[DISCUSS] FLIP-131: Consolidate the user-facing Dataflow SDKs/APIs (and deprecate the DataSet API)

[Aljoscha Krettek]

Hi Everyone,

my colleagues (in cc) and I would like to propose this FLIP for
discussion. In short, we want to reduce the number of APIs that we have
by deprecating the DataSet API. This is a big step for Flink, that's why
I'm also cross-posting this to the User Mailing List.

FLIP-131: http://s.apache.org/FLIP-131

I'm posting the introduction of the FLIP below but please refer to the
document linked above for the full details:

--
Flink provides three main SDKs/APIs for writing Dataflow Programs: Table
API/SQL, the DataStream API, and the DataSet API. We believe that this
is one API too many and propose to deprecate the DataSet API in favor of
the Table API/SQL and the DataStream API. Of course, this is easier said
than done, so in the following, we will outline why we think that having
too many APIs is detrimental to the project and community. We will then
describe how we can enhance the Table API/SQL and the DataStream API to
subsume the DataSet API's functionality.

In this FLIP, we will not describe all the technical details of how the
Table API/SQL and DataStream will be enhanced. The goal is to achieve
consensus on the idea of deprecating the DataSet API. There will have to
be follow-up FLIPs that describe the necessary changes for the APIs that
we maintain.
--

Please let us know if you have any concerns or comments. Also, please
keep discussion to this ML thread instead of commenting in the Wiki so
that we can have a consistent view of the discussion.

Best,
Aljoscha

[Márton Balassi]

Hi All,

Thanks for the write up and starting the discussion. I am in favor of unifying the APIs the way described in the FLIP and deprecating the DataSet API. I am looking forward to the detailed discussion of the changes necessary.

Best,

Marton

On Wed, Jul 29, 2020 at 12:46 PM Aljoscha Krettek <[hidden email]> wrote:

Hi Everyone,

my colleagues (in cc) and I would like to propose this FLIP for
discussion. In short, we want to reduce the number of APIs that we have
by deprecating the DataSet API. This is a big step for Flink, that's why
I'm also cross-posting this to the User Mailing List.

FLIP-131: http://s.apache.org/FLIP-131

I'm posting the introduction of the FLIP below but please refer to the
document linked above for the full details:

--
Flink provides three main SDKs/APIs for writing Dataflow Programs: Table
API/SQL, the DataStream API, and the DataSet API. We believe that this
is one API too many and propose to deprecate the DataSet API in favor of
the Table API/SQL and the DataStream API. Of course, this is easier said
than done, so in the following, we will outline why we think that having
too many APIs is detrimental to the project and community. We will then
describe how we can enhance the Table API/SQL and the DataStream API to
subsume the DataSet API's functionality.

In this FLIP, we will not describe all the technical details of how the
Table API/SQL and DataStream will be enhanced. The goal is to achieve
consensus on the idea of deprecating the DataSet API. There will have to
be follow-up FLIPs that describe the necessary changes for the APIs that
we maintain.
--

Please let us know if you have any concerns or comments. Also, please
keep discussion to this ML thread instead of commenting in the Wiki so
that we can have a consistent view of the discussion.

Best,
Aljoscha

[Arvid Heise-3]

+1 of getting rid of the DataSet API. Is DataStream#iterate already superseding DataSet iterations or would that also need to be accounted for?

In general, all surviving APIs should also offer a smooth experience for switching back and forth.

On Thu, Jul 30, 2020 at 9:39 AM Márton Balassi <[hidden email]> wrote:

Hi All,

Thanks for the write up and starting the discussion. I am in favor of unifying the APIs the way described in the FLIP and deprecating the DataSet API. I am looking forward to the detailed discussion of the changes necessary.

Best,

Marton

On Wed, Jul 29, 2020 at 12:46 PM Aljoscha Krettek <[hidden email]> wrote:

Hi Everyone,

my colleagues (in cc) and I would like to propose this FLIP for
discussion. In short, we want to reduce the number of APIs that we have
by deprecating the DataSet API. This is a big step for Flink, that's why
I'm also cross-posting this to the User Mailing List.

FLIP-131: http://s.apache.org/FLIP-131

I'm posting the introduction of the FLIP below but please refer to the
document linked above for the full details:

--
Flink provides three main SDKs/APIs for writing Dataflow Programs: Table
API/SQL, the DataStream API, and the DataSet API. We believe that this
is one API too many and propose to deprecate the DataSet API in favor of
the Table API/SQL and the DataStream API. Of course, this is easier said
than done, so in the following, we will outline why we think that having
too many APIs is detrimental to the project and community. We will then
describe how we can enhance the Table API/SQL and the DataStream API to
subsume the DataSet API's functionality.

In this FLIP, we will not describe all the technical details of how the
Table API/SQL and DataStream will be enhanced. The goal is to achieve
consensus on the idea of deprecating the DataSet API. There will have to
be follow-up FLIPs that describe the necessary changes for the APIs that
we maintain.
--

Please let us know if you have any concerns or comments. Also, please
keep discussion to this ML thread instead of commenting in the Wiki so
that we can have a consistent view of the discussion.

Best,
Aljoscha

--

[Kurt Young]

+1, looking forward to the follow up FLIPs. 

On Thu, Jul 30, 2020 at 6:40 PM Arvid Heise <[hidden email]> wrote:

+1 of getting rid of the DataSet API. Is DataStream#iterate already
superseding DataSet iterations or would that also need to be accounted for?

In general, all surviving APIs should also offer a smooth experience for
switching back and forth.

On Thu, Jul 30, 2020 at 9:39 AM Márton Balassi <[hidden email]>
wrote:

> Hi All,
>
> Thanks for the write up and starting the discussion. I am in favor of
> unifying the APIs the way described in the FLIP and deprecating the DataSet
> API. I am looking forward to the detailed discussion of the changes
> necessary.
>
> Best,
> Marton
>
> On Wed, Jul 29, 2020 at 12:46 PM Aljoscha Krettek <[hidden email]>
> wrote:
>
>> Hi Everyone,
>>
>> my colleagues (in cc) and I would like to propose this FLIP for
>> discussion. In short, we want to reduce the number of APIs that we have
>> by deprecating the DataSet API. This is a big step for Flink, that's why
>> I'm also cross-posting this to the User Mailing List.
>>
>> FLIP-131: http://s.apache.org/FLIP-131
>>
>> I'm posting the introduction of the FLIP below but please refer to the
>> document linked above for the full details:
>>
>> --
>> Flink provides three main SDKs/APIs for writing Dataflow Programs: Table
>> API/SQL, the DataStream API, and the DataSet API. We believe that this
>> is one API too many and propose to deprecate the DataSet API in favor of
>> the Table API/SQL and the DataStream API. Of course, this is easier said
>> than done, so in the following, we will outline why we think that having
>> too many APIs is detrimental to the project and community. We will then
>> describe how we can enhance the Table API/SQL and the DataStream API to
>> subsume the DataSet API's functionality.
>>
>> In this FLIP, we will not describe all the technical details of how the
>> Table API/SQL and DataStream will be enhanced. The goal is to achieve
>> consensus on the idea of deprecating the DataSet API. There will have to
>> be follow-up FLIPs that describe the necessary changes for the APIs that
>> we maintain.
>> --
>>
>> Please let us know if you have any concerns or comments. Also, please
>> keep discussion to this ML thread instead of commenting in the Wiki so
>> that we can have a consistent view of the discussion.
>>
>> Best,
>> Aljoscha
>>
>

--

Arvid Heise | Senior Java Developer

<https://www.ververica.com/>

Follow us @VervericaData

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Join Flink Forward <https://flink-forward.org/> - The Apache Flink
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--
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Registered at Amtsgericht Charlottenburg: HRB 158244 B
Managing Directors: Timothy Alexander Steinert, Yip Park Tung Jason, Ji
(Toni) Cheng

[Till Rohrmann]

+1 for this effort. Great to see that we are making progress towards our goal of a truly unified batch and stream processing engine.

Cheers,
Till

On Thu, Jul 30, 2020 at 2:28 PM Kurt Young <[hidden email]> wrote:

+1, looking forward to the follow up FLIPs. 

Best,

Kurt

On Thu, Jul 30, 2020 at 6:40 PM Arvid Heise <[hidden email]> wrote:

+1 of getting rid of the DataSet API. Is DataStream#iterate already
superseding DataSet iterations or would that also need to be accounted for?

In general, all surviving APIs should also offer a smooth experience for
switching back and forth.

On Thu, Jul 30, 2020 at 9:39 AM Márton Balassi <[hidden email]>
wrote:

> Hi All,
>
> Thanks for the write up and starting the discussion. I am in favor of
> unifying the APIs the way described in the FLIP and deprecating the DataSet
> API. I am looking forward to the detailed discussion of the changes
> necessary.
>
> Best,
> Marton
>
> On Wed, Jul 29, 2020 at 12:46 PM Aljoscha Krettek <[hidden email]>
> wrote:
>
>> Hi Everyone,
>>
>> my colleagues (in cc) and I would like to propose this FLIP for
>> discussion. In short, we want to reduce the number of APIs that we have
>> by deprecating the DataSet API. This is a big step for Flink, that's why
>> I'm also cross-posting this to the User Mailing List.
>>
>> FLIP-131: http://s.apache.org/FLIP-131
>>
>> I'm posting the introduction of the FLIP below but please refer to the
>> document linked above for the full details:
>>
>> --
>> Flink provides three main SDKs/APIs for writing Dataflow Programs: Table
>> API/SQL, the DataStream API, and the DataSet API. We believe that this
>> is one API too many and propose to deprecate the DataSet API in favor of
>> the Table API/SQL and the DataStream API. Of course, this is easier said
>> than done, so in the following, we will outline why we think that having
>> too many APIs is detrimental to the project and community. We will then
>> describe how we can enhance the Table API/SQL and the DataStream API to
>> subsume the DataSet API's functionality.
>>
>> In this FLIP, we will not describe all the technical details of how the
>> Table API/SQL and DataStream will be enhanced. The goal is to achieve
>> consensus on the idea of deprecating the DataSet API. There will have to
>> be follow-up FLIPs that describe the necessary changes for the APIs that
>> we maintain.
>> --
>>
>> Please let us know if you have any concerns or comments. Also, please
>> keep discussion to this ML thread instead of commenting in the Wiki so
>> that we can have a consistent view of the discussion.
>>
>> Best,
>> Aljoscha
>>
>

--

Arvid Heise | Senior Java Developer

<https://www.ververica.com/>

Follow us @VervericaData

--

Join Flink Forward <https://flink-forward.org/> - The Apache Flink
Conference

Stream Processing | Event Driven | Real Time

--

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--
Ververica GmbH
Registered at Amtsgericht Charlottenburg: HRB 158244 B
Managing Directors: Timothy Alexander Steinert, Yip Park Tung Jason, Ji
(Toni) Cheng

[Flavio Pompermaier]

Just to contribute to the discussion, when we tried to do the migration we faced some problems that could make migration quite difficult.

1 - It's difficult to test because of https://issues.apache.org/jira/browse/FLINK-18647

2 - missing mapPartition 

3 - missing  <X> DataSet<X> runOperation(CustomUnaryOperation<T, X> operation)

On Thu, Jul 30, 2020 at 12:40 PM Arvid Heise <[hidden email]> wrote:

+1 of getting rid of the DataSet API. Is DataStream#iterate already
superseding DataSet iterations or would that also need to be accounted for?

In general, all surviving APIs should also offer a smooth experience for
switching back and forth.

On Thu, Jul 30, 2020 at 9:39 AM Márton Balassi <[hidden email]>
wrote:

> Hi All,
>
> Thanks for the write up and starting the discussion. I am in favor of
> unifying the APIs the way described in the FLIP and deprecating the DataSet
> API. I am looking forward to the detailed discussion of the changes
> necessary.
>
> Best,
> Marton
>
> On Wed, Jul 29, 2020 at 12:46 PM Aljoscha Krettek <[hidden email]>
> wrote:
>
>> Hi Everyone,
>>
>> my colleagues (in cc) and I would like to propose this FLIP for
>> discussion. In short, we want to reduce the number of APIs that we have
>> by deprecating the DataSet API. This is a big step for Flink, that's why
>> I'm also cross-posting this to the User Mailing List.
>>
>> FLIP-131: http://s.apache.org/FLIP-131
>>
>> I'm posting the introduction of the FLIP below but please refer to the
>> document linked above for the full details:
>>
>> --
>> Flink provides three main SDKs/APIs for writing Dataflow Programs: Table
>> API/SQL, the DataStream API, and the DataSet API. We believe that this
>> is one API too many and propose to deprecate the DataSet API in favor of
>> the Table API/SQL and the DataStream API. Of course, this is easier said
>> than done, so in the following, we will outline why we think that having
>> too many APIs is detrimental to the project and community. We will then
>> describe how we can enhance the Table API/SQL and the DataStream API to
>> subsume the DataSet API's functionality.
>>
>> In this FLIP, we will not describe all the technical details of how the
>> Table API/SQL and DataStream will be enhanced. The goal is to achieve
>> consensus on the idea of deprecating the DataSet API. There will have to
>> be follow-up FLIPs that describe the necessary changes for the APIs that
>> we maintain.
>> --
>>
>> Please let us know if you have any concerns or comments. Also, please
>> keep discussion to this ML thread instead of commenting in the Wiki so
>> that we can have a consistent view of the discussion.
>>
>> Best,
>> Aljoscha
>>
>

--

Arvid Heise | Senior Java Developer

<https://www.ververica.com/>

Follow us @VervericaData

--

Join Flink Forward <https://flink-forward.org/> - The Apache Flink
Conference

Stream Processing | Event Driven | Real Time

--

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--
Ververica GmbH
Registered at Amtsgericht Charlottenburg: HRB 158244 B
Managing Directors: Timothy Alexander Steinert, Yip Park Tung Jason, Ji
(Toni) Cheng

[Seth Wiesman]

+1 Its time to drop DataSet

Flavio, those issues are expected. This FLIP isn't just to drop DataSet but to also add the necessary enhancements to DataStream such that it works well on bounded input.

On Thu, Jul 30, 2020 at 8:49 AM Flavio Pompermaier <[hidden email]> wrote:

Just to contribute to the discussion, when we tried to do the migration we
faced some problems that could make migration quite difficult.
1 - It's difficult to test because of
https://issues.apache.org/jira/browse/FLINK-18647
2 - missing mapPartition
3 - missing  <X> DataSet<X> runOperation(CustomUnaryOperation<T, X>
operation)

On Thu, Jul 30, 2020 at 12:40 PM Arvid Heise <[hidden email]> wrote:

> +1 of getting rid of the DataSet API. Is DataStream#iterate already
> superseding DataSet iterations or would that also need to be accounted for?
>
> In general, all surviving APIs should also offer a smooth experience for
> switching back and forth.
>
> On Thu, Jul 30, 2020 at 9:39 AM Márton Balassi <[hidden email]>
> wrote:
>
> > Hi All,
> >
> > Thanks for the write up and starting the discussion. I am in favor of
> > unifying the APIs the way described in the FLIP and deprecating the
> DataSet
> > API. I am looking forward to the detailed discussion of the changes
> > necessary.
> >
> > Best,
> > Marton
> >
> > On Wed, Jul 29, 2020 at 12:46 PM Aljoscha Krettek <[hidden email]>
> > wrote:
> >
> >> Hi Everyone,
> >>
> >> my colleagues (in cc) and I would like to propose this FLIP for
> >> discussion. In short, we want to reduce the number of APIs that we have
> >> by deprecating the DataSet API. This is a big step for Flink, that's why
> >> I'm also cross-posting this to the User Mailing List.
> >>
> >> FLIP-131: http://s.apache.org/FLIP-131
> >>
> >> I'm posting the introduction of the FLIP below but please refer to the
> >> document linked above for the full details:
> >>
> >> --
> >> Flink provides three main SDKs/APIs for writing Dataflow Programs: Table
> >> API/SQL, the DataStream API, and the DataSet API. We believe that this
> >> is one API too many and propose to deprecate the DataSet API in favor of
> >> the Table API/SQL and the DataStream API. Of course, this is easier said
> >> than done, so in the following, we will outline why we think that having
> >> too many APIs is detrimental to the project and community. We will then
> >> describe how we can enhance the Table API/SQL and the DataStream API to
> >> subsume the DataSet API's functionality.
> >>
> >> In this FLIP, we will not describe all the technical details of how the
> >> Table API/SQL and DataStream will be enhanced. The goal is to achieve
> >> consensus on the idea of deprecating the DataSet API. There will have to
> >> be follow-up FLIPs that describe the necessary changes for the APIs that
> >> we maintain.
> >> --
> >>
> >> Please let us know if you have any concerns or comments. Also, please
> >> keep discussion to this ML thread instead of commenting in the Wiki so
> >> that we can have a consistent view of the discussion.
> >>
> >> Best,
> >> Aljoscha
> >>
> >
>
> --
>
> Arvid Heise | Senior Java Developer
>
> <https://www.ververica.com/>
>
> Follow us @VervericaData
>
> --
>
> Join Flink Forward <https://flink-forward.org/> - The Apache Flink
> Conference
>
> Stream Processing | Event Driven | Real Time
>
> --
>
> Ververica GmbH | Invalidenstrasse 115, 10115 Berlin, Germany
>
> --
> Ververica GmbH
> Registered at Amtsgericht Charlottenburg: HRB 158244 B
> Managing Directors: Timothy Alexander Steinert, Yip Park Tung Jason, Ji
> (Toni) Cheng

[Flavio Pompermaier]

I just wanted to be propositive about missing api.. :D

On Thu, Jul 30, 2020 at 4:29 PM Seth Wiesman <[hidden email]> wrote:

+1 Its time to drop DataSet

Flavio, those issues are expected. This FLIP isn't just to drop DataSet but to also add the necessary enhancements to DataStream such that it works well on bounded input.

On Thu, Jul 30, 2020 at 8:49 AM Flavio Pompermaier <[hidden email]> wrote:

Just to contribute to the discussion, when we tried to do the migration we
faced some problems that could make migration quite difficult.
1 - It's difficult to test because of
https://issues.apache.org/jira/browse/FLINK-18647
2 - missing mapPartition
3 - missing  <X> DataSet<X> runOperation(CustomUnaryOperation<T, X>
operation)

On Thu, Jul 30, 2020 at 12:40 PM Arvid Heise <[hidden email]> wrote:

> +1 of getting rid of the DataSet API. Is DataStream#iterate already
> superseding DataSet iterations or would that also need to be accounted for?
>
> In general, all surviving APIs should also offer a smooth experience for
> switching back and forth.
>
> On Thu, Jul 30, 2020 at 9:39 AM Márton Balassi <[hidden email]>
> wrote:
>
> > Hi All,
> >
> > Thanks for the write up and starting the discussion. I am in favor of
> > unifying the APIs the way described in the FLIP and deprecating the
> DataSet
> > API. I am looking forward to the detailed discussion of the changes
> > necessary.
> >
> > Best,
> > Marton
> >
> > On Wed, Jul 29, 2020 at 12:46 PM Aljoscha Krettek <[hidden email]>
> > wrote:
> >
> >> Hi Everyone,
> >>
> >> my colleagues (in cc) and I would like to propose this FLIP for
> >> discussion. In short, we want to reduce the number of APIs that we have
> >> by deprecating the DataSet API. This is a big step for Flink, that's why
> >> I'm also cross-posting this to the User Mailing List.
> >>
> >> FLIP-131: http://s.apache.org/FLIP-131
> >>
> >> I'm posting the introduction of the FLIP below but please refer to the
> >> document linked above for the full details:
> >>
> >> --
> >> Flink provides three main SDKs/APIs for writing Dataflow Programs: Table
> >> API/SQL, the DataStream API, and the DataSet API. We believe that this
> >> is one API too many and propose to deprecate the DataSet API in favor of
> >> the Table API/SQL and the DataStream API. Of course, this is easier said
> >> than done, so in the following, we will outline why we think that having
> >> too many APIs is detrimental to the project and community. We will then
> >> describe how we can enhance the Table API/SQL and the DataStream API to
> >> subsume the DataSet API's functionality.
> >>
> >> In this FLIP, we will not describe all the technical details of how the
> >> Table API/SQL and DataStream will be enhanced. The goal is to achieve
> >> consensus on the idea of deprecating the DataSet API. There will have to
> >> be follow-up FLIPs that describe the necessary changes for the APIs that
> >> we maintain.
> >> --
> >>
> >> Please let us know if you have any concerns or comments. Also, please
> >> keep discussion to this ML thread instead of commenting in the Wiki so
> >> that we can have a consistent view of the discussion.
> >>
> >> Best,
> >> Aljoscha
> >>
> >
>
> --
>
> Arvid Heise | Senior Java Developer
>
> <https://www.ververica.com/>
>
> Follow us @VervericaData
>
> --
>
> Join Flink Forward <https://flink-forward.org/> - The Apache Flink
> Conference
>
> Stream Processing | Event Driven | Real Time
>
> --
>
> Ververica GmbH | Invalidenstrasse 115, 10115 Berlin, Germany
>
> --
> Ververica GmbH
> Registered at Amtsgericht Charlottenburg: HRB 158244 B
> Managing Directors: Timothy Alexander Steinert, Yip Park Tung Jason, Ji
> (Toni) Cheng

[Aljoscha Krettek]

That is good input! I was not aware that anyone was actually using
`runCustomOperation()`. Out of curiosity, what are you using that for?

We have definitely thought about the first two points you mentioned,
though. Especially processing-time will make it tricky to define unified
execution semantics.

Best,
Aljoscha

On 30.07.20 17:10, Flavio Pompermaier wrote:

> I just wanted to be propositive about missing api.. :D
>
> On Thu, Jul 30, 2020 at 4:29 PM Seth Wiesman <[hidden email]> wrote:
>
>> +1 Its time to drop DataSet
>>
>> Flavio, those issues are expected. This FLIP isn't just to drop DataSet
>> but to also add the necessary enhancements to DataStream such that it works
>> well on bounded input.
>>
>> On Thu, Jul 30, 2020 at 8:49 AM Flavio Pompermaier <[hidden email]>
>> wrote:
>>
>>> Just to contribute to the discussion, when we tried to do the migration we
>>> faced some problems that could make migration quite difficult.
>>> 1 - It's difficult to test because of
>>> https://issues.apache.org/jira/browse/FLINK-18647
>>> 2 - missing mapPartition
>>> 3 - missing  <X> DataSet<X> runOperation(CustomUnaryOperation<T, X>
>>> operation)
>>>
>>> On Thu, Jul 30, 2020 at 12:40 PM Arvid Heise <[hidden email]> wrote:
>>>
>>>> +1 of getting rid of the DataSet API. Is DataStream#iterate already
>>>> superseding DataSet iterations or would that also need to be accounted
>>> for?
>>>>
>>>> In general, all surviving APIs should also offer a smooth experience for
>>>> switching back and forth.
>>>>
>>>> On Thu, Jul 30, 2020 at 9:39 AM Márton Balassi <
>>> [hidden email]>
>>>> wrote:
>>>>
>>>>> Hi All,
>>>>>
>>>>> Thanks for the write up and starting the discussion. I am in favor of
>>>>> unifying the APIs the way described in the FLIP and deprecating the
>>>> DataSet
>>>>> API. I am looking forward to the detailed discussion of the changes
>>>>> necessary.
>>>>>
>>>>> Best,
>>>>> Marton
>>>>>
>>>>> On Wed, Jul 29, 2020 at 12:46 PM Aljoscha Krettek <
>>> [hidden email]>
>>>>> wrote:
>>>>>
>>>>>> Hi Everyone,
>>>>>>
>>>>>> my colleagues (in cc) and I would like to propose this FLIP for
>>>>>> discussion. In short, we want to reduce the number of APIs that we
>>> have
>>>>>> by deprecating the DataSet API. This is a big step for Flink, that's
>>> why
>>>>>> I'm also cross-posting this to the User Mailing List.
>>>>>>
>>>>>> FLIP-131: http://s.apache.org/FLIP-131
>>>>>>
>>>>>> I'm posting the introduction of the FLIP below but please refer to
>>> the
>>>>>> document linked above for the full details:
>>>>>>
>>>>>> --
>>>>>> Flink provides three main SDKs/APIs for writing Dataflow Programs:
>>> Table
>>>>>> API/SQL, the DataStream API, and the DataSet API. We believe that
>>> this
>>>>>> is one API too many and propose to deprecate the DataSet API in
>>> favor of
>>>>>> the Table API/SQL and the DataStream API. Of course, this is easier
>>> said
>>>>>> than done, so in the following, we will outline why we think that
>>> having
>>>>>> too many APIs is detrimental to the project and community. We will
>>> then
>>>>>> describe how we can enhance the Table API/SQL and the DataStream API
>>> to
>>>>>> subsume the DataSet API's functionality.
>>>>>>
>>>>>> In this FLIP, we will not describe all the technical details of how
>>> the
>>>>>> Table API/SQL and DataStream will be enhanced. The goal is to achieve
>>>>>> consensus on the idea of deprecating the DataSet API. There will
>>> have to
>>>>>> be follow-up FLIPs that describe the necessary changes for the APIs
>>> that
>>>>>> we maintain.
>>>>>> --
>>>>>>
>>>>>> Please let us know if you have any concerns or comments. Also, please
>>>>>> keep discussion to this ML thread instead of commenting in the Wiki
>>> so
>>>>>> that we can have a consistent view of the discussion.
>>>>>>
>>>>>> Best,
>>>>>> Aljoscha
>>>>>>
>>>>>
>>>>
>>>> --
>>>>
>>>> Arvid Heise | Senior Java Developer
>>>>
>>>> <https://www.ververica.com/>
>>>>
>>>> Follow us @VervericaData
>>>>
>>>> --
>>>>
>>>> Join Flink Forward <https://flink-forward.org/> - The Apache Flink
>>>> Conference
>>>>
>>>> Stream Processing | Event Driven | Real Time
>>>>
>>>> --
>>>>
>>>> Ververica GmbH | Invalidenstrasse 115, 10115 Berlin, Germany
>>>>
>>>> --
>>>> Ververica GmbH
>>>> Registered at Amtsgericht Charlottenburg: HRB 158244 B
>>>> Managing Directors: Timothy Alexander Steinert, Yip Park Tung Jason, Ji
>>>> (Toni) Cheng
>>
>>
>

[Flavio Pompermaier]

We use runCustomOperation to group a set of operators and into a single functional unit, just to make the code more modular..

It's very comfortable indeed.

On Thu, Jul 30, 2020 at 5:20 PM Aljoscha Krettek <[hidden email]> wrote:

That is good input! I was not aware that anyone was actually using
`runCustomOperation()`. Out of curiosity, what are you using that for?

We have definitely thought about the first two points you mentioned,
though. Especially processing-time will make it tricky to define unified
execution semantics.

Best,
Aljoscha

On 30.07.20 17:10, Flavio Pompermaier wrote:
> I just wanted to be propositive about missing api.. :D
>
> On Thu, Jul 30, 2020 at 4:29 PM Seth Wiesman <[hidden email]> wrote:
>
>> +1 Its time to drop DataSet
>>
>> Flavio, those issues are expected. This FLIP isn't just to drop DataSet
>> but to also add the necessary enhancements to DataStream such that it works
>> well on bounded input.
>>
>> On Thu, Jul 30, 2020 at 8:49 AM Flavio Pompermaier <[hidden email]>
>> wrote:
>>
>>> Just to contribute to the discussion, when we tried to do the migration we
>>> faced some problems that could make migration quite difficult.
>>> 1 - It's difficult to test because of
>>> https://issues.apache.org/jira/browse/FLINK-18647
>>> 2 - missing mapPartition
>>> 3 - missing  <X> DataSet<X> runOperation(CustomUnaryOperation<T, X>
>>> operation)
>>>
>>> On Thu, Jul 30, 2020 at 12:40 PM Arvid Heise <[hidden email]> wrote:
>>>
>>>> +1 of getting rid of the DataSet API. Is DataStream#iterate already
>>>> superseding DataSet iterations or would that also need to be accounted
>>> for?
>>>>
>>>> In general, all surviving APIs should also offer a smooth experience for
>>>> switching back and forth.
>>>>
>>>> On Thu, Jul 30, 2020 at 9:39 AM Márton Balassi <
>>> [hidden email]>
>>>> wrote:
>>>>
>>>>> Hi All,
>>>>>
>>>>> Thanks for the write up and starting the discussion. I am in favor of
>>>>> unifying the APIs the way described in the FLIP and deprecating the
>>>> DataSet
>>>>> API. I am looking forward to the detailed discussion of the changes
>>>>> necessary.
>>>>>
>>>>> Best,
>>>>> Marton
>>>>>
>>>>> On Wed, Jul 29, 2020 at 12:46 PM Aljoscha Krettek <
>>> [hidden email]>
>>>>> wrote:
>>>>>
>>>>>> Hi Everyone,
>>>>>>
>>>>>> my colleagues (in cc) and I would like to propose this FLIP for
>>>>>> discussion. In short, we want to reduce the number of APIs that we
>>> have
>>>>>> by deprecating the DataSet API. This is a big step for Flink, that's
>>> why
>>>>>> I'm also cross-posting this to the User Mailing List.
>>>>>>
>>>>>> FLIP-131: http://s.apache.org/FLIP-131
>>>>>>
>>>>>> I'm posting the introduction of the FLIP below but please refer to
>>> the
>>>>>> document linked above for the full details:
>>>>>>
>>>>>> --
>>>>>> Flink provides three main SDKs/APIs for writing Dataflow Programs:
>>> Table
>>>>>> API/SQL, the DataStream API, and the DataSet API. We believe that
>>> this
>>>>>> is one API too many and propose to deprecate the DataSet API in
>>> favor of
>>>>>> the Table API/SQL and the DataStream API. Of course, this is easier
>>> said
>>>>>> than done, so in the following, we will outline why we think that
>>> having
>>>>>> too many APIs is detrimental to the project and community. We will
>>> then
>>>>>> describe how we can enhance the Table API/SQL and the DataStream API
>>> to
>>>>>> subsume the DataSet API's functionality.
>>>>>>
>>>>>> In this FLIP, we will not describe all the technical details of how
>>> the
>>>>>> Table API/SQL and DataStream will be enhanced. The goal is to achieve
>>>>>> consensus on the idea of deprecating the DataSet API. There will
>>> have to
>>>>>> be follow-up FLIPs that describe the necessary changes for the APIs
>>> that
>>>>>> we maintain.
>>>>>> --
>>>>>>
>>>>>> Please let us know if you have any concerns or comments. Also, please
>>>>>> keep discussion to this ML thread instead of commenting in the Wiki
>>> so
>>>>>> that we can have a consistent view of the discussion.
>>>>>>
>>>>>> Best,
>>>>>> Aljoscha
>>>>>>
>>>>>
>>>>
>>>> --
>>>>
>>>> Arvid Heise | Senior Java Developer
>>>>
>>>> <https://www.ververica.com/>
>>>>
>>>> Follow us @VervericaData
>>>>
>>>> --
>>>>
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>>>> Conference
>>>>
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>>
>>
>