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From Dawid Wysakowicz <wysakowicz.da...@gmail.com>
Subject Re: [DISCUSS]: Integrating Flink Table API & SQL with CEP
Date Tue, 13 Jun 2017 06:35:02 GMT
Hi all,

Integrating SQL with CEP seems like a really nice idea. Unfortunately I had
time just for a brief look at the design doc, but it looks really cool and
thorough. Also will have a second run tomorrow and will try to provide more
comments. Anyway will be glad to help pushing the initiative forward.

Z pozdrowieniami! / Cheers!

Dawid Wysakowicz

*Data/Software Engineer*

Skype: dawid_wys | Twitter: @OneMoreCoder

<http://getindata.com/>

2017-06-13 8:19 GMT+02:00 yueting chen <yestinmail@gmail.com>:

> Hi Dian & Jark,
>
> I checked out your prototype code, but it didn't pass the CEPITCase test in
> the flink-table component.
> It turns out that in the `MatchCodeGenerator.scala` file, line 74 should
> use `${classOf[IterativeCondition.Context[_]].getCanonicalName}` instead
> of
> `${classOf[IterativeCondition.Context[_]]}`.
>
> I've also read your desgin document and it looks fine to me. Actually, I am
> working on the same thing recently, I think maybe we can work together to
> push this forward.
>
> Thanks,
> Yueting Chen
>
> On Tue, Jun 13, 2017 at 10:44 AM, Dian Fu <dianfu@apache.org> wrote:
>
> > Hi Fabian,
> >
> > We have evaluated the missing features of Flink CEP roughly, it should
> not
> > be quite difficult to support them. Kostas, Dawid, what's your thought?
> >
> > For supporting MATCH_RECOGNIZE, do you think we could create the JIRAs
> and
> > start to work right now or we should wait until the release of calcite
> > 1.13?
> >
> > Btw, could you help to add me(dian.fu) to the contributor list, then I
> can
> > assign the JIRAs to myself? Thanks a lot.
> >
> > Best regards,
> > Dian
> >
> > On Tue, Jun 13, 2017 at 3:59 AM, Fabian Hueske <fhueske@gmail.com>
> wrote:
> >
> > > Hi Jark,
> > >
> > > Thanks for updating the design doc and sharing your prototype!
> > > I didn't look at the code in detail, but the fact that it is less than
> 1k
> > > LOC is very promising. It seems that most of the complex CEP logic can
> be
> > > reused :-)
> > > Adding a dependency on flink-cep should be fine, IMO. It is a very slim
> > > library with almost none external dependencies.
> > >
> > > Regarding the missing features of Flink CEP that you listed in the
> design
> > > doc, it would be good to get some in put from Kostas and Dawid which
> are
> > > the main contributors to CEP.
> > > Do you have already plans regarding some of the missing features or can
> > you
> > > assess how hard it would be to integrate them?
> > >
> > > Cheers, Fabian
> > >
> > > Btw. The Calcite community started a discussion about releasing Calcite
> > > 1.13. So, the missing features might soon be available.
> > >
> > > 2017-06-12 14:25 GMT+02:00 Jark Wu <jark@apache.org>:
> > >
> > > > Hi guys,
> > > >
> > > > Good news! We have made a prototype for integrating CEP and SQL. See
> > this
> > > > link
> > > > https://github.com/apache/flink/compare/master...
> > > > wuchong:cep-on-sql?expand=1
> > > >
> > > >
> > > > You can check CepITCase to try the simple CQL example.
> > > >
> > > > Meanwhile, we updated our design doc with additional implementation
> > > detail,
> > > > including how
> > > > to translate MATCH_RECOGNIZE into CEP API, and the features needed to
> > add
> > > > to Flink CEP,
> > > > and the implementation plan. See the document
> > > > https://docs.google.com/document/d/1HaaO5eYI1VZjyhtVPZOi3jVzikU7i
> > > > K15H0YbniTnN30/edit#heading=h.4oas4koy8qu3
> > > >
> > > > In the prototype, we make flink-table dependency on flink-cep. Do you
> > > think
> > > > that is fine?
> > > >
> > > > What do you think about the prototype and the design doc ?
> > > >
> > > > Any feedbacks are welcome!
> > > >
> > > > Cheers,
> > > > Jark Wu
> > > >
> > > >
> > > > 2017-06-08 17:54 GMT+08:00 Till Rohrmann <trohrmann@apache.org>:
> > > >
> > > > > Thanks for sharing your ideas with the community. I really like the
> > > > design
> > > > > document and think that it's a good approach to follow Oracle's SQL
> > > > > extension for pattern matching. Looking forward to having support
> for
> > > SQL
> > > > > with CEP capabilities :-)
> > > > >
> > > > > Cheers,
> > > > > Till
> > > > >
> > > > > On Thu, Jun 8, 2017 at 8:57 AM, Jark Wu <jark@apache.org> wrote:
> > > > >
> > > > > > Hi  @Kostas, @Fabian, thank you for your support.
> > > > > >
> > > > > > @Fabian, I totally agree with you that we should focus on SQL
> > first.
> > > > > Let's
> > > > > > keep Table API in mind and discuss that later.
> > > > > >
> > > > > > Regarding to the orderBy() clause, I'm not sure about that.
I
> think
> > > it
> > > > > > makes sense to make it required in streaming mode(either order
by
> > > > rowtime
> > > > > > or order by proctime). But CEP also works in batch mode, and
not
> > > > > necessary
> > > > > > to order by some column. Nevertheless, we can support CEP on
> batch
> > > SQL
> > > > > > later.
> > > > > >
> > > > > > We are estimating how to implement MATCH_RECOGNIZE with CEP
> library
> > > > (with
> > > > > > NFA, CEP operator). And we will output a detailed doc and a
> > prototype
> > > > in
> > > > > > the next days.
> > > > > >
> > > > > > Regards,
> > > > > > Jark Wu
> > > > > >
> > > > > >
> > > > > > 2017-06-07 21:40 GMT+08:00 Fabian Hueske <fhueske@gmail.com>:
> > > > > >
> > > > > >> Thanks Dian and Jark for this proposal!
> > > > > >>
> > > > > >> As you wrote, Till and I (and Kostas) have been thinking
about
> > this
> > > > for
> > > > > >> some time but haven't had time to work on this feature.
> > > > > >> I think it would be a great addition and value add for Flink's
> SQL
> > > > > >> support and Table API.
> > > > > >>
> > > > > >> I read the proposal and think it is very good. We might
need to
> > add
> > > a
> > > > > bit
> > > > > >> more details, esp. when planning the concrete steps of the
> > > > > implementation.
> > > > > >>
> > > > > >> A few comments to the proposal:
> > > > > >> - IMO, the development should start focusing on SQL and
its
> > > semantics.
> > > > > >> Pattern support for the Table API should be added later.
We
> > followed
> > > > > that
> > > > > >> approach for the OVER windows and I think it worked quiet
well.
> > > > > >> - We probably want to reuse as much as possible from the
CEP
> > > library.
> > > > > >> That means we need to check if the semantics of the CEP
library
> > and
> > > > > >> Oracle's PATTERN syntax are aligned (or how we can express
the
> > > PATTERN
> > > > > >> semantics with the CEP library). This should be one of the
first
> > > > steps,
> > > > > IMO.
> > > > > >> - I would make the orderBy() clause required. In regular
SQL
> rows
> > > have
> > > > > no
> > > > > >> order, so we need to make that explicit (this would also
be
> > > consistent
> > > > > with
> > > > > >> the OVER windows).
> > > > > >>
> > > > > >> Let me know what you think.
> > > > > >>
> > > > > >> Best, Fabian
> > > > > >>
> > > > > >> 2017-06-07 11:41 GMT+02:00 Kostas Kloudas <
> > > > k.kloudas@data-artisans.com
> > > > > >:
> > > > > >>
> > > > > >>> Thanks a lot for opening the discussion!
> > > > > >>>
> > > > > >>> This is a really interesting idea that has been in our
heads
> > > > > >>> since the first implementation of the CEP library.
> > > > > >>>
> > > > > >>> A big +1 for moving forward with this.
> > > > > >>>
> > > > > >>> And as for the design document, I will definitely have
a look
> > > > > >>> and comment there.
> > > > > >>>
> > > > > >>> Kostas
> > > > > >>>
> > > > > >>> On Jun 7, 2017, at 10:05 AM, Jark Wu <jark@apache.org>
wrote:
> > > > > >>>
> > > > > >>> Sorry, I forgot to cc you guys @Fabian, @Timo, @Till,
@Kostas
> > > > > >>>
> > > > > >>> 2017-06-07 15:42 GMT+08:00 Jark Wu <jark@apache.org>:
> > > > > >>>
> > > > > >>>> Hi devs,
> > > > > >>>>
> > > > > >>>> Dian and me and our teammates have investigated
this for a
> long
> > > > time.
> > > > > >>>> We think consolidating Flink SQL and CEP is an exciting
thing
> > for
> > > > > Flink.
> > > > > >>>> It'll make SQL more powerful and give users the
ability to
> > easily
> > > > and
> > > > > >>>> quickly build CEP applications.  And I find Flink
community
> has
> > > also
> > > > > talked
> > > > > >>>> about this idea before, such as the mailing list
[1] and [2]
> and
> > > > > Fabian &
> > > > > >>>> Till's talk in Flink Forward 2016 [3].
> > > > > >>>>
> > > > > >>>> I think THIS IS THE POINT to bring up this topic
again.
> Because
> > we
> > > > > >>>> already have pattern matching foundation in Flink
CEP library,
> > and
> > > > > Stream
> > > > > >>>> SQL is ready now and Calcite has partially supported
pattern
> > > > matching
> > > > > >>>> syntax!  We also drafted a design doc about how
to integrate
> SQL
> > > and
> > > > > CEP,
> > > > > >>>> and how to support CEP on Table API.
> > > https://docs.google.com/docume
> > > > > >>>> nt/d/1HaaO5eYI1VZjyhtVPZOi3jVzikU7iK15H0YbniTnN30/edit?usp=
> > > sharing
> > > > > >>>>
> > > > > >>>>
> > > > > >>>> @Fabian, @Timo, @Till, @Kostas I include you into
this
> > discussion,
> > > > it
> > > > > >>>> would be great to hear your response.
> > > > > >>>>
> > > > > >>>>
> > > > > >>>> What do others think?
> > > > > >>>>
> > > > > >>>>
> > > > > >>>> [1] http://apache-flink-mailing-list-archive.1008284.n3.
> > nabble.c
> > > > > >>>> om/Add-CEP-library-to-Flink-td9743.html#a9787
> > > > > >>>>
> > > > > >>>> [2] http://apache-flink-mailing-list-archive.1008284.n3.
> > nabble.c
> > > > > >>>> om/Effort-to-add-SQL-StreamSQL-to-Flink-td9727.html#a9790
> > > > > >>>>
> > > > > >>>> [3] https://www.slideshare.net/tillrohrmann/streaming-
> > analytics-
> > > > > >>>> cep-two-sides-of-the-same-coin
> > > > > >>>>
> > > > > >>>>
> > > > > >>>> Regards,
> > > > > >>>>
> > > > > >>>> Jark Wu
> > > > > >>>>
> > > > > >>>>
> > > > > >>>>
> > > > > >>>> 2017-06-07 13:50 GMT+08:00 Dian Fu <dianfu@apache.org>:
> > > > > >>>>
> > > > > >>>>> Hi everyone,
> > > > > >>>>>
> > > > > >>>>> Flink's CEP library is a great library for complex
event
> > > > processing,
> > > > > >>>>> more
> > > > > >>>>> and more customers are expressing their interests
in it. But
> it
> > > > also
> > > > > >>>>> has
> > > > > >>>>> some limitations that users usually have to
write a lot of
> code
> > > > even
> > > > > >>>>> for a
> > > > > >>>>> very simple pattern match use case as it currently
only
> > supports
> > > > the
> > > > > >>>>> Java
> > > > > >>>>> API.
> > > > > >>>>> We have investigated some popular CEP products
such as esper
> > [1]
> > > > and
> > > > > >>>>> siddhi
> > > > > >>>>> [2] and found that most of these CEP products
support
> SQL-like
> > > > > >>>>> expressions
> > > > > >>>>> such as EPL to describe the match pattern. But
these
> solutions
> > > also
> > > > > >>>>> have
> > > > > >>>>> the drawbacks that the pattern match languages
are not
> standard
> > > > SQL,
> > > > > >>>>> the
> > > > > >>>>> learn curve is steep for users and it's impossible
to
> integrate
> > > > them
> > > > > >>>>> into
> > > > > >>>>> the Flink Table API & SQL.
> > > > > >>>>> We find that Oracle's CEP solution CQL [3] supports
a new
> > pattern
> > > > > >>>>> recognition clause match_recognize which is
a pattern
> > recognition
> > > > > >>>>> clause
> > > > > >>>>> proposed in this paper [4]. It proposes a set
of new syntaxes
> > to
> > > > > define
> > > > > >>>>> match pattern in sql expression. Calcite already
supports
> part
> > of
> > > > > this
> > > > > >>>>> standard [5].  I think it will be of great value
to support
> > > > > expressing
> > > > > >>>>> pattern recognition clause with match_recognize
clause by
> > > > integrating
> > > > > >>>>> it
> > > > > >>>>> with Flink Table API & SQL and the Flink
CEP library. Any
> > > thoughts?
> > > > > >>>>>
> > > > > >>>>> [1] http://www.espertech.com
> > > > > >>>>> [2] https://github.com/wso2/siddhi
> > > > > >>>>> [3]
> > > > > >>>>> https://docs.oracle.com/middleware/1213/eventprocessing/cql-
> > > > > >>>>> reference/GUID-34D4968E-C55A-4BC7-B1CE-C84B202217BD.htm#
> > > CQLLR1531
> > > > > >>>>> [4]
> > > > > >>>>> http://web.cs.ucla.edu/classes/winter17/cs240B/notes/row-pat
> > > > > >>>>> tern-recogniton-11.pdf
> > > > > >>>>> [5] https://issues.apache.org/jira/browse/CALCITE-1570
> > > > > >>>>>
> > > > > >>>>> Best Regards,
> > > > > >>>>> Dian
> > > > > >>>>>
> > > > > >>>>
> > > > > >>>>
> > > > > >>>
> > > > > >>>
> > > > > >>
> > > > > >
> > > > >
> > > >
> > >
> >
>

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