I have another concern which may not be closely related to this thread. Since flink doesn't include all the necessary jars, I think it is critical for flink to display meaningful error message when any class is missing. e.g. Here's the error message when I use kafka but miss including flink-json. To be honest, the kind of error message is hard to understand for new users.
Reason: No factory implements 'org.apache.flink.table.factories.DeserializationSchemaFactory'. The following properties are requested: connector.properties.bootstrap.servers=localhost:9092 connector.properties.group.id=testGroup connector.properties.zookeeper.connect=localhost:2181 connector.startup-mode=earliest-offset connector.topic=generated.events connector.type=kafka connector.version=universal format.type=json schema.0.data-type=VARCHAR(2147483647) schema.0.name=status schema.1.data-type=VARCHAR(2147483647) schema.1.name=direction schema.2.data-type=BIGINT schema.2.name=event_ts update-mode=append The following factories have been considered: org.apache.flink.table.catalog.hive.factories.HiveCatalogFactory org.apache.flink.table.module.hive.HiveModuleFactory org.apache.flink.table.module.CoreModuleFactory org.apache.flink.table.catalog.GenericInMemoryCatalogFactory org.apache.flink.table.sources.CsvBatchTableSourceFactory org.apache.flink.table.sources.CsvAppendTableSourceFactory org.apache.flink.table.sinks.CsvBatchTableSinkFactory org.apache.flink.table.sinks.CsvAppendTableSinkFactory org.apache.flink.table.planner.delegation.BlinkPlannerFactory org.apache.flink.table.planner.delegation.BlinkExecutorFactory org.apache.flink.table.planner.StreamPlannerFactory org.apache.flink.table.executor.StreamExecutorFactory org.apache.flink.streaming.connectors.kafka.KafkaTableSourceSinkFactory at org.apache.flink.table.factories.TableFactoryService.filterByFactoryClass(TableFactoryService.java:238) at org.apache.flink.table.factories.TableFactoryService.filter(TableFactoryService.java:185) at org.apache.flink.table.factories.TableFactoryService.findSingleInternal(TableFactoryService.java:143) at org.apache.flink.table.factories.TableFactoryService.find(TableFactoryService.java:113) at org.apache.flink.streaming.connectors.kafka.KafkaTableSourceSinkFactoryBase.getDeserializationSchema(KafkaTableSourceSinkFactoryBase.java:277) at org.apache.flink.streaming.connectors.kafka.KafkaTableSourceSinkFactoryBase.createStreamTableSource(KafkaTableSourceSinkFactoryBase.java:161) at org.apache.flink.table.factories.StreamTableSourceFactory.createTableSource(StreamTableSourceFactory.java:49) at org.apache.flink.table.factories.TableFactoryUtil.findAndCreateTableSource(TableFactoryUtil.java:53) ... 36 more Till Rohrmann <trohrm...@apache.org> 于2020年2月6日周四 下午11:30写道： > I would not object given that it is rather small at the moment. However, I > also think that we should have a plan how to handle the ever growing Flink > ecosystem and how to make it easily accessible to our users. E.g. one far > fetched idea could be something like a configuration script which downloads > the required components for the user. But this deserves definitely a > separate discussion and does not really belong here. > > Cheers, > Till > > On Thu, Feb 6, 2020 at 3:35 PM Hequn Cheng <he...@apache.org> wrote: > > > > > Hi everyone, > > > > Thank you all for the great inputs! > > > > I think probably what we all agree on is we should try to make a leaner > > flink-dist. However, we may also need to do some compromises considering > > the user experience that users don't need to download the dependencies > from > > different places. Otherwise, we can move all the jars in the current opt > > folder to the download page. > > > > The missing of clear rules for guiding such compromises makes things more > > complicated now. I would agree that the decisive factor for what goes > into > > Flink's binary distribution should be how core it is to Flink. Meanwhile, > > it's better to treat Flink API as a (core) core to Flink. Not only it is > a > > very clear rule that easy to be followed but also in most cases, API is > > very significant and deserved to be included in the dist. > > > > Given this, it might make sense to put flink-ml-api and flink-ml-lib into > > the opt. > > What do you think? > > > > Best, > > Hequn > > > > On Wed, Feb 5, 2020 at 12:39 AM Chesnay Schepler <ches...@apache.org> > > wrote: > > > >> Around a year ago I started a discussion > >> < > http://apache-flink-user-mailing-list-archive.2336050.n4.nabble.com/DISCUSS-Towards-a-leaner-flink-dist-tp25615.html > > > >> on reducing the amount of jars we ship with the distribution. > >> > >> While there was no definitive conclusion there was a shared sentiment > >> that APIs should be shipped with the distribution. > >> > >> On 04/02/2020 17:25, Till Rohrmann wrote: > >> > >> I think there is no such rule that APIs go automatically into opt/ and > >> "libraries" not. The contents of opt/ have mainly grown over time w/o > >> following a strict rule. > >> > >> I think the decisive factor for what goes into Flink's binary > distribution > >> should be how core it is to Flink. Of course another important > >> consideration is which use cases Flink should promote "out of the box" > (not > >> sure whether this is actual true for content shipped in opt/ because you > >> also have to move it to lib). > >> > >> For example, Gelly would be an example which I would rather see as an > >> optional component than shipping it with every Flink binary > distribution. > >> > >> Cheers, > >> Till > >> > >> On Tue, Feb 4, 2020 at 11:24 AM Becket Qin <becket....@gmail.com> < > becket....@gmail.com> wrote: > >> > >> > >> Thanks for the suggestion, Till. > >> > >> I am curious about how do we usually decide when to put the jars into > the > >> opt folder? > >> > >> Technically speaking, it seems that `flink-ml-api` should be put into > the > >> opt directory because they are actually API instead of libraries, just > like > >> CEP and Table. > >> > >> `flink-ml-lib` seems to be on the border. On one hand, it is a library. > On > >> the other hand, unlike SQL formats and Hadoop whose major code are > outside > >> of Flink, the algorithm codes are in Flink. So `flink-ml-lib` is more > like > >> those of built-in SQL UDFs. So it seems fine to either put it in the opt > >> folder or in the downloads page. > >> > >> From the user experience perspective, it might be better to have both > >> `flink-ml-lib` and `flink-ml-api` in opt folder so users needn't go to > two > >> places for the required dependencies. > >> > >> Thanks, > >> > >> Jiangjie (Becket) Qin > >> > >> On Tue, Feb 4, 2020 at 2:32 PM Hequn Cheng <he...@apache.org> < > he...@apache.org> wrote: > >> > >> > >> Hi Till, > >> > >> Thanks a lot for your suggestion. It's a good idea to offer the flink-ml > >> libraries as optional dependencies on the download page which can make > >> > >> the > >> > >> dist smaller. > >> > >> But I also have some concerns for it, e.g., the download page now only > >> includes the latest 3 releases. We may need to find ways to support more > >> versions. > >> On the other hand, the size of the flink-ml libraries now is very > >> small(about 246K), so it would not bring much impact on the size of > dist. > >> > >> What do you think? > >> > >> Best, > >> Hequn > >> > >> On Mon, Feb 3, 2020 at 6:24 PM Till Rohrmann <trohrm...@apache.org> < > trohrm...@apache.org> > >> > >> wrote: > >> > >> An alternative solution would be to offer the flink-ml libraries as > >> optional dependencies on the download page. Similar to how we offer the > >> different SQL formats and Hadoop releases [1]. > >> > >> [1] https://flink.apache.org/downloads.html > >> > >> Cheers, > >> Till > >> > >> On Mon, Feb 3, 2020 at 10:19 AM Hequn Cheng <he...@apache.org> < > he...@apache.org> wrote: > >> > >> > >> Thank you all for your feedback and suggestions! > >> > >> Best, Hequn > >> > >> On Mon, Feb 3, 2020 at 5:07 PM Becket Qin <becket....@gmail.com> < > becket....@gmail.com> > >> > >> wrote: > >> > >> Thanks for bringing up the discussion, Hequn. > >> > >> +1 on adding `flink-ml-api` and `flink-ml-lib` into opt. This would > >> > >> make > >> > >> it much easier for the users to try out some simple ml tasks. > >> > >> Thanks, > >> > >> Jiangjie (Becket) Qin > >> > >> On Mon, Feb 3, 2020 at 4:34 PM jincheng sun < > >> > >> sunjincheng...@gmail.com > >> > >> wrote: > >> > >> > >> Thank you for pushing forward @Hequn Cheng <he...@apache.org> < > he...@apache.org> ! > >> > >> Hi @Becket Qin <becket....@gmail.com> <becket....@gmail.com> , Do you > have any concerns > >> > >> on > >> > >> this ? > >> > >> Best, > >> Jincheng > >> > >> Hequn Cheng <he...@apache.org> <he...@apache.org> 于2020年2月3日周一 > 下午2:09写道： > >> > >> > >> Hi everyone, > >> > >> Thanks for the feedback. As there are no objections, I've opened a > >> > >> JIRA > >> > >> issue(FLINK-15847[1]) to address this issue. > >> The implementation details can be discussed in the issue or in the > >> following PR. > >> > >> Best, > >> Hequn > >> > >> [1] https://issues.apache.org/jira/browse/FLINK-15847 > >> > >> On Wed, Jan 8, 2020 at 9:15 PM Hequn Cheng <chenghe...@gmail.com> < > chenghe...@gmail.com> > >> > >> wrote: > >> > >> Hi Jincheng, > >> > >> Thanks a lot for your feedback! > >> Yes, I agree with you. There are cases that multi jars need to > >> > >> be > >> > >> uploaded. I will prepare another discussion later. Maybe with a > >> > >> simple > >> > >> design doc. > >> > >> Best, Hequn > >> > >> On Wed, Jan 8, 2020 at 3:06 PM jincheng sun < > >> > >> sunjincheng...@gmail.com> > >> > >> wrote: > >> > >> > >> Thanks for bring up this discussion Hequn! > >> > >> +1 for include `flink-ml-api` and `flink-ml-lib` in opt. > >> > >> BTW: I think would be great if bring up a discussion for upload > >> > >> multiple > >> > >> Jars at the same time. as PyFlink JOB also can have the benefit > >> > >> if > >> > >> we > >> > >> do > >> > >> that improvement. > >> > >> Best, > >> Jincheng > >> > >> > >> Hequn Cheng <chenghe...@gmail.com> <chenghe...@gmail.com> 于2020年1月8日周三 > 上午11:50写道： > >> > >> > >> Hi everyone, > >> > >> FLIP-39[1] rebuilds Flink ML pipeline on top of TableAPI > >> > >> which > >> > >> moves > >> > >> Flink > >> > >> ML a step further. Base on it, users can develop their ML > >> > >> jobs > >> > >> and > >> > >> more > >> > >> and > >> > >> more machine learning platforms are providing ML services. > >> > >> However, the problem now is the jars of flink-ml-api and > >> > >> flink-ml-lib > >> > >> are > >> > >> only exist on maven repo. Whenever users want to submit ML > >> > >> jobs, > >> > >> they > >> > >> can > >> > >> only depend on the ml modules and package a fat jar. This > >> > >> would be > >> > >> inconvenient especially for the machine learning platforms on > >> > >> which > >> > >> nearly > >> > >> all jobs depend on Flink ML modules and have to package a fat > >> > >> jar. > >> > >> Given this, it would be better to include jars of > >> > >> flink-ml-api > >> > >> and > >> > >> flink-ml-lib in the `opt` folder, so that users can directly > >> > >> use > >> > >> the > >> > >> jars > >> > >> with the binary release. For example, users can move the jars > >> > >> into > >> > >> the > >> > >> `lib` folder or use -j to upload the jars. (Currently, -j > >> > >> only > >> > >> support > >> > >> upload one jar. Supporting multi jars for -j can be discussed > >> > >> in > >> > >> another > >> > >> discussion.) > >> > >> Putting the jars in the `opt` folder instead of the `lib` > >> > >> folder > >> > >> is > >> > >> because > >> > >> currently, the ml jars are still optional for the Flink > >> > >> project by > >> > >> default. > >> > >> What do you think? Welcome any feedback! > >> > >> Best, > >> > >> Hequn > >> > >> [1] > >> > >> > >> > >> > https://cwiki.apache.org/confluence/display/FLINK/FLIP-39+Flink+ML+pipeline+and+ML+libs > >> > >> > >> > -- Best Regards Jeff Zhang
