> > David, can you elaborate why you need watermark generation in the source > for your data generators?
The training exercises should strive to provide examples of best practices. If the exercises and their solutions use env.fromSource(source, WatermarkStrategy.noWatermarks(), "name-of-source") .map(...) .assignTimestampsAndWatermarks(...) this will help establish this anti-pattern as the normal way of doing things. Most new Flink users are using a KafkaSource with a noWatermarks strategy and a SimpleStringSchema, followed by a map that does the real deserialization, followed by the real watermarking -- because they aren't seeing examples that teach how these interfaces are meant to be used. When we redo the sources used in training exercises, I want to avoid these pitfalls. David On Mon, Jun 6, 2022 at 9:12 AM Konstantin Knauf <kna...@apache.org> wrote: > Hi everyone, > > very interesting thread. The proposal for deprecation seems to have sparked > a very important discussion. Do we what users struggle with specifically? > > Speaking for myself, when I upgrade flink-faker to the new Source API an > unbounded version of the NumberSequenceSource would have been all I needed, > but that's just the data generator use case. I think, that one could be > solved quite easily. David, can you elaborate why you need watermark > generation in the source for your data generators? > > Cheers, > > Konstantin > > > > > > Am So., 5. Juni 2022 um 17:48 Uhr schrieb Piotr Nowojski < > pnowoj...@apache.org>: > > > Also +1 to what David has written. But it doesn't mean we should be > waiting > > indefinitely to deprecate SourceFunction. > > > > Best, > > Piotrek > > > > niedz., 5 cze 2022 o 16:46 Jark Wu <imj...@gmail.com> napisał(a): > > > > > +1 to David's point. > > > > > > Usually, when we deprecate some interfaces, we should point users to > use > > > the recommended alternatives. > > > However, implementing the new Source interface for some simple > scenarios > > is > > > too challenging and complex. > > > We also found it isn't easy to push the internal connector to upgrade > to > > > the new Source because > > > "FLIP-27 are hard to understand, while SourceFunction is easy". > > > > > > +1 to make implementing a simple Source easier before deprecating > > > SourceFunction. > > > > > > Best, > > > Jark > > > > > > > > > On Sun, 5 Jun 2022 at 07:29, Jingsong Lee <lzljs3620...@apache.org> > > wrote: > > > > > > > +1 to David and Ingo. > > > > > > > > Before deprecate and remove SourceFunction, we should have some > easier > > > APIs > > > > to wrap new Source, the cost to write a new Source is too high now. > > > > > > > > > > > > > > > > Ingo Bürk <airbla...@apache.org>于2022年6月5日 周日05:32写道： > > > > > > > > > I +1 everything David said. The new Source API raised the > complexity > > > > > significantly. It's great to have such a rich, powerful API that > can > > do > > > > > everything, but in the process we lost the ability to onboard > people > > to > > > > > the APIs. > > > > > > > > > > > > > > > Best > > > > > Ingo > > > > > > > > > > On 04.06.22 21:21, David Anderson wrote: > > > > > > I'm in favor of this, but I think we need to make it easier to > > > > implement > > > > > > data generators and test sources. As things stand in 1.15, unless > > you > > > > can > > > > > > be satisfied with using a NumberSequenceSource followed by a map, > > > > things > > > > > > get quite complicated. I looked into reworking the data > generators > > > used > > > > > in > > > > > > the training exercises, and got discouraged by the amount of work > > > > > involved. > > > > > > (The sources used in the training want to be unbounded, and need > > > > > > watermarking in the sources, which means that using > > > > NumberSequenceSource > > > > > > isn't an option.) > > > > > > > > > > > > I think the proposed deprecation will be better received if it > can > > be > > > > > > accompanied by something that makes implementing a simple Source > > > easier > > > > > > than it is now. People are continuing to implement new > > > SourceFunctions > > > > > > because the interfaces defined by FLIP-27 are hard to understand, > > > while > > > > > > SourceFunction is easy. Alex, I believe you were looking into > > > > > implementing > > > > > > an easier-to-use building block that could be used in situations > > like > > > > > this. > > > > > > Can we get something like that in place first? > > > > > > > > > > > > David > > > > > > > > > > > > On Fri, Jun 3, 2022 at 4:52 PM Jing Ge <j...@ververica.com> > wrote: > > > > > > > > > > > >> Hi, > > > > > >> > > > > > >> Thanks Alex for driving this! > > > > > >> > > > > > >> +1 To give the Flink developers, especially Connector developers > > the > > > > > clear > > > > > >> signal that the new Source API is recommended according to > > FLIP-27, > > > we > > > > > >> should mark them as deprecated. > > > > > >> > > > > > >> There are some open questions to discuss: > > > > > >> > > > > > >> 1. Do we need to mark all subinterfaces/subclasses as > deprecated? > > > e.g. > > > > > >> FromElementsFunction, etc. there are many. What are the > > > replacements? > > > > > >> 2. Do we need to mark all subclasses that have replacement as > > > > > deprecated? > > > > > >> e.g. ExternallyInducedSource whose replacement class, if I am > not > > > > > mistaken, > > > > > >> ExternallyInducedSourceReader is @Experimental > > > > > >> 3. Do we need to mark all related test utility classes as > > > deprecated? > > > > > >> > > > > > >> I think it might make sense to create an umbrella ticket to > cover > > > all > > > > of > > > > > >> these with the following process: > > > > > >> > > > > > >> 1. Mark SourceFunction as deprecated asap. > > > > > >> 2. Mark subinterfaces and subclasses as deprecated, if there are > > > > > graduated > > > > > >> replacements. Good example is that KafkaSource replaced > > > KafkaConsumer > > > > > which > > > > > >> has been marked as deprecated. > > > > > >> 3. Do not mark subinterfaces and subclasses as deprecated, if > > > > > replacement > > > > > >> classes are still experimental, check if it is time to graduate > > > them. > > > > > After > > > > > >> graduation, go to step 2. It might take a while for graduation. > > > > > >> 4. Do not mark subinterfaces and subclasses as deprecated, if > the > > > > > >> replacement classes are experimental and are too young to > > graduate. > > > We > > > > > have > > > > > >> to wait. But in this case we could create new tickets under the > > > > umbrella > > > > > >> ticket. > > > > > >> 5. Do not mark subinterfaces and subclasses as deprecated, if > > there > > > is > > > > > no > > > > > >> replacement at all. We have to create new tickets and wait until > > the > > > > new > > > > > >> implementation has been done and graduated. It will take a > longer > > > > time, > > > > > >> roughly 1,5 years. > > > > > >> 6. For test classes, we could follow the same rule. But I think > > for > > > > some > > > > > >> cases, we could consider doing the replacement directly without > > > going > > > > > >> through the deprecation phase. > > > > > >> > > > > > >> When we look back on all of these, we can realize it is a big > epic > > > > (even > > > > > >> bigger than an epic). It needs someone to drive it and keep > focus > > on > > > > it > > > > > >> continuously with support from the community and push the > > > development > > > > > >> towards the new Source API of FLIP-27. > > > > > >> > > > > > >> If we could have consensus for this, Alex and I could create > the > > > > > umbrella > > > > > >> ticket to kick it off. > > > > > >> > > > > > >> Best regards, > > > > > >> Jing > > > > > >> > > > > > >> > > > > > >> On Fri, Jun 3, 2022 at 3:54 PM Alexander Fedulov < > > > > > alexan...@ververica.com> > > > > > >> wrote: > > > > > >> > > > > > >>> Hi everyone, > > > > > >>> > > > > > >>> I would like to start the discussion about marking > > > > SourceFunction-based > > > > > >>> interfaces as deprecated. With the FLIP-27 APIs becoming the > new > > > > > >> standard, > > > > > >>> the old ones have to be eventually phased out. Although this > > state > > > is > > > > > >> well > > > > > >>> known within the community and no new connectors based on the > old > > > > > >>> interfaces can be accepted into the project, the footprint of > > > > > >>> SourceFunction in the user code still keeps growing (primarily > > for > > > > data > > > > > >>> generators and test utilities). I believe it is best to mark > > > > > >> SourceFunction > > > > > >>> as deprecated as soon as possible. What do you think? > > > > > >>> > > > > > >>> Best, > > > > > >>> Alexander Fedulov > > > > > >>> > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > -- > https://twitter.com/snntrable > https://github.com/knaufk >
