Daniel, please think through these old project scenarios. Those old projects did ship their own slf4j impl + config and parsed their own logs and extracted information. They will now just fall on their knees because the logs are no longer available for them. Instead they will be somewhere in the maven logs which could be anywhere from a plugin point of view.
This is not fixed, this is broken imo. LieGrue, strub ----- Original Message ----- > From: Daniel Kulp <dk...@apache.org> > To: Maven Developers List <dev@maven.apache.org> > Cc: > Sent: Friday, December 7, 2012 1:49 PM > Subject: Re: [VOTE] Maven 3.1.0 > > >> >> Again the state of affairs of 3.1.0 today: old projects and plugins which > didnt use slf4j so far don't get any benefit from forcing slf4j on them. And > old projects and plugins which _did_ use slf4j already are now broken with > the > current trunk. I cannot see how we can seriously release this to users right > now. > > > > I don't consider them broken. I consider them fixed. Old plugins that > use SLF4J now get there information properly integrated with the rest of the > maven information. > > > Dan > > > > On Dec 7, 2012, at 7:32 AM, Mark Struberg <strub...@yahoo.de> wrote: > >>> The final proposal that I see is where we give a metadata flag >> (defaults to false) >>> which if true sets up an isolated classloader for >> the plugin allowing the plugin to use its own slf4j >> >> Stephen, this is _almost_ the same as I proposed a month ago. But I'd > do it the other way around as this would be perfectly backward compatible. >> >> I'll try to explain again what I propose: >> >> Any plugin could e.g. use a @Slf4JLogger in it's mojo. The > plugin-plugin would transfer this to a <useSlf4j>true</useSlf4j> > inside the plugin.xml. >> In this case, and _only_ in this case we would expose our internal SLF4J to > the plugin. >> >> >> Older plugins do not need it anyway as they do not use the maven-provided > slf4j yet! >> >> >> This is a win-win solution imo: >> * old integration and plugins will still work >> * new plugins can use slf4j for logging via maven >> >> >> Again the state of affairs of 3.1.0 today: old projects and plugins which > didnt use slf4j so far don't get any benefit from forcing slf4j on them. And > old projects and plugins which _did_ use slf4j already are now broken with > the > current trunk. I cannot see how we can seriously release this to users right > now. >> >> LieGrue, >> strub >> >> >>> ________________________________ >>> From: Stephen Connolly <stephen.alan.conno...@gmail.com> >>> To: Maven Developers List <dev@maven.apache.org>; Mark Struberg > <strub...@yahoo.de> >>> Sent: Friday, December 7, 2012 12:48 PM >>> Subject: Re: [VOTE] Maven 3.1.0 >>> >>> >>> But not all of those *need to*. At least until now they have needed to, > but going forward they may not need to if we are giving them an slf4j impl to > hang their hat off. >>> >>> >>> There will always be some special case plugins that have a legitimate > need to do funky logging stuff. We need a strategy for those plugins. >>> >>> >>> Jason's proposal for those cases was that they should fork a JVM. > That works if you don't need to channel objects back and forth. For some of > the plugins wanting to do 'live development' style work (I am thinking > my jszip.org experiments - I have some plans and experiments that I haven't > even pushed to there yet ;-) ) forking a JVM is a bad plan, as you then have > to > basically resort to RMI to control the forked JVM... More ports and more > sockets > and more complexity. >>> >>> >>> The next step I could see is building a fresh classloader up from > scratch within the plugin. That *should* work as long as we load a fresh set > of > slf4j-api classes (ceki?) then we are initialising slf4j a second time in the > fresh classloader and we can do as we need. Again complex though one could > argue > less complex than the RMI route. Plugin developers following this route will > have to watch out for the dreaded CCE but at least you are not having to deal > with object serialisation and RMI >>> >>> >>> The final proposal that I see is where we give a metadata flag > (defaults to false) which if true sets up an isolated classloader for the > plugin > allowing the plugin to use its own slf4j >>> >>> >>> Note that each proposal above retains the option for plugin developers > to use the previous proposal. >>> >>> >>> My vote is that we need to provide a utility library that makes the > first and second proposals facile for plugin developers and we should > probably > enable the third option also. >>> >>> >>> The correct respecting of tool chains support requires plugin > developers to follow the first route if a tool chain JVM is applied to their > plugin and to use the second when no tool chain JVM is in play... At least > for > the jetty:run and tomcat:run style plugins. >>> >>> >>> For the sonar style plugins, and my gut says the vast majority of these > use cases the most they will need is the third proposal. Without seeing a > maven-fork-utils api I cannot say that we don't need the third proposal, so > I am forced to conclude that we should support it... IOW I think we need a > metadata flag. >>> >>> >>> -Stephen >>> >>> On Friday, 7 December 2012, Mark Struberg wrote: >>> >>> basically all stuff which integrates maven does *funky logging > stuff*... >>>> >>>> >>>> >>>> >>>> ----- Original Message ----- >>>>> From: Anders Hammar <and...@hammar.net> >>>>> To: Maven Developers List <dev@maven.apache.org> >>>>> Cc: >>>>> Sent: Friday, December 7, 2012 7:25 AM >>>>> Subject: Re: [VOTE] Maven 3.1.0 >>>>> >>>>>> I'm interested to help working on adding a metadata to > enable slf4j >>>>>> visibility >>>>>> from a plugin: by default, slf4j is not visible, plugins > are expected to >>>>>> use >>>>>> plugin-api's Log. But if the plugin wants to use > core's slf4j, he >>>>> would be >>>>>> able to add an annotation in the goal requiring shared > core slf4j, then the >>>>>> plugin descriptor would enable slf4j api import from core. >>>>>> >>>>> >>>>> *If* we go this path, I think the default should be the other > way around. >>>>> I.e., the default would be to use core's slf4j and it's > impl. So the >>>>> plugin >>>>> developer needs to do an active choice to go outside > Maven's logging. Sure, >>>>> this could imply problems with existing plugins doing funky > logging stuff >>>>> (like the Sonar plugin), but I don't really see a problem > with those >>>>> plugins having to release a new version. I think it's more > important that >>>>> we get good defaults than trying to make every existing plugin > work as they >>>>> are implemented right now. >>>>> >>>>> /Anders >>>>> >>>>> >>>>>> >>>>>> Stephen: is this what you have in mind? >>>>>> >>>>>> Regards, >>>>>> >>>>>> Hervé >>>>>> >>>>>> Le vendredi 30 novembre 2012 12:20:35 Stephen Connolly a > écrit : >>>>>> > I tend to agree. There are two use-cases I see that a > plugin has for >>>>>> > bundling a logging implementation: >>>>>> > >>>>>> > 1. They are wanting to shunt the logs from the build > tool they are >>>>>> invoking >>>>>> > on to the user. Typically if they are being good > plugins they just >>>>> take >>>>>> the >>>>>> > logging output and shunt it onto > org.apache.maven.plugin.Log.info() >>>>>> > >>>>>> > 2. They are wanting to shunt the logs from the build > tool (or more >>>>> likely >>>>>> > app server) to a separate file, or tweak the level of > logs higher than >>>>>> INFO >>>>>> > for that app server/mojo execution as it will just > drown the user. >>>>>> > >>>>>> > In the first use case, Jason's point is correct. > They >>>>> shouldn't need to >>>>>> > bundle a logging implementation any more. >>>>>> > >>>>>> > The second case, Jason is arguing that they > shouldn't be using the >>>>> Maven >>>>>> > JVM for running that tool, they should be running it > in a forked JVM >>>>> and >>>>>> > then they can configure the logging in that JVM. I > disagree. Forking a >>>>>> JVM >>>>>> > for every little build tool just to control its > logging is going to >>>>> kill >>>>>> > the build time. >>>>>> > >>>>>> > My preference is for a metadata flag that says: Oy! I > know what >>>>> I'm doing >>>>>> > with logging, so don't pass logging on to me. >>>>>> > >>>>>> > While it feels like a "special case" the > truth is logging is >>>>> always, and >>>>>> > always will be, a special case! >>>>>> > >>>>>> > -Stephen >>>>>> > >>>>>> > On 30 November 2012 12:09, Benson Margulies >>>>> <bimargul...@gmail.com> >>>>>> wrote: >>>>>> > > On Thu, Nov 29, 2012 at 11:05 PM, Jason van Zyl >>>>> <ja...@tesla.io> >>>>>> wrote: >>>>>> > > > On Nov 29, 2012, at 5:56 PM, Benson > Margulies >>>>> <bimargul...@gmail.com >>>>>> > >>>>>> > > >>>>>> > > wrote: >>>>>> > > >>> Currently I'm of the mind that > if you make a >>>>> Maven plugin that uses >>>>>> > > >>>>>> > > something that employs SLF4J then the best > practice is to only >>>>> use the >>>>>> API >>>>>> > > and let the host choose the implementation, in > our case Maven. >>>>> Relying >>>>>> on >>>>>> > > SLF4J implementation specifics in a system > you're embedded in >>>>> is not >>>>>> good >>>>>> > > e.g. Logback in Sonar running in Maven using > SLF4J Simple. If y >>> >>> >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: dev-unsubscr...@maven.apache.org >> For additional commands, e-mail: dev-h...@maven.apache.org >> > > -- > Daniel Kulp > dk...@apache.org - http://dankulp.com/blog > Talend Community Coder - http://coders.talend.com > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: dev-unsubscr...@maven.apache.org > For additional commands, e-mail: dev-h...@maven.apache.org > --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@maven.apache.org For additional commands, e-mail: dev-h...@maven.apache.org
