Thank you Bowen and Becket. What's the take from Flink community? Shall we wait for FLIP-27 or shall we proceed to next steps? And what the next steps are? :-)
Thanks, Sijie On Thu, Sep 5, 2019 at 2:43 PM Bowen Li <bowenl...@gmail.com> wrote: > Hi, > > I think having a Pulsar connector in Flink can be a good mutual benefit to > both communities. > > Another perspective is that Pulsar connector is the 1st streaming connector > that integrates with Flink's metadata management system and Catalog APIs. > It'll be cool to see how the integration turns out and whether we need to > improve Flink Catalog stack, which are currently in Beta, to cater to > streaming source/sink. Thus I'm in favor of merging Pulsar connector into > Flink 1.10. > > I'd suggest to submit smaller sized PRs, e.g. maybe one for basic > source/sink functionalities and another for schema and catalog integration, > just to make them easier to review. > > It doesn't seem to hurt to wait for FLIP-27. But I don't think FLIP-27 > should be a blocker in cases where it cannot make its way into 1.10 or > doesn't leave reasonable amount of time for committers to review or for > Pulsar connector to fully adapt to new interfaces. > > Bowen > > > > On Thu, Sep 5, 2019 at 3:21 AM Becket Qin <becket....@gmail.com> wrote: > > > Hi Till, > > > > You are right. It all depends on when the new source interface is going > to > > be ready. Personally I think it would be there in about a month or so. > But > > I could be too optimistic. It would also be good to hear what do Aljoscha > > and Stephan think as they are also involved in FLIP-27. > > > > In general I think we should have Pulsar connector in Flink 1.10, > > preferably with the new source interface. We can also check it in right > now > > with old source interface, but I suspect few users will use it before the > > next official release. Therefore, it seems reasonable to wait a little > bit > > to see whether we can jump to the new source interface. As long as we > make > > sure Flink 1.10 has it, waiting a little bit doesn't seem to hurt much. > > > > Thanks, > > > > Jiangjie (Becket) Qin > > > > On Thu, Sep 5, 2019 at 3:59 PM Till Rohrmann <trohrm...@apache.org> > wrote: > > > > > Hi everyone, > > > > > > I'm wondering what the problem would be if we committed the Pulsar > > > connector before the new source interface is ready. If I understood it > > > correctly, then we need to support the old source interface anyway for > > the > > > existing connectors. By checking it in early I could see the benefit > that > > > our users could start using the connector earlier. Moreover, it would > > > prevent that the Pulsar integration is being delayed in case that the > > > source interface should be delayed. The only downside I see is the > extra > > > review effort and potential fixes which might be irrelevant for the new > > > source interface implementation. I guess it mainly depends on how > certain > > > we are when the new source interface will be ready. > > > > > > Cheers, > > > Till > > > > > > On Thu, Sep 5, 2019 at 8:56 AM Becket Qin <becket....@gmail.com> > wrote: > > > > > > > Hi Sijie and Yijie, > > > > > > > > Thanks for sharing your thoughts. > > > > > > > > Just want to have some update on FLIP-27. Although the FLIP wiki and > > > > discussion thread has been quiet for some time, a few committer / > > > > contributors in Flink community were actually prototyping the entire > > > thing. > > > > We have made some good progress there but want to update the FLIP > wiki > > > > after the entire thing is verified to work in case there are some > last > > > > minute surprise in the implementation. I don't have an exact ETA yet, > > > but I > > > > guess it is going to be within a month or so. > > > > > > > > I am happy to review the current Flink Pulsar connector and see if it > > > would > > > > fit in FLIP-27. It would be good to avoid the case that we checked in > > the > > > > Pulsar connector with some review efforts and shortly after that the > > new > > > > Source interface is ready. > > > > > > > > Thanks, > > > > > > > > Jiangjie (Becket) Qin > > > > > > > > On Thu, Sep 5, 2019 at 8:39 AM Yijie Shen <henry.yijies...@gmail.com > > > > > > wrote: > > > > > > > > > Thanks for all the feedback and suggestions! > > > > > > > > > > As Sijie said, the goal of the connector has always been to provide > > > > > users with the latest features of both systems as soon as possible. > > We > > > > > propose to contribute the connector to Flink and hope to get more > > > > > suggestions and feedback from Flink experts to ensure the high > > quality > > > > > of the connector. > > > > > > > > > > For FLIP-27, we noticed its existence at the beginning of reworking > > > > > the connector implementation based on Flink 1.9; we also wanted to > > > > > build a connector that supports both batch and stream computing > based > > > > > on it. > > > > > However, it has been inactive for some time, so we decided to > provide > > > > > a connector with most of the new features, such as the new type > > system > > > > > and the new catalog API first. We will pay attention to the > progress > > > > > of FLIP-27 continually and incorporate it with the connector as > soon > > > > > as possible. > > > > > > > > > > Regarding the test status of the connector, we are following the > > other > > > > > connectors' test in Flink repository and aimed to provide > throughout > > > > > tests as we could. We are also happy to hear suggestions and > > > > > supervision from the Flink community to improve the stability and > > > > > performance of the connector continuously. > > > > > > > > > > Best, > > > > > Yijie > > > > > > > > > > On Thu, Sep 5, 2019 at 5:59 AM Sijie Guo <guosi...@gmail.com> > wrote: > > > > > > > > > > > > Thanks everyone for the comments and feedback. > > > > > > > > > > > > It seems to me that the main question here is about - "how can > the > > > > Flink > > > > > > community maintain the connector?". > > > > > > > > > > > > Here are two thoughts from myself. > > > > > > > > > > > > 1) I think how and where to host this integration is kind of less > > > > > important > > > > > > here. I believe there can be many ways to achieve it. > > > > > > As part of the contribution, what we are looking for here is how > > > these > > > > > two > > > > > > communities can build the collaboration relationship on > developing > > > > > > the integration between Pulsar and Flink. Even we can try our > best > > to > > > > > catch > > > > > > up all the updates in Flink community. We are still > > > > > > facing the fact that we have less experiences in Flink than folks > > in > > > > > Flink > > > > > > community. In order to make sure we maintain and deliver > > > > > > a high-quality pulsar-flink integration to the users who use both > > > > > > technologies, we need some help from the experts from Flink > > > community. > > > > > > > > > > > > 2) We have been following FLIP-27 for a while. Originally we were > > > > > thinking > > > > > > of contributing the connectors back after integrating with the > > > > > > new API introduced in FLIP-27. But we decided to initiate the > > > > > conversation > > > > > > as early as possible. Because we believe there are more benefits > > > doing > > > > > > it now rather than later. As part of contribution, it can help > > Flink > > > > > > community understand more about Pulsar and the potential > > integration > > > > > points. > > > > > > Also we can also help Flink community verify the new connector > API > > as > > > > > well > > > > > > as other new API (e.g. catalog API). > > > > > > > > > > > > Thanks, > > > > > > Sijie > > > > > > > > > > > > On Wed, Sep 4, 2019 at 5:24 AM Becket Qin <becket....@gmail.com> > > > > wrote: > > > > > > > > > > > > > Hi Yijie, > > > > > > > > > > > > > > Thanks for the interest in contributing the Pulsar connector. > > > > > > > > > > > > > > In general, I think having Pulsar connector with strong support > > is > > > a > > > > > > > valuable addition to Flink. So I am happy the shepherd this > > effort. > > > > > > > Meanwhile, I would also like to provide some context and recent > > > > > efforts on > > > > > > > the Flink connectors ecosystem. > > > > > > > > > > > > > > The current way Flink maintains its connector has hit the > > > scalability > > > > > bar. > > > > > > > With more and more connectors coming into Flink repo, we are > > > facing a > > > > > few > > > > > > > problems such as long build and testing time. To address this > > > > problem, > > > > > we > > > > > > > have attempted to do the following: > > > > > > > 1. Split out the connectors into a separate repository. This is > > > > > temporarily > > > > > > > on hold due to potential solution to shorten the build time. > > > > > > > 2. Encourage the connectors to stay as ecosystem project while > > > Flink > > > > > tries > > > > > > > to provide good support for functionality and compatibility > > tests. > > > > > Robert > > > > > > > has driven to create a Flink Ecosystem project website and it > is > > > > going > > > > > > > through some final approval process. > > > > > > > > > > > > > > Given the above efforts, it would be great to first see if we > can > > > > have > > > > > > > Pulsar connector as an ecosystem project with great support. It > > > would > > > > > be > > > > > > > good to hear how the Flink Pulsar connector is tested currently > > to > > > > see > > > > > if > > > > > > > we can learn something to maintain it as an ecosystem project > > with > > > > good > > > > > > > quality and test coverage. If the quality as an ecosystem > project > > > is > > > > > hard > > > > > > > to guarantee, we may as well adopt it into the main repo. > > > > > > > > > > > > > > BTW, another ongoing effort is FLIP-27 where we are making > > changes > > > to > > > > > the > > > > > > > Flink source connector architecture and interface. This change > > will > > > > > likely > > > > > > > land in 1.10. Therefore timing wise, if we are going to have > the > > > > Pulsar > > > > > > > connector in main repo, I am wondering if we should hold a > little > > > bit > > > > > and > > > > > > > let the Pulsar connector adapt to the new interface to avoid > > > shortly > > > > > > > deprecated work? > > > > > > > > > > > > > > Thanks, > > > > > > > > > > > > > > Jiangjie (Becket) Qin > > > > > > > > > > > > > > On Wed, Sep 4, 2019 at 4:32 PM Chesnay Schepler < > > > ches...@apache.org> > > > > > > > wrote: > > > > > > > > > > > > > > > I'm quite worried that we may end up repeating history. > > > > > > > > > > > > > > > > There were already 2 attempts at contributing a pulsar > > connector, > > > > > both > > > > > > > > of which failed because no committer was getting involved, > > > despite > > > > > the > > > > > > > > contributor opening a dedicated discussion thread about the > > > > > contribution > > > > > > > > beforehand and getting several +1's from committers. > > > > > > > > > > > > > > > > We should really make sure that if we welcome/approve such a > > > > > > > > contribution it will actually get the attention it deserves. > > > > > > > > > > > > > > > > As such, I'm inclined to recommend maintaining the connector > > > > outside > > > > > of > > > > > > > > Flink. We could link to it from the documentation to give it > > more > > > > > > > exposure. > > > > > > > > With the upcoming page for sharing artifacts among the > > community > > > > > (what's > > > > > > > > the state of that anyway?), this may be a better option. > > > > > > > > > > > > > > > > On 04/09/2019 10:16, Till Rohrmann wrote: > > > > > > > > > Hi everyone, > > > > > > > > > > > > > > > > > > thanks a lot for starting this discussion Yijie. I think > the > > > > Pulsar > > > > > > > > > connector would be a very valuable addition since Pulsar > > > becomes > > > > > more > > > > > > > and > > > > > > > > > more popular and it would further expand Flink's > > > > interoperability. > > > > > Also > > > > > > > > > from a project perspective it makes sense for me to place > the > > > > > connector > > > > > > > > in > > > > > > > > > the downstream project. > > > > > > > > > > > > > > > > > > My main concern/question is how can the Flink community > > > maintain > > > > > the > > > > > > > > > connector? We have seen in the past that connectors are > some > > of > > > > the > > > > > > > most > > > > > > > > > actively developed components because they need to be kept > in > > > > sync > > > > > with > > > > > > > > the > > > > > > > > > external system and with Flink. Given that the Pulsar > > community > > > > is > > > > > > > > willing > > > > > > > > > to help with maintaining, improving and evolving the > > connector, > > > > I'm > > > > > > > > > optimistic that we can achieve this. Hence, +1 for > > contributing > > > > it > > > > > back > > > > > > > > to > > > > > > > > > Flink. > > > > > > > > > > > > > > > > > > Cheers, > > > > > > > > > Till > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > On Wed, Sep 4, 2019 at 2:03 AM Sijie Guo < > guosi...@gmail.com > > > > > > > > wrote: > > > > > > > > > > > > > > > > > >> Hi Yun, > > > > > > > > >> > > > > > > > > >> Since I was the main driver behind FLINK-9641 and > > FLINK-9168, > > > > let > > > > > me > > > > > > > > try to > > > > > > > > >> add more context on this. > > > > > > > > >> > > > > > > > > >> FLINK-9641 and FLINK-9168 was created for bringing Pulsar > as > > > > > source > > > > > > > and > > > > > > > > >> sink for Flink. The integration was done with Flink 1.6.0. > > We > > > > > sent out > > > > > > > > pull > > > > > > > > >> requests about a year ago and we ended up maintaining > those > > > > > connectors > > > > > > > > in > > > > > > > > >> Pulsar for Pulsar users to use Flink to process event > > streams > > > in > > > > > > > Pulsar. > > > > > > > > >> (See > > > https://github.com/apache/pulsar/tree/master/pulsar-flink > > > > ). > > > > > The > > > > > > > > Flink > > > > > > > > >> 1.6 integration is pretty simple and there is no schema > > > > > > > considerations. > > > > > > > > >> > > > > > > > > >> In the past year, we have made a lot of changes in Pulsar > > and > > > > > brought > > > > > > > > >> Pulsar schema as the first-class citizen in Pulsar. We > also > > > > > integrated > > > > > > > > with > > > > > > > > >> other computing engines for processing Pulsar event > streams > > > with > > > > > > > Pulsar > > > > > > > > >> schema. > > > > > > > > >> > > > > > > > > >> It led us to rethink how to integrate with Flink in the > best > > > > way. > > > > > Then > > > > > > > > we > > > > > > > > >> reimplement the pulsar-flink connectors from the ground up > > > with > > > > > schema > > > > > > > > and > > > > > > > > >> bring table API and catalog API as the first-class citizen > > in > > > > the > > > > > > > > >> integration. With that being said, in the new pulsar-flink > > > > > > > > implementation, > > > > > > > > >> you can register pulsar as a flink catalog and query / > > process > > > > the > > > > > > > event > > > > > > > > >> streams using Flink SQL. > > > > > > > > >> > > > > > > > > >> This is an example about how to use Pulsar as a Flink > > catalog: > > > > > > > > >> > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > https://github.com/streamnative/pulsar-flink/blob/3eeddec5625fc7dddc3f8a3ec69f72e1614ca9c9/README.md#use-pulsar-catalog > > > > > > > > >> > > > > > > > > >> Yijie has also written a blog post explaining why we > > > > re-implement > > > > > the > > > > > > > > flink > > > > > > > > >> connector with Flink 1.9 and what are the changes we made > in > > > the > > > > > new > > > > > > > > >> connector: > > > > > > > > >> > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > https://medium.com/streamnative/use-apache-pulsar-as-streaming-table-with-8-lines-of-code-39033a93947f > > > > > > > > >> > > > > > > > > >> We believe Pulsar is not just a simple data sink or source > > for > > > > > Flink. > > > > > > > It > > > > > > > > >> actually can be a fully integrated streaming data storage > > for > > > > > Flink in > > > > > > > > many > > > > > > > > >> areas (sink, source, schema/catalog and state). The > > > combination > > > > of > > > > > > > Flink > > > > > > > > >> and Pulsar can create a great streaming warehouse > > architecture > > > > for > > > > > > > > >> streaming-first, unified data processing. Since we are > > talking > > > > to > > > > > > > > >> contribute Pulsar integration to Flink here, we are also > > > > > dedicated to > > > > > > > > >> maintain, improve and evolve the integration with Flink to > > > help > > > > > the > > > > > > > > users > > > > > > > > >> who use both Flink and Pulsar. > > > > > > > > >> > > > > > > > > >> Hope this give you a bit more background about the pulsar > > > flink > > > > > > > > >> integration. Let me know what are your thoughts. > > > > > > > > >> > > > > > > > > >> Thanks, > > > > > > > > >> Sijie > > > > > > > > >> > > > > > > > > >> > > > > > > > > >> On Tue, Sep 3, 2019 at 11:54 AM Yun Tang < > myas...@live.com> > > > > > wrote: > > > > > > > > >> > > > > > > > > >>> Hi Yijie > > > > > > > > >>> > > > > > > > > >>> I can see that Pulsar becomes more and more popular > > recently > > > > and > > > > > very > > > > > > > > >> glad > > > > > > > > >>> to see more people willing to contribute to Flink > > ecosystem. > > > > > > > > >>> > > > > > > > > >>> Before any further discussion, would you please give some > > > > > explanation > > > > > > > > of > > > > > > > > >>> the relationship between this thread to current existing > > > JIRAs > > > > of > > > > > > > > pulsar > > > > > > > > >>> source [1] and sink [2] connector? Will the contribution > > > > contains > > > > > > > part > > > > > > > > of > > > > > > > > >>> those PRs or totally different implementation? > > > > > > > > >>> > > > > > > > > >>> [1] https://issues.apache.org/jira/browse/FLINK-9641 > > > > > > > > >>> [2] https://issues.apache.org/jira/browse/FLINK-9168 > > > > > > > > >>> > > > > > > > > >>> Best > > > > > > > > >>> Yun Tang > > > > > > > > >>> ________________________________ > > > > > > > > >>> From: Yijie Shen <henry.yijies...@gmail.com> > > > > > > > > >>> Sent: Tuesday, September 3, 2019 13:57 > > > > > > > > >>> To: dev@flink.apache.org <dev@flink.apache.org> > > > > > > > > >>> Subject: [DISCUSS] Contribute Pulsar Flink connector back > > to > > > > > Flink > > > > > > > > >>> > > > > > > > > >>> Dear Flink Community! > > > > > > > > >>> > > > > > > > > >>> I would like to open the discussion of contributing > Pulsar > > > > Flink > > > > > > > > >>> connector [0] back to Flink. > > > > > > > > >>> > > > > > > > > >>> ## A brief introduction to Apache Pulsar > > > > > > > > >>> > > > > > > > > >>> Apache Pulsar[1] is a multi-tenant, high-performance > > > > distributed > > > > > > > > >>> pub-sub messaging system. Pulsar includes multiple > features > > > > such > > > > > as > > > > > > > > >>> native support for multiple clusters in a Pulsar > instance, > > > with > > > > > > > > >>> seamless geo-replication of messages across clusters, > very > > > low > > > > > > > publish > > > > > > > > >>> and end-to-end latency, seamless scalability to over a > > > million > > > > > > > topics, > > > > > > > > >>> and guaranteed message delivery with persistent message > > > storage > > > > > > > > >>> provided by Apache BookKeeper. Nowadays, Pulsar has been > > > > adopted > > > > > by > > > > > > > > >>> more and more companies[2]. > > > > > > > > >>> > > > > > > > > >>> ## The status of Pulsar Flink connector > > > > > > > > >>> > > > > > > > > >>> The Pulsar Flink connector we are planning to contribute > is > > > > built > > > > > > > upon > > > > > > > > >>> Flink 1.9.0 and Pulsar 2.4.0. The main features are: > > > > > > > > >>> - Pulsar as a streaming source with exactly-once > guarantee. > > > > > > > > >>> - Sink streaming results to Pulsar with at-least-once > > > > semantics. > > > > > (We > > > > > > > > >>> would update this to exactly-once as well when Pulsar > gets > > > all > > > > > > > > >>> transaction features ready in its 2.5.0 version) > > > > > > > > >>> - Build upon Flink new Table API Type system > (FLIP-37[3]), > > > and > > > > > can > > > > > > > > >>> automatically (de)serialize messages with the help of > > Pulsar > > > > > schema. > > > > > > > > >>> - Integrate with Flink new Catalog API (FLIP-30[4]), > which > > > > > enables > > > > > > > the > > > > > > > > >>> use of Pulsar topics as tables in Table API as well as > SQL > > > > > client. > > > > > > > > >>> > > > > > > > > >>> ## Reference > > > > > > > > >>> [0] https://github.com/streamnative/pulsar-flink > > > > > > > > >>> [1] https://pulsar.apache.org/ > > > > > > > > >>> [2] https://pulsar.apache.org/en/powered-by/ > > > > > > > > >>> [3] > > > > > > > > >>> > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > https://cwiki.apache.org/confluence/display/FLINK/FLIP-37%3A+Rework+of+the+Table+API+Type+System > > > > > > > > >>> [4] > > > > > > > > >>> > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > https://cwiki.apache.org/confluence/display/FLINK/FLIP-30%3A+Unified+Catalog+APIs > > > > > > > > >>> > > > > > > > > >>> Best, > > > > > > > > >>> Yijie Shen > > > > > > > > >>> > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >
