keep going. > > > > >>>>> > > > > >>>>> Gary > > > > >>>>> > > > > >>>>> > > > > >>>>> It is a lot of administrative work to create a new repository > (as > > > we > > > > >>> have > > > > >>>>> seen for log4j-scala), I don't want us to do all that work over > > and > > > > >>> over > > > > >>>>> again unless really necessary. > > > > >>>>> > > > > >>>>> We have a JIRA ticket for this: > > > > >>>>> https://issues.apache.org/jira/browse/LOG4J2-1650 > > > > >>>>> > > > > >>>>> I have already started by breaking out log4j-server: > > > > >>>>> https://issues.apache.org/jira/browse/LOG4J2-1851 > > > > >>>>> > > > > >>>>> I think the next step is to break out plugins (layouts and > > > appenders) > > > > >>>> with > > > > >>>>> optional 3rd party dependencies into their own modules. > > > > >>>>> > > > > >>>>> > > > > >>>>> On Sun, Apr 23, 2017 at 7:45 PM, Matt Sicker <boa...@gmail.com > > > > > > >> wrote: > > > > >>>>> > > > > >>>>>> I think I brought this topic up like 3 years ago when I was > > > working > > > > >> on > > > > >>>>>> initial OSGi support, but now that we have 3 more years worth > of > > > > >> code > > > > >>>>>> additions and optional features, I think this might be a more > > > > >>>> appropriate > > > > >>>>>> time to discuss it again in light of experience. > > > > >>>>>> > > > > >>>>>> Building log4j-core itself already takes a long time, and many > > > > >> plugins > > > > >>>>>> aren't updated very often at all. In the past, requiring users > > to > > > > >>> simply > > > > >>>>>> add log4j-core plus any transitive dependencies to use > optional > > > > >>> features > > > > >>>>>> seemed to work well enough, but I still think that's a > confusing > > > > >>>>>> distribution mechanism as demonstrated by the numerous bug > > reports > > > > >> and > > > > >>>>>> Stack Overflow posts regarding missing transitive dependencies > > for > > > > >>>> various > > > > >>>>>> features. I spent some time experimenting with Log4j Boot a > > little > > > > >>> while > > > > >>>>>> ago to help alleviate this problem, but this may be > unnecessary > > if > > > > >> we > > > > >>>> can > > > > >>>>>> agree to modularize log4j-core itself. > > > > >>>>>> > > > > >>>>>> I have two different proposals, both of which can be used at > the > > > > >> same > > > > >>>>> time. > > > > >>>>>> > > > > >>>>>> 1. Split out everything from log4j-core that requires 3rd > party > > > > >>>>>> dependencies (except for AsyncLogger, though perhaps we could > > > > >> consider > > > > >>>>>> shading and renaming those classes like some other low level > > > > >> libraries > > > > >>>> do > > > > >>>>>> with JCTools). Ideally, I'd like to see each module have > > required > > > > >>>>>> dependencies instead of optional ones, so that if, for > > instance, I > > > > >>>> include > > > > >>>>>> a "log4j-config-yaml" dependency, I know that Log4j will > support > > > > >> YAML > > > > >>>>>> configuration without having to specify the individual Jackson > > > > >>>>>> dependencies. > > > > >>>>>> > > > > >>>>>> 2. Split out from log4j-core a sort of log4j-spi module which > > > > >> defines > > > > >>>>>> interfaces, abstract classes, and annotations for plugins that > > > would > > > > >>> be > > > > >>>>>> promoted to the same level of backwards compatibility > guarantees > > > as > > > > >>>>>> log4j-api. This would aid in cementing what we really wish to > > > > >> maintain > > > > >>>>>> compatibility with in the backend while allowing other modules > > to > > > > >> have > > > > >>>>> less > > > > >>>>>> strict guarantees. > > > > >>>>>> > > > > >>>>>> With proposal #1, I'd think that we could more easily start > > moving > > > > >>>> modules > > > > >>>>>> into separate repositories and release trains. Without #2, > > though, > > > > >>> this > > > > >>>>>> makes version support more annoying to handle, but that's what > > > we'll > > > > >>>> face > > > > >>>>>> regardless as we separate more repositories. If we go this > > route, > > > > >> then > > > > >>>>>> there will be no need for a Log4j Boot subproject. > > > > >>>>>> > > > > >>>>>> What do you all think? > > > > >>>>>> > > > > >>>>>> -- > > > > >>>>>> Matt Sicker <boa...@gmail.com> > > > > >>>>>> > > > > >>>>> > > > > >>>>> > > > > >>>>> > > > > >>>>> -- > > > > >>>>> [image: MagineTV] > > > > >>>>> > > > > >>>>> *Mikael Ståldal* > > > > >>>>> Senior software developer > > > > >>>>> > > > > >>>>> *Magine TV* > > > > >>>>> mikael.stal...@magine.com > > > > >>>>> Grev Turegatan 3 | 114 46 Stockholm, Sweden | > www.magine.com > > > > >>>>> > > > > >>>>> Privileged and/or Confidential Information may be contained in > > this > > > > >>>>> message. If you are not the addressee indicated in this message > > > > >>>>> (or responsible for delivery of the message to such a person), > > you > > > > >> may > > > > >>>> not > > > > >>>>> copy or deliver this message to anyone. In such case, > > > > >>>>> you should destroy this message and kindly notify the sender by > > > reply > > > > >>>>> email. > > > > >>>> > > > > >>>> > > > > >>>> > > > > >>> > > > > >>> > > > > >>> -- > > > > >>> Matt Sicker <boa...@gmail.com> > > > > >>> > > > > >> > > > > > > > > > > > > > > > > > > > > -- > > > > > [image: MagineTV] > > > > > > > > > > *Mikael Ståldal* > > > > > Senior software developer > > > > > > > > > > *Magine TV* > > > > > mikael.stal...@magine.com > > > > > Grev Turegatan 3 | 114 46 Stockholm, Sweden | www.magine.com > > > > > > > > > > Privileged and/or Confidential Information may be contained in this > > > > > message. If you are not the addressee indicated in this message > > > > > (or responsible for delivery of the message to such a person), you > > may > > > > not > > > > > copy or deliver this message to anyone. In such case, > > > > > you should destroy this message and kindly notify the sender by > reply > > > > > email. > > > > > > > > > > > > > > > -- > > [image: MagineTV] > > > > *Mikael Ståldal* > > Senior software developer > > > > *Magine TV* > > mikael.stal...@magine.com > > Grev Turegatan 3 | 114 46 Stockholm, Sweden | www.magine.com > > > > Privileged and/or Confidential Information may be contained in this > > message. If you are not the addressee indicated in this message > > (or responsible for delivery of the message to such a person), you may > not > > copy or deliver this message to anyone. In such case, > > you should destroy this message and kindly notify the sender by reply > > email. > > > > > > -- > Matt Sicker <boa...@gmail.com> >
