Never thought about "Experimental" meaning unstable but I agree it sounds better to use the term "Evolving".
On Sun, Feb 7, 2016 at 12:45 AM, Fabian Hueske <fhue...@gmail.com> wrote: > I agree, Experimental rather suggests unstable behavior than potentially > changing interfaces. > +1 for renaming to @PublicEvolving. > > Other opinions on strictly annotating all public interfaces with @Public / > @PublicEvolving and > defaulting to @Internal for all remaining interfaces? > > 2016-02-06 15:27 GMT+01:00 Stephan Ewen <se...@apache.org>: > >> What "Experimental" is really saying is "Public, but not API stable". In >> that sense, "Internal" is not suitable, as it suggests that a method will >> never be public. >> >> What would you think of renaming "Experimental" to "PublicEvolving" ? >> >> That would carry pretty much explicitly the meaning that it is intended for >> public use, the basic concept will stay, but it may change a bit (code >> using that may be adjusted a bit in the future). In contrast "Experimental" >> sounds to me like "no idea if that class/feature is going to be there in >> the future". >> >> What do you think? >> >> Stephan >> >> >> On Sat, Feb 6, 2016 at 3:17 PM, Stephan Ewen <se...@apache.org> wrote: >> >> > Hi! >> > >> > These suggestions sound good in general. >> > >> > I am wondering if "Experimental" is not the wrong word here, because most >> > of the things are not experimental, but just possibly subject to slight >> > changes (though API breaking). >> > >> > Experimental has the connotation that something is unstable (execution >> > wise) and should best be avoided altogether. >> > If half of the Flink code base is marked "Experimental", it seems to >> > contradict that this is actually in 1.0 shape. >> > >> > I actually like the term "Internal" that was also suggested. It pretty >> > much says what we actually want to say: A certain method or class is not >> > declared part of the public API, but as of now only internal API. >> > >> > Greetings, >> > Stephan >> > >> > >> > >> > On Fri, Feb 5, 2016 at 8:38 PM, Fabian Hueske <fhue...@gmail.com> wrote: >> > >> >> Hi, >> >> >> >> @Experimental and @Internal have the class scope, because we need to be >> >> able to mark internal classes of @Public classes as experimental or >> >> internal. >> >> >> >> In some cases we annotated classes as @Public and all (or most) methods >> as >> >> @Experimental, to indicate that a class can be used, but its internals >> >> might change. >> >> For example TypeInformation is a public class (and many classes that >> >> extend >> >> this class) but most methods are @Experimental to allow users to used a >> >> TypeInformation as is, but keep the freedom to change the internals. If >> >> you >> >> find something that does not look correct, please start a discussion >> >> about. >> >> The annotations can still be changed before the 1.0 release. >> >> >> >> I agree with Max that annotating more classes with @Experimental (not >> only >> >> inner classes) would be a good idea. >> >> IMO, we should annotate all classes that belong to the user-facing API >> >> with >> >> either @Public or @Experimental. This would mean that all non-annotated >> >> classes are not part of the API and must be considered as internal. I >> >> believe this would avoid a lot of uncertainty and also easy the >> annotation >> >> management as a whole. For instance, we can more easily check how the >> API >> >> (stable and experimental) changed between releases. >> >> >> >> Cheers, Fabian >> >> >> >> 2016-02-05 17:24 GMT+01:00 Maximilian Michels <m...@apache.org>: >> >> >> >> > Hi Robert, >> >> > >> >> > Thanks a lot for all the work of going through the classes. At first >> >> > sight, the classes look quite well chosen. >> >> > >> >> > One question concerning the @Public, @Experimental, and @Internal >> >> > annotations: >> >> > >> >> > @Public may only be used for classes or interfaces. @Experimental or >> >> > @Internal are used for marking methods in @Public classes only? If >> >> > that is the case, we should restrict the annotations to this scope via >> >> > @Target. The current master also permits to tag classes with >> >> > @Experimental or @Internal. >> >> > >> >> > Marking classes with @Experimental might actually make sense. What was >> >> > the rational behind always declaring a class public first to restrict >> >> > its methods to internal or experimental? >> >> > >> >> > Cheers, >> >> > Max >> >> > >> >> > On Fri, Feb 5, 2016 at 3:07 PM, Robert Metzger <rmetz...@apache.org> >> >> > wrote: >> >> > > Hi, >> >> > > >> >> > > tl;dr: we now have @Public, @Internal, @Experimental annotations. >> >> Check >> >> > > your stuff before the release! >> >> > > >> >> > > Fabian and I spend some time the last weeks to annotate all classes >> we >> >> > > consider to be userfacing and stable with the "*@Public*" >> annotation. >> >> I >> >> > > just pushed those changes to master. >> >> > > >> >> > > There is also an annotation "*@Internal*" for marking interfaces >> users >> >> > > should not use because they are internal to the system (for example >> >> > > "DataStream.getId()"). >> >> > > >> >> > > The annotation "*@Experimental*" marks unstable methods within >> stable >> >> > > classes (for example SingleOutputStreamOperator.uid()). >> >> > > Also note that we should also annotate @Deprecated methods with >> >> > > @Experimental so that they are not part of the stable interface >> (this >> >> > works >> >> > > only before the 1.0 release). I checked that all current @Deprecated >> >> > > annotations are excluded. >> >> > > >> >> > > >> >> > > *I would like to ask everyone to spend some time before the 1.0 >> >> release >> >> > to >> >> > > go through some core classes and see if there is anything we >> forgot.* >> >> > > *We will not be able to touch methods and classes which are public >> >> after >> >> > > the 1.0 release.* >> >> > > >> >> > > Some areas where I feel we should check closely are the following: >> >> > > - InputFormats >> >> > > - State-related classes >> >> > > - Windowing related classes >> >> > > - DataStream API (global() / forward(); output to files; ... ). >> >> > > >> >> > > Fabian and I also realized that there are some downsides to this >> >> > annotation >> >> > > approach. >> >> > > a) By not annotating all classes, its easy to forget some classes. >> And >> >> > its >> >> > > not obvious to users that "no annotation" means "not public". >> >> > > >> >> > > b) For example the "SourceFunction.SourceContext" interface is >> @Public >> >> > > because users use the methods of the interface. >> >> > > However, the underlying implementations are internal to Flink (users >> >> will >> >> > > most likely not implement their own SourceContexts). Adding a new >> >> method >> >> > to >> >> > > the SourceContext interface will break its compatibilty (because >> users >> >> > > would need to implement the new method), however, for API users it >> >> does >> >> > not >> >> > > matter when we are adding new methods. >> >> > > We decided to make the interface @Public, but we added a comment >> >> > explaining >> >> > > the issue. >> >> > > If we want to add a method after the 1.0 release, we can define an >> >> > exclude >> >> > > in the maven plugin which enforces the interface stability. >> >> > > >> >> > > >> >> > > For making the whole annotation analysis business a bit easier, I'm >> >> > > currently working on a little tool to output a list of public >> classes >> >> and >> >> > > methods. I'll post that on the mailing list at a later point. >> >> > > >> >> > > Regards, >> >> > > Robert >> >> > >> >> >> > >> > >>
