Re: [DISCUSS] Flink Python User-Defined Function for Table API

[Aljoscha Krettek]

Hi,

Thanks for the quick response! I think this looks good now and it should be 
something that everyone can agree on as a first step.

Best,
Aljoscha

> On 6. Sep 2019, at 12:22, Dian Fu  wrote:
> 
> Hi all,
> 
> I have updated the FLIP and removed content relate to UDAF and also changed 
> the title of the FLIP to "Flink Python User-Defined Stateless Function for 
> Table". Does it make sense to you? 
> 
> Regards,
> Dian
> 
>> 在 2019年9月6日，下午6:09，Dian Fu  写道：
>> 
>> Hi all,
>> 
>> Thanks a lot for the discussion here. It makes sense to limit the scope of 
>> this FLIP to only ScalarFunction. I'll update the FLIP and remove the 
>> content relating to UDAF.
>> 
>> Thanks,
>> Dian
>> 
>>> 在 2019年9月6日，下午6:02，jincheng sun  写道：
>>> 
>>> Hi，
>>> 
>>> Sure, for ensure the 1.10 relesae of flink, let's split the FLIPs, and
>>> FLIP-58 only do the stateless part.
>>> 
>>> Cheers,
>>> Jincheng
>>> 
>>> Aljoscha Krettek  于2019年9月6日周五 下午5:53写道：
>>> 
 Hi,
 
 Regarding stateful functions and MapView/DataView/ListView: I think it’s
 best to keep that for a later FLIP and focus on a more basic version.
 Supporting stateful functions, especially with MapView can potentially be
 very slow so we have to see what we can do there.
 
 For the method names, I don’t know. If FLIP-64 passes they have to be
 changed. So we could use the final names right away, but I’m also fine with
 using the old method names for now.
 
 Best,
 Aljoscha
 
> On 5. Sep 2019, at 12:40, jincheng sun  wrote:
> 
> Hi Aljoscha,
> 
> Thanks for your comments!
> 
> Regarding to the FLIP scope, it seems that we have agreed on the design
 of
> the stateless function support.
> What do you think about starting the development of the stateless
 function
> support firstly and continue the discussion of stateful function support?
> Or you think we should split the current FLIP into two FLIPs and discuss
> the stateful function support in another thread?
> 
> Currently, the Python DataView/MapView/ListView interfaces design follow
> the Java/Scala naming conversions.
> Of couse, We can continue to discuss whether there are better solutions,
> i.e. using annotations.
> 
> Regarding to the magic logic to support DataView/MapView/ListView, it
 will
> be done by the framework and is transparent for users.
> Per my understanding, the magic logic is unavoidable no matter what the
> interfaces will be.
> 
> Regarding to the catalog support of python function:1) If it's stored in
> memory as temporary object, just as you said, users can call
> TableEnvironment.register_function(will change to
> register_temporary_function in FLIP-64)
> 2) If it's persisted in external storage, users can call
> Catalog.create_function. There will be no API change per my
 understanding.
> 
> What do you think?
> Best,Jincheng
> 
> Aljoscha Krettek  于2019年9月5日周四 下午5:32写道：
> 
>> Hi,
>> 
>> Another thing to consider is the Scope of the FLIP. Currently, we try to
>> support (stateful) AggregateFunctions. I have some concerns about
 whether
>> or not DataView/MapView/ListView is a good interface because it requires
>> quite some magic from the runners to make it work, such as messing with
 the
>> TypeInformation and injecting objects at runtime. If the FLIP aims for
 the
>> minimum of ScalarFunctions and the whole execution harness, that should
 be
>> easier to agree on.
>> 
>> Another point is the naming of the new methods. I think Timo hinted at
 the
>> fact that we have to consider catalog support for functions. There is
>> ongoing work about differentiating between temporary objects and objects
>> that are stored in a catalog (FLIP-64 [1]). With this in mind, the
 method
>> for registering functions should be called register_temporary_function()
>> and so on. Unless we want to already think about mixing Python and Java
>> functions in the catalog, which is outside the scope of this FLIP, I
 think.
>> 
>> Best,
>> Aljoscha
>> 
>> [1]
>> 
 https://cwiki.apache.org/confluence/display/FLINK/FLIP-64%3A+Support+for+Temporary+Objects+in+Table+module
>> 
>> 
>>> On 5. Sep 2019, at 05:01, jincheng sun 
 wrote:
>>> 
>>> Hi Aljoscha,
>>> 
>>> That's a good points, so far, most of the code will live in
 flink-python
>>> module, and the rules and relNodes will be put into the both blink and
>>> flink planner modules, some of the common interface of required by
>> planners
>>> will be placed in flink-table-common. I think you are right, we should
>> try
>>> to ensure the changes of this feature is minimal.  For more detail we
>> would
>>> follow this principle when review the PRs.
>>> 
>>> Great 

Re: [DISCUSS] Flink Python User-Defined Function for Table API

[Dian Fu]

Hi all,

I have updated the FLIP and removed content relate to UDAF and also changed the 
title of the FLIP to "Flink Python User-Defined Stateless Function for Table". 
Does it make sense to you? 

Regards,
Dian

> 在 2019年9月6日，下午6:09，Dian Fu  写道：
> 
> Hi all,
> 
> Thanks a lot for the discussion here. It makes sense to limit the scope of 
> this FLIP to only ScalarFunction. I'll update the FLIP and remove the content 
> relating to UDAF.
> 
> Thanks,
> Dian
> 
>> 在 2019年9月6日，下午6:02，jincheng sun  写道：
>> 
>> Hi，
>> 
>> Sure, for ensure the 1.10 relesae of flink, let's split the FLIPs, and
>> FLIP-58 only do the stateless part.
>> 
>> Cheers,
>> Jincheng
>> 
>> Aljoscha Krettek  于2019年9月6日周五 下午5:53写道：
>> 
>>> Hi,
>>> 
>>> Regarding stateful functions and MapView/DataView/ListView: I think it’s
>>> best to keep that for a later FLIP and focus on a more basic version.
>>> Supporting stateful functions, especially with MapView can potentially be
>>> very slow so we have to see what we can do there.
>>> 
>>> For the method names, I don’t know. If FLIP-64 passes they have to be
>>> changed. So we could use the final names right away, but I’m also fine with
>>> using the old method names for now.
>>> 
>>> Best,
>>> Aljoscha
>>> 
 On 5. Sep 2019, at 12:40, jincheng sun  wrote:
 
 Hi Aljoscha,
 
 Thanks for your comments!
 
 Regarding to the FLIP scope, it seems that we have agreed on the design
>>> of
 the stateless function support.
 What do you think about starting the development of the stateless
>>> function
 support firstly and continue the discussion of stateful function support?
 Or you think we should split the current FLIP into two FLIPs and discuss
 the stateful function support in another thread?
 
 Currently, the Python DataView/MapView/ListView interfaces design follow
 the Java/Scala naming conversions.
 Of couse, We can continue to discuss whether there are better solutions,
 i.e. using annotations.
 
 Regarding to the magic logic to support DataView/MapView/ListView, it
>>> will
 be done by the framework and is transparent for users.
 Per my understanding, the magic logic is unavoidable no matter what the
 interfaces will be.
 
 Regarding to the catalog support of python function:1) If it's stored in
 memory as temporary object, just as you said, users can call
 TableEnvironment.register_function(will change to
 register_temporary_function in FLIP-64)
 2) If it's persisted in external storage, users can call
 Catalog.create_function. There will be no API change per my
>>> understanding.
 
 What do you think?
 Best,Jincheng
 
 Aljoscha Krettek  于2019年9月5日周四 下午5:32写道：
 
> Hi,
> 
> Another thing to consider is the Scope of the FLIP. Currently, we try to
> support (stateful) AggregateFunctions. I have some concerns about
>>> whether
> or not DataView/MapView/ListView is a good interface because it requires
> quite some magic from the runners to make it work, such as messing with
>>> the
> TypeInformation and injecting objects at runtime. If the FLIP aims for
>>> the
> minimum of ScalarFunctions and the whole execution harness, that should
>>> be
> easier to agree on.
> 
> Another point is the naming of the new methods. I think Timo hinted at
>>> the
> fact that we have to consider catalog support for functions. There is
> ongoing work about differentiating between temporary objects and objects
> that are stored in a catalog (FLIP-64 [1]). With this in mind, the
>>> method
> for registering functions should be called register_temporary_function()
> and so on. Unless we want to already think about mixing Python and Java
> functions in the catalog, which is outside the scope of this FLIP, I
>>> think.
> 
> Best,
> Aljoscha
> 
> [1]
> 
>>> https://cwiki.apache.org/confluence/display/FLINK/FLIP-64%3A+Support+for+Temporary+Objects+in+Table+module
> 
> 
>> On 5. Sep 2019, at 05:01, jincheng sun 
>>> wrote:
>> 
>> Hi Aljoscha,
>> 
>> That's a good points, so far, most of the code will live in
>>> flink-python
>> module, and the rules and relNodes will be put into the both blink and
>> flink planner modules, some of the common interface of required by
> planners
>> will be placed in flink-table-common. I think you are right, we should
> try
>> to ensure the changes of this feature is minimal.  For more detail we
> would
>> follow this principle when review the PRs.
>> 
>> Great thanks for your questions and remind!
>> 
>> Best,
>> Jincheng
>> 
>> 
>> Aljoscha Krettek  于2019年9月4日周三 下午8:58写道：
>> 
>>> Hi,
>>> 
>>> Things looks interesting so far!
>>> 
>>> I had one question: Where will most of the support code for this live?
>>> Will this add the required code to 

Re: [DISCUSS] Flink Python User-Defined Function for Table API

[Dian Fu]

Hi all,

Thanks a lot for the discussion here. It makes sense to limit the scope of this 
FLIP to only ScalarFunction. I'll update the FLIP and remove the content 
relating to UDAF.

Thanks,
Dian

> 在 2019年9月6日，下午6:02，jincheng sun  写道：
> 
> Hi，
> 
> Sure, for ensure the 1.10 relesae of flink, let's split the FLIPs, and
> FLIP-58 only do the stateless part.
> 
> Cheers,
> Jincheng
> 
> Aljoscha Krettek  于2019年9月6日周五 下午5:53写道：
> 
>> Hi,
>> 
>> Regarding stateful functions and MapView/DataView/ListView: I think it’s
>> best to keep that for a later FLIP and focus on a more basic version.
>> Supporting stateful functions, especially with MapView can potentially be
>> very slow so we have to see what we can do there.
>> 
>> For the method names, I don’t know. If FLIP-64 passes they have to be
>> changed. So we could use the final names right away, but I’m also fine with
>> using the old method names for now.
>> 
>> Best,
>> Aljoscha
>> 
>>> On 5. Sep 2019, at 12:40, jincheng sun  wrote:
>>> 
>>> Hi Aljoscha,
>>> 
>>> Thanks for your comments!
>>> 
>>> Regarding to the FLIP scope, it seems that we have agreed on the design
>> of
>>> the stateless function support.
>>> What do you think about starting the development of the stateless
>> function
>>> support firstly and continue the discussion of stateful function support?
>>> Or you think we should split the current FLIP into two FLIPs and discuss
>>> the stateful function support in another thread?
>>> 
>>> Currently, the Python DataView/MapView/ListView interfaces design follow
>>> the Java/Scala naming conversions.
>>> Of couse, We can continue to discuss whether there are better solutions,
>>> i.e. using annotations.
>>> 
>>> Regarding to the magic logic to support DataView/MapView/ListView, it
>> will
>>> be done by the framework and is transparent for users.
>>> Per my understanding, the magic logic is unavoidable no matter what the
>>> interfaces will be.
>>> 
>>> Regarding to the catalog support of python function:1) If it's stored in
>>> memory as temporary object, just as you said, users can call
>>> TableEnvironment.register_function(will change to
>>> register_temporary_function in FLIP-64)
>>> 2) If it's persisted in external storage, users can call
>>> Catalog.create_function. There will be no API change per my
>> understanding.
>>> 
>>> What do you think?
>>> Best,Jincheng
>>> 
>>> Aljoscha Krettek  于2019年9月5日周四 下午5:32写道：
>>> 
 Hi,
 
 Another thing to consider is the Scope of the FLIP. Currently, we try to
 support (stateful) AggregateFunctions. I have some concerns about
>> whether
 or not DataView/MapView/ListView is a good interface because it requires
 quite some magic from the runners to make it work, such as messing with
>> the
 TypeInformation and injecting objects at runtime. If the FLIP aims for
>> the
 minimum of ScalarFunctions and the whole execution harness, that should
>> be
 easier to agree on.
 
 Another point is the naming of the new methods. I think Timo hinted at
>> the
 fact that we have to consider catalog support for functions. There is
 ongoing work about differentiating between temporary objects and objects
 that are stored in a catalog (FLIP-64 [1]). With this in mind, the
>> method
 for registering functions should be called register_temporary_function()
 and so on. Unless we want to already think about mixing Python and Java
 functions in the catalog, which is outside the scope of this FLIP, I
>> think.
 
 Best,
 Aljoscha
 
 [1]
 
>> https://cwiki.apache.org/confluence/display/FLINK/FLIP-64%3A+Support+for+Temporary+Objects+in+Table+module
 
 
> On 5. Sep 2019, at 05:01, jincheng sun 
>> wrote:
> 
> Hi Aljoscha,
> 
> That's a good points, so far, most of the code will live in
>> flink-python
> module, and the rules and relNodes will be put into the both blink and
> flink planner modules, some of the common interface of required by
 planners
> will be placed in flink-table-common. I think you are right, we should
 try
> to ensure the changes of this feature is minimal.  For more detail we
 would
> follow this principle when review the PRs.
> 
> Great thanks for your questions and remind!
> 
> Best,
> Jincheng
> 
> 
> Aljoscha Krettek  于2019年9月4日周三 下午8:58写道：
> 
>> Hi,
>> 
>> Things looks interesting so far!
>> 
>> I had one question: Where will most of the support code for this live?
>> Will this add the required code to flink-table-common or the different
>> runners? Can we implement this in such a way that only a minimal
>> amount
 of
>> support code is required in the parts of the Table API (and Table API
>> runners) that  are not python specific?
>> 
>> Best,
>> Aljoscha
>> 
>>> On 4. Sep 2019, at 14:14, Timo Walther  wrote:
>>> 
>>> Hi Jincheng,
>>> 
>>> 2. 

Re: [DISCUSS] Flink Python User-Defined Function for Table API

[jincheng sun]

Hi，

Sure, for ensure the 1.10 relesae of flink, let's split the FLIPs, and
FLIP-58 only do the stateless part.

Cheers,
Jincheng

Aljoscha Krettek  于2019年9月6日周五 下午5:53写道：

> Hi,
>
> Regarding stateful functions and MapView/DataView/ListView: I think it’s
> best to keep that for a later FLIP and focus on a more basic version.
> Supporting stateful functions, especially with MapView can potentially be
> very slow so we have to see what we can do there.
>
> For the method names, I don’t know. If FLIP-64 passes they have to be
> changed. So we could use the final names right away, but I’m also fine with
> using the old method names for now.
>
> Best,
> Aljoscha
>
> > On 5. Sep 2019, at 12:40, jincheng sun  wrote:
> >
> > Hi Aljoscha,
> >
> > Thanks for your comments!
> >
> > Regarding to the FLIP scope, it seems that we have agreed on the design
> of
> > the stateless function support.
> > What do you think about starting the development of the stateless
> function
> > support firstly and continue the discussion of stateful function support?
> > Or you think we should split the current FLIP into two FLIPs and discuss
> > the stateful function support in another thread?
> >
> > Currently, the Python DataView/MapView/ListView interfaces design follow
> > the Java/Scala naming conversions.
> > Of couse, We can continue to discuss whether there are better solutions,
> > i.e. using annotations.
> >
> > Regarding to the magic logic to support DataView/MapView/ListView, it
> will
> > be done by the framework and is transparent for users.
> > Per my understanding, the magic logic is unavoidable no matter what the
> > interfaces will be.
> >
> > Regarding to the catalog support of python function:1) If it's stored in
> > memory as temporary object, just as you said, users can call
> > TableEnvironment.register_function(will change to
> > register_temporary_function in FLIP-64)
> > 2) If it's persisted in external storage, users can call
> > Catalog.create_function. There will be no API change per my
> understanding.
> >
> > What do you think?
> > Best,Jincheng
> >
> > Aljoscha Krettek  于2019年9月5日周四 下午5:32写道：
> >
> >> Hi,
> >>
> >> Another thing to consider is the Scope of the FLIP. Currently, we try to
> >> support (stateful) AggregateFunctions. I have some concerns about
> whether
> >> or not DataView/MapView/ListView is a good interface because it requires
> >> quite some magic from the runners to make it work, such as messing with
> the
> >> TypeInformation and injecting objects at runtime. If the FLIP aims for
> the
> >> minimum of ScalarFunctions and the whole execution harness, that should
> be
> >> easier to agree on.
> >>
> >> Another point is the naming of the new methods. I think Timo hinted at
> the
> >> fact that we have to consider catalog support for functions. There is
> >> ongoing work about differentiating between temporary objects and objects
> >> that are stored in a catalog (FLIP-64 [1]). With this in mind, the
> method
> >> for registering functions should be called register_temporary_function()
> >> and so on. Unless we want to already think about mixing Python and Java
> >> functions in the catalog, which is outside the scope of this FLIP, I
> think.
> >>
> >> Best,
> >> Aljoscha
> >>
> >> [1]
> >>
> https://cwiki.apache.org/confluence/display/FLINK/FLIP-64%3A+Support+for+Temporary+Objects+in+Table+module
> >>
> >>
> >>> On 5. Sep 2019, at 05:01, jincheng sun 
> wrote:
> >>>
> >>> Hi Aljoscha,
> >>>
> >>> That's a good points, so far, most of the code will live in
> flink-python
> >>> module, and the rules and relNodes will be put into the both blink and
> >>> flink planner modules, some of the common interface of required by
> >> planners
> >>> will be placed in flink-table-common. I think you are right, we should
> >> try
> >>> to ensure the changes of this feature is minimal.  For more detail we
> >> would
> >>> follow this principle when review the PRs.
> >>>
> >>> Great thanks for your questions and remind!
> >>>
> >>> Best,
> >>> Jincheng
> >>>
> >>>
> >>> Aljoscha Krettek  于2019年9月4日周三 下午8:58写道：
> >>>
>  Hi,
> 
>  Things looks interesting so far!
> 
>  I had one question: Where will most of the support code for this live?
>  Will this add the required code to flink-table-common or the different
>  runners? Can we implement this in such a way that only a minimal
> amount
> >> of
>  support code is required in the parts of the Table API (and Table API
>  runners) that  are not python specific?
> 
>  Best,
>  Aljoscha
> 
> > On 4. Sep 2019, at 14:14, Timo Walther  wrote:
> >
> > Hi Jincheng,
> >
> > 2. Serializability of functions: "#2 is very convenient for users"
> >> means
>  only until they have the first backwards-compatibility issue, after
> that
>  they will find it not so convinient anymore and will ask why the
> >> framework
>  allowed storing such objects in a persistent storage. I don't want to
> 

Re: [DISCUSS] Flink Python User-Defined Function for Table API

[Aljoscha Krettek]

Hi,

Regarding stateful functions and MapView/DataView/ListView: I think it’s best 
to keep that for a later FLIP and focus on a more basic version. Supporting 
stateful functions, especially with MapView can potentially be very slow so we 
have to see what we can do there.

For the method names, I don’t know. If FLIP-64 passes they have to be changed. 
So we could use the final names right away, but I’m also fine with using the 
old method names for now.

Best,
Aljoscha

> On 5. Sep 2019, at 12:40, jincheng sun  wrote:
> 
> Hi Aljoscha,
> 
> Thanks for your comments!
> 
> Regarding to the FLIP scope, it seems that we have agreed on the design of
> the stateless function support.
> What do you think about starting the development of the stateless function
> support firstly and continue the discussion of stateful function support?
> Or you think we should split the current FLIP into two FLIPs and discuss
> the stateful function support in another thread?
> 
> Currently, the Python DataView/MapView/ListView interfaces design follow
> the Java/Scala naming conversions.
> Of couse, We can continue to discuss whether there are better solutions,
> i.e. using annotations.
> 
> Regarding to the magic logic to support DataView/MapView/ListView, it will
> be done by the framework and is transparent for users.
> Per my understanding, the magic logic is unavoidable no matter what the
> interfaces will be.
> 
> Regarding to the catalog support of python function:1) If it's stored in
> memory as temporary object, just as you said, users can call
> TableEnvironment.register_function(will change to
> register_temporary_function in FLIP-64)
> 2) If it's persisted in external storage, users can call
> Catalog.create_function. There will be no API change per my understanding.
> 
> What do you think?
> Best,Jincheng
> 
> Aljoscha Krettek  于2019年9月5日周四 下午5:32写道：
> 
>> Hi,
>> 
>> Another thing to consider is the Scope of the FLIP. Currently, we try to
>> support (stateful) AggregateFunctions. I have some concerns about whether
>> or not DataView/MapView/ListView is a good interface because it requires
>> quite some magic from the runners to make it work, such as messing with the
>> TypeInformation and injecting objects at runtime. If the FLIP aims for the
>> minimum of ScalarFunctions and the whole execution harness, that should be
>> easier to agree on.
>> 
>> Another point is the naming of the new methods. I think Timo hinted at the
>> fact that we have to consider catalog support for functions. There is
>> ongoing work about differentiating between temporary objects and objects
>> that are stored in a catalog (FLIP-64 [1]). With this in mind, the method
>> for registering functions should be called register_temporary_function()
>> and so on. Unless we want to already think about mixing Python and Java
>> functions in the catalog, which is outside the scope of this FLIP, I think.
>> 
>> Best,
>> Aljoscha
>> 
>> [1]
>> https://cwiki.apache.org/confluence/display/FLINK/FLIP-64%3A+Support+for+Temporary+Objects+in+Table+module
>> 
>> 
>>> On 5. Sep 2019, at 05:01, jincheng sun  wrote:
>>> 
>>> Hi Aljoscha,
>>> 
>>> That's a good points, so far, most of the code will live in flink-python
>>> module, and the rules and relNodes will be put into the both blink and
>>> flink planner modules, some of the common interface of required by
>> planners
>>> will be placed in flink-table-common. I think you are right, we should
>> try
>>> to ensure the changes of this feature is minimal.  For more detail we
>> would
>>> follow this principle when review the PRs.
>>> 
>>> Great thanks for your questions and remind!
>>> 
>>> Best,
>>> Jincheng
>>> 
>>> 
>>> Aljoscha Krettek  于2019年9月4日周三 下午8:58写道：
>>> 
 Hi,
 
 Things looks interesting so far!
 
 I had one question: Where will most of the support code for this live?
 Will this add the required code to flink-table-common or the different
 runners? Can we implement this in such a way that only a minimal amount
>> of
 support code is required in the parts of the Table API (and Table API
 runners) that  are not python specific?
 
 Best,
 Aljoscha
 
> On 4. Sep 2019, at 14:14, Timo Walther  wrote:
> 
> Hi Jincheng,
> 
> 2. Serializability of functions: "#2 is very convenient for users"
>> means
 only until they have the first backwards-compatibility issue, after that
 they will find it not so convinient anymore and will ask why the
>> framework
 allowed storing such objects in a persistent storage. I don't want to be
 picky about it, but wanted to raise awareness that sometimes it is ok to
 limit use cases to guide users for devloping backwards-compatible
>> programs.
> 
> Thanks for the explanation fo the remaining items. It sounds reasonable
 to me. Regarding the example with `getKind()`, I actually meant
 `org.apache.flink.table.functions.ScalarFunction#getKind` we don't allow
 users to 

Re: [DISCUSS] Flink Python User-Defined Function for Table API

[jincheng sun]

Hi Aljoscha,

Thanks for your comments!

Regarding to the FLIP scope, it seems that we have agreed on the design of
the stateless function support.
What do you think about starting the development of the stateless function
support firstly and continue the discussion of stateful function support?
Or you think we should split the current FLIP into two FLIPs and discuss
the stateful function support in another thread?

Currently, the Python DataView/MapView/ListView interfaces design follow
the Java/Scala naming conversions.
Of couse, We can continue to discuss whether there are better solutions,
i.e. using annotations.

Regarding to the magic logic to support DataView/MapView/ListView, it will
be done by the framework and is transparent for users.
Per my understanding, the magic logic is unavoidable no matter what the
interfaces will be.

Regarding to the catalog support of python function:1) If it's stored in
memory as temporary object, just as you said, users can call
TableEnvironment.register_function(will change to
register_temporary_function in FLIP-64)
2) If it's persisted in external storage, users can call
Catalog.create_function. There will be no API change per my understanding.

What do you think?
Best,Jincheng

Aljoscha Krettek  于2019年9月5日周四 下午5:32写道：

> Hi,
>
> Another thing to consider is the Scope of the FLIP. Currently, we try to
> support (stateful) AggregateFunctions. I have some concerns about whether
> or not DataView/MapView/ListView is a good interface because it requires
> quite some magic from the runners to make it work, such as messing with the
> TypeInformation and injecting objects at runtime. If the FLIP aims for the
> minimum of ScalarFunctions and the whole execution harness, that should be
> easier to agree on.
>
> Another point is the naming of the new methods. I think Timo hinted at the
> fact that we have to consider catalog support for functions. There is
> ongoing work about differentiating between temporary objects and objects
> that are stored in a catalog (FLIP-64 [1]). With this in mind, the method
> for registering functions should be called register_temporary_function()
> and so on. Unless we want to already think about mixing Python and Java
> functions in the catalog, which is outside the scope of this FLIP, I think.
>
> Best,
> Aljoscha
>
> [1]
> https://cwiki.apache.org/confluence/display/FLINK/FLIP-64%3A+Support+for+Temporary+Objects+in+Table+module
>
>
> > On 5. Sep 2019, at 05:01, jincheng sun  wrote:
> >
> > Hi Aljoscha,
> >
> > That's a good points, so far, most of the code will live in flink-python
> > module, and the rules and relNodes will be put into the both blink and
> > flink planner modules, some of the common interface of required by
> planners
> > will be placed in flink-table-common. I think you are right, we should
> try
> > to ensure the changes of this feature is minimal.  For more detail we
> would
> > follow this principle when review the PRs.
> >
> > Great thanks for your questions and remind!
> >
> > Best,
> > Jincheng
> >
> >
> > Aljoscha Krettek  于2019年9月4日周三 下午8:58写道：
> >
> >> Hi,
> >>
> >> Things looks interesting so far!
> >>
> >> I had one question: Where will most of the support code for this live?
> >> Will this add the required code to flink-table-common or the different
> >> runners? Can we implement this in such a way that only a minimal amount
> of
> >> support code is required in the parts of the Table API (and Table API
> >> runners) that  are not python specific?
> >>
> >> Best,
> >> Aljoscha
> >>
> >>> On 4. Sep 2019, at 14:14, Timo Walther  wrote:
> >>>
> >>> Hi Jincheng,
> >>>
> >>> 2. Serializability of functions: "#2 is very convenient for users"
> means
> >> only until they have the first backwards-compatibility issue, after that
> >> they will find it not so convinient anymore and will ask why the
> framework
> >> allowed storing such objects in a persistent storage. I don't want to be
> >> picky about it, but wanted to raise awareness that sometimes it is ok to
> >> limit use cases to guide users for devloping backwards-compatible
> programs.
> >>>
> >>> Thanks for the explanation fo the remaining items. It sounds reasonable
> >> to me. Regarding the example with `getKind()`, I actually meant
> >> `org.apache.flink.table.functions.ScalarFunction#getKind` we don't allow
> >> users to override this property. And I think we should do something
> similar
> >> for the getLanguage property.
> >>>
> >>> Thanks,
> >>> Timo
> >>>
> >>> On 03.09.19 15:01, jincheng sun wrote:
>  Hi Timo,
> 
>  Thanks for the quick reply ! :)
>  I have added more example for #3 and #5 to the FLIP. That are great
>  suggestions !
> 
>  Regarding 2:
> 
>  There are two kind Serialization for CloudPickle(Which is different
> from
>  Java):
>  1) For class and function which can be imported, CloudPickle only
>  serialize the full path of the class and function (just like java
> class
>  name).
> 

Re: [DISCUSS] Flink Python User-Defined Function for Table API

[Aljoscha Krettek]

Hi,

Another thing to consider is the Scope of the FLIP. Currently, we try to 
support (stateful) AggregateFunctions. I have some concerns about whether or 
not DataView/MapView/ListView is a good interface because it requires quite 
some magic from the runners to make it work, such as messing with the 
TypeInformation and injecting objects at runtime. If the FLIP aims for the 
minimum of ScalarFunctions and the whole execution harness, that should be 
easier to agree on.

Another point is the naming of the new methods. I think Timo hinted at the fact 
that we have to consider catalog support for functions. There is ongoing work 
about differentiating between temporary objects and objects that are stored in 
a catalog (FLIP-64 [1]). With this in mind, the method for registering 
functions should be called register_temporary_function() and so on. Unless we 
want to already think about mixing Python and Java functions in the catalog, 
which is outside the scope of this FLIP, I think.

Best,
Aljoscha

[1] 
https://cwiki.apache.org/confluence/display/FLINK/FLIP-64%3A+Support+for+Temporary+Objects+in+Table+module


> On 5. Sep 2019, at 05:01, jincheng sun  wrote:
> 
> Hi Aljoscha,
> 
> That's a good points, so far, most of the code will live in flink-python
> module, and the rules and relNodes will be put into the both blink and
> flink planner modules, some of the common interface of required by planners
> will be placed in flink-table-common. I think you are right, we should try
> to ensure the changes of this feature is minimal.  For more detail we would
> follow this principle when review the PRs.
> 
> Great thanks for your questions and remind!
> 
> Best,
> Jincheng
> 
> 
> Aljoscha Krettek  于2019年9月4日周三 下午8:58写道：
> 
>> Hi,
>> 
>> Things looks interesting so far!
>> 
>> I had one question: Where will most of the support code for this live?
>> Will this add the required code to flink-table-common or the different
>> runners? Can we implement this in such a way that only a minimal amount of
>> support code is required in the parts of the Table API (and Table API
>> runners) that  are not python specific?
>> 
>> Best,
>> Aljoscha
>> 
>>> On 4. Sep 2019, at 14:14, Timo Walther  wrote:
>>> 
>>> Hi Jincheng,
>>> 
>>> 2. Serializability of functions: "#2 is very convenient for users" means
>> only until they have the first backwards-compatibility issue, after that
>> they will find it not so convinient anymore and will ask why the framework
>> allowed storing such objects in a persistent storage. I don't want to be
>> picky about it, but wanted to raise awareness that sometimes it is ok to
>> limit use cases to guide users for devloping backwards-compatible programs.
>>> 
>>> Thanks for the explanation fo the remaining items. It sounds reasonable
>> to me. Regarding the example with `getKind()`, I actually meant
>> `org.apache.flink.table.functions.ScalarFunction#getKind` we don't allow
>> users to override this property. And I think we should do something similar
>> for the getLanguage property.
>>> 
>>> Thanks,
>>> Timo
>>> 
>>> On 03.09.19 15:01, jincheng sun wrote:
 Hi Timo,
 
 Thanks for the quick reply ! :)
 I have added more example for #3 and #5 to the FLIP. That are great
 suggestions !
 
 Regarding 2:
 
 There are two kind Serialization for CloudPickle(Which is different from
 Java):
 1) For class and function which can be imported, CloudPickle only
 serialize the full path of the class and function (just like java class
 name).
 2) For the class and function which can not be imported, CloudPickle
>> will
 serialize the full content of the class and function.
 For #2, It means that we can not just store the full path of the class
>> and
 function.
 
 The above serialization is recursive.
 
 However, there is indeed an problem of backwards compatibility when the
 module path of the parent class changed. But I think this is an rare
>> case
 and acceptable. i.e., For Flink framework we never change the user
 interface module path if we want to keep backwards compatibility. For
>> user
 code, if they change the interface of UDF's parent, they should
>> re-register
 their functions.
 
 If we do not want support #2, we can store the full path of class and
 function, in that case we have no backwards compatibility problem. But I
 think the #2 is very convenient for users.
 
 What do you think?
 
 Regarding 4:
 As I mentioned earlier, there may be built-in Python functions and I
>> think
 language is a "function" concept. Function and Language are orthogonal
 concepts.
 We may have R, GO and other language functions in the future, not only
 user-defined, but also built-in functions.
 
 You are right that users will not set this method and for Python
>> functions,
 it will be set in the code-generated Java function by the framework.
>> So, I
 

Re: [DISCUSS] Flink Python User-Defined Function for Table API

[jincheng sun]

Hi Aljoscha,

That's a good points, so far, most of the code will live in flink-python
module, and the rules and relNodes will be put into the both blink and
flink planner modules, some of the common interface of required by planners
will be placed in flink-table-common. I think you are right, we should try
to ensure the changes of this feature is minimal.  For more detail we would
follow this principle when review the PRs.

Great thanks for your questions and remind!

Best,
Jincheng


Aljoscha Krettek  于2019年9月4日周三 下午8:58写道：

> Hi,
>
> Things looks interesting so far!
>
> I had one question: Where will most of the support code for this live?
> Will this add the required code to flink-table-common or the different
> runners? Can we implement this in such a way that only a minimal amount of
> support code is required in the parts of the Table API (and Table API
> runners) that  are not python specific?
>
> Best,
> Aljoscha
>
> > On 4. Sep 2019, at 14:14, Timo Walther  wrote:
> >
> > Hi Jincheng,
> >
> > 2. Serializability of functions: "#2 is very convenient for users" means
> only until they have the first backwards-compatibility issue, after that
> they will find it not so convinient anymore and will ask why the framework
> allowed storing such objects in a persistent storage. I don't want to be
> picky about it, but wanted to raise awareness that sometimes it is ok to
> limit use cases to guide users for devloping backwards-compatible programs.
> >
> > Thanks for the explanation fo the remaining items. It sounds reasonable
> to me. Regarding the example with `getKind()`, I actually meant
> `org.apache.flink.table.functions.ScalarFunction#getKind` we don't allow
> users to override this property. And I think we should do something similar
> for the getLanguage property.
> >
> > Thanks,
> > Timo
> >
> > On 03.09.19 15:01, jincheng sun wrote:
> >> Hi Timo,
> >>
> >> Thanks for the quick reply ! :)
> >> I have added more example for #3 and #5 to the FLIP. That are great
> >> suggestions !
> >>
> >> Regarding 2:
> >>
> >> There are two kind Serialization for CloudPickle(Which is different from
> >> Java):
> >>  1) For class and function which can be imported, CloudPickle only
> >> serialize the full path of the class and function (just like java class
> >> name).
> >>  2) For the class and function which can not be imported, CloudPickle
> will
> >> serialize the full content of the class and function.
> >> For #2, It means that we can not just store the full path of the class
> and
> >> function.
> >>
> >> The above serialization is recursive.
> >>
> >> However, there is indeed an problem of backwards compatibility when the
> >> module path of the parent class changed. But I think this is an rare
> case
> >> and acceptable. i.e., For Flink framework we never change the user
> >> interface module path if we want to keep backwards compatibility. For
> user
> >> code, if they change the interface of UDF's parent, they should
> re-register
> >> their functions.
> >>
> >> If we do not want support #2, we can store the full path of class and
> >> function, in that case we have no backwards compatibility problem. But I
> >> think the #2 is very convenient for users.
> >>
> >> What do you think?
> >>
> >> Regarding 4:
> >> As I mentioned earlier, there may be built-in Python functions and I
> think
> >> language is a "function" concept. Function and Language are orthogonal
> >> concepts.
> >> We may have R, GO and other language functions in the future, not only
> >> user-defined, but also built-in functions.
> >>
> >> You are right that users will not set this method and for Python
> functions,
> >> it will be set in the code-generated Java function by the framework.
> So, I
> >> think we should declare the getLanguage() in FunctionDefinition for now.
> >> (I'm not pretty sure what do you mean by saying that getKind() is final
> in
> >> UserDefinedFunction?)
> >>
> >> Best,
> >> Jincheng
> >>
> >> Timo Walther  于2019年9月3日周二 下午6:01写道：
> >>
> >>> Hi Jincheng,
> >>>
> >>> thanks for your response.
> >>>
> >>> 2. Serializability of functions: Using some arbitrary serialization
> >>> format for shipping a function to worker sounds fine to me. But once we
> >>> store functions a the catalog we need to think about backwards
> >>> compatibility and evolution of interfaces etc. I'm not sure if
> >>> CloudPickle is the right long-term storage format for this. If we don't
> >>> think about this in advance, we are basically violating our code
> quality
> >>> guide [1] of never use Java Serialization but in the Python-way. We are
> >>> using the RPC serialization for persistence.
> >>>
> >>> 3. TableEnvironment: Can you add some example to the FLIP? Because API
> >>> code like the following is not covered there:
> >>>
> >>> self.t_env.register_function("add_one", udf(lambda i: i + 1,
> >>> DataTypes.BIGINT(),
> >>>  DataTypes.BIGINT()))
> >>> 

Re: [DISCUSS] Flink Python User-Defined Function for Table API

[jincheng sun]

Hi Timo,

Yes, I think about convenient is a trade-off, for now think convenient
compare with always do right thing I prefer add some limitation ensure user
never encounter issues. So, #2 we are on the same page now.

Best,
Jincheng

Aljoscha Krettek  于2019年9月4日周三 下午8:58写道：

> Hi,
>
> Things looks interesting so far!
>
> I had one question: Where will most of the support code for this live?
> Will this add the required code to flink-table-common or the different
> runners? Can we implement this in such a way that only a minimal amount of
> support code is required in the parts of the Table API (and Table API
> runners) that  are not python specific?
>
> Best,
> Aljoscha
>
> > On 4. Sep 2019, at 14:14, Timo Walther  wrote:
> >
> > Hi Jincheng,
> >
> > 2. Serializability of functions: "#2 is very convenient for users" means
> only until they have the first backwards-compatibility issue, after that
> they will find it not so convinient anymore and will ask why the framework
> allowed storing such objects in a persistent storage. I don't want to be
> picky about it, but wanted to raise awareness that sometimes it is ok to
> limit use cases to guide users for devloping backwards-compatible programs.
> >
> > Thanks for the explanation fo the remaining items. It sounds reasonable
> to me. Regarding the example with `getKind()`, I actually meant
> `org.apache.flink.table.functions.ScalarFunction#getKind` we don't allow
> users to override this property. And I think we should do something similar
> for the getLanguage property.
> >
> > Thanks,
> > Timo
> >
> > On 03.09.19 15:01, jincheng sun wrote:
> >> Hi Timo,
> >>
> >> Thanks for the quick reply ! :)
> >> I have added more example for #3 and #5 to the FLIP. That are great
> >> suggestions !
> >>
> >> Regarding 2:
> >>
> >> There are two kind Serialization for CloudPickle(Which is different from
> >> Java):
> >>  1) For class and function which can be imported, CloudPickle only
> >> serialize the full path of the class and function (just like java class
> >> name).
> >>  2) For the class and function which can not be imported, CloudPickle
> will
> >> serialize the full content of the class and function.
> >> For #2, It means that we can not just store the full path of the class
> and
> >> function.
> >>
> >> The above serialization is recursive.
> >>
> >> However, there is indeed an problem of backwards compatibility when the
> >> module path of the parent class changed. But I think this is an rare
> case
> >> and acceptable. i.e., For Flink framework we never change the user
> >> interface module path if we want to keep backwards compatibility. For
> user
> >> code, if they change the interface of UDF's parent, they should
> re-register
> >> their functions.
> >>
> >> If we do not want support #2, we can store the full path of class and
> >> function, in that case we have no backwards compatibility problem. But I
> >> think the #2 is very convenient for users.
> >>
> >> What do you think?
> >>
> >> Regarding 4:
> >> As I mentioned earlier, there may be built-in Python functions and I
> think
> >> language is a "function" concept. Function and Language are orthogonal
> >> concepts.
> >> We may have R, GO and other language functions in the future, not only
> >> user-defined, but also built-in functions.
> >>
> >> You are right that users will not set this method and for Python
> functions,
> >> it will be set in the code-generated Java function by the framework.
> So, I
> >> think we should declare the getLanguage() in FunctionDefinition for now.
> >> (I'm not pretty sure what do you mean by saying that getKind() is final
> in
> >> UserDefinedFunction?)
> >>
> >> Best,
> >> Jincheng
> >>
> >> Timo Walther  于2019年9月3日周二 下午6:01写道：
> >>
> >>> Hi Jincheng,
> >>>
> >>> thanks for your response.
> >>>
> >>> 2. Serializability of functions: Using some arbitrary serialization
> >>> format for shipping a function to worker sounds fine to me. But once we
> >>> store functions a the catalog we need to think about backwards
> >>> compatibility and evolution of interfaces etc. I'm not sure if
> >>> CloudPickle is the right long-term storage format for this. If we don't
> >>> think about this in advance, we are basically violating our code
> quality
> >>> guide [1] of never use Java Serialization but in the Python-way. We are
> >>> using the RPC serialization for persistence.
> >>>
> >>> 3. TableEnvironment: Can you add some example to the FLIP? Because API
> >>> code like the following is not covered there:
> >>>
> >>> self.t_env.register_function("add_one", udf(lambda i: i + 1,
> >>> DataTypes.BIGINT(),
> >>>  DataTypes.BIGINT()))
> >>> self.t_env.register_function("subtract_one", udf(SubtractOne(),
> >>> DataTypes.BIGINT(),
> >>> DataTypes.BIGINT()))
> >>> self.t_env.register_function("add", add)
> >>>
> >>> 4. FunctionDefinition: Your response still doesn't answer my question
> >>> entirely. Why do we need 

Re: [DISCUSS] Flink Python User-Defined Function for Table API

[Aljoscha Krettek]

Hi,

Things looks interesting so far!

I had one question: Where will most of the support code for this live? Will 
this add the required code to flink-table-common or the different runners? Can 
we implement this in such a way that only a minimal amount of support code is 
required in the parts of the Table API (and Table API runners) that  are not 
python specific?

Best,
Aljoscha

> On 4. Sep 2019, at 14:14, Timo Walther  wrote:
> 
> Hi Jincheng,
> 
> 2. Serializability of functions: "#2 is very convenient for users" means only 
> until they have the first backwards-compatibility issue, after that they will 
> find it not so convinient anymore and will ask why the framework allowed 
> storing such objects in a persistent storage. I don't want to be picky about 
> it, but wanted to raise awareness that sometimes it is ok to limit use cases 
> to guide users for devloping backwards-compatible programs.
> 
> Thanks for the explanation fo the remaining items. It sounds reasonable to 
> me. Regarding the example with `getKind()`, I actually meant 
> `org.apache.flink.table.functions.ScalarFunction#getKind` we don't allow 
> users to override this property. And I think we should do something similar 
> for the getLanguage property.
> 
> Thanks,
> Timo
> 
> On 03.09.19 15:01, jincheng sun wrote:
>> Hi Timo,
>> 
>> Thanks for the quick reply ! :)
>> I have added more example for #3 and #5 to the FLIP. That are great
>> suggestions !
>> 
>> Regarding 2:
>> 
>> There are two kind Serialization for CloudPickle(Which is different from
>> Java):
>>  1) For class and function which can be imported, CloudPickle only
>> serialize the full path of the class and function (just like java class
>> name).
>>  2) For the class and function which can not be imported, CloudPickle will
>> serialize the full content of the class and function.
>> For #2, It means that we can not just store the full path of the class and
>> function.
>> 
>> The above serialization is recursive.
>> 
>> However, there is indeed an problem of backwards compatibility when the
>> module path of the parent class changed. But I think this is an rare case
>> and acceptable. i.e., For Flink framework we never change the user
>> interface module path if we want to keep backwards compatibility. For user
>> code, if they change the interface of UDF's parent, they should re-register
>> their functions.
>> 
>> If we do not want support #2, we can store the full path of class and
>> function, in that case we have no backwards compatibility problem. But I
>> think the #2 is very convenient for users.
>> 
>> What do you think?
>> 
>> Regarding 4:
>> As I mentioned earlier, there may be built-in Python functions and I think
>> language is a "function" concept. Function and Language are orthogonal
>> concepts.
>> We may have R, GO and other language functions in the future, not only
>> user-defined, but also built-in functions.
>> 
>> You are right that users will not set this method and for Python functions,
>> it will be set in the code-generated Java function by the framework. So, I
>> think we should declare the getLanguage() in FunctionDefinition for now.
>> (I'm not pretty sure what do you mean by saying that getKind() is final in
>> UserDefinedFunction?)
>> 
>> Best,
>> Jincheng
>> 
>> Timo Walther  于2019年9月3日周二 下午6:01写道：
>> 
>>> Hi Jincheng,
>>> 
>>> thanks for your response.
>>> 
>>> 2. Serializability of functions: Using some arbitrary serialization
>>> format for shipping a function to worker sounds fine to me. But once we
>>> store functions a the catalog we need to think about backwards
>>> compatibility and evolution of interfaces etc. I'm not sure if
>>> CloudPickle is the right long-term storage format for this. If we don't
>>> think about this in advance, we are basically violating our code quality
>>> guide [1] of never use Java Serialization but in the Python-way. We are
>>> using the RPC serialization for persistence.
>>> 
>>> 3. TableEnvironment: Can you add some example to the FLIP? Because API
>>> code like the following is not covered there:
>>> 
>>> self.t_env.register_function("add_one", udf(lambda i: i + 1,
>>> DataTypes.BIGINT(),
>>>  DataTypes.BIGINT()))
>>> self.t_env.register_function("subtract_one", udf(SubtractOne(),
>>> DataTypes.BIGINT(),
>>> DataTypes.BIGINT()))
>>> self.t_env.register_function("add", add)
>>> 
>>> 4. FunctionDefinition: Your response still doesn't answer my question
>>> entirely. Why do we need FunctionDefinition.getLanguage() if this is a
>>> "user-defined function" concept and not a "function" concept. In any
>>> case, all users should not be able to set this method. So it must be
>>> final in UserDefinedFunction similar to getKind().
>>> 
>>> 5. Function characteristics: If UserDefinedFunction is defined in
>>> Python, why is it not used in your example in FLIP-58. You could you
>>> extend the example to show how to specify these attributes in the FLIP?
>>> 
>>> 

Re: [DISCUSS] Flink Python User-Defined Function for Table API

[Timo Walther]

Hi Jincheng,

2. Serializability of functions: "#2 is very convenient for users" means 
only until they have the first backwards-compatibility issue, after that 
they will find it not so convinient anymore and will ask why the 
framework allowed storing such objects in a persistent storage. I don't 
want to be picky about it, but wanted to raise awareness that sometimes 
it is ok to limit use cases to guide users for devloping 
backwards-compatible programs.


Thanks for the explanation fo the remaining items. It sounds reasonable 
to me. Regarding the example with `getKind()`, I actually meant 
`org.apache.flink.table.functions.ScalarFunction#getKind` we don't allow 
users to override this property. And I think we should do something 
similar for the getLanguage property.


Thanks,
Timo

On 03.09.19 15:01, jincheng sun wrote:

Hi Timo,

Thanks for the quick reply ! :)
I have added more example for #3 and #5 to the FLIP. That are great
suggestions !

Regarding 2:

There are two kind Serialization for CloudPickle(Which is different from
Java):
  1) For class and function which can be imported, CloudPickle only
serialize the full path of the class and function (just like java class
name).
  2) For the class and function which can not be imported, CloudPickle will
serialize the full content of the class and function.
For #2, It means that we can not just store the full path of the class and
function.

The above serialization is recursive.

However, there is indeed an problem of backwards compatibility when the
module path of the parent class changed. But I think this is an rare case
and acceptable. i.e., For Flink framework we never change the user
interface module path if we want to keep backwards compatibility. For user
code, if they change the interface of UDF's parent, they should re-register
their functions.

If we do not want support #2, we can store the full path of class and
function, in that case we have no backwards compatibility problem. But I
think the #2 is very convenient for users.

What do you think?

Regarding 4:
As I mentioned earlier, there may be built-in Python functions and I think
language is a "function" concept. Function and Language are orthogonal
concepts.
We may have R, GO and other language functions in the future, not only
user-defined, but also built-in functions.

You are right that users will not set this method and for Python functions,
it will be set in the code-generated Java function by the framework. So, I
think we should declare the getLanguage() in FunctionDefinition for now.
(I'm not pretty sure what do you mean by saying that getKind() is final in
UserDefinedFunction?)

Best,
Jincheng

Timo Walther  于2019年9月3日周二 下午6:01写道：


Hi Jincheng,

thanks for your response.

2. Serializability of functions: Using some arbitrary serialization
format for shipping a function to worker sounds fine to me. But once we
store functions a the catalog we need to think about backwards
compatibility and evolution of interfaces etc. I'm not sure if
CloudPickle is the right long-term storage format for this. If we don't
think about this in advance, we are basically violating our code quality
guide [1] of never use Java Serialization but in the Python-way. We are
using the RPC serialization for persistence.

3. TableEnvironment: Can you add some example to the FLIP? Because API
code like the following is not covered there:

self.t_env.register_function("add_one", udf(lambda i: i + 1,
DataTypes.BIGINT(),
  DataTypes.BIGINT()))
self.t_env.register_function("subtract_one", udf(SubtractOne(),
DataTypes.BIGINT(),
DataTypes.BIGINT()))
self.t_env.register_function("add", add)

4. FunctionDefinition: Your response still doesn't answer my question
entirely. Why do we need FunctionDefinition.getLanguage() if this is a
"user-defined function" concept and not a "function" concept. In any
case, all users should not be able to set this method. So it must be
final in UserDefinedFunction similar to getKind().

5. Function characteristics: If UserDefinedFunction is defined in
Python, why is it not used in your example in FLIP-58. You could you
extend the example to show how to specify these attributes in the FLIP?

Regards,
Timo

[1] https://flink.apache.org/contributing/code-style-and-quality-java.html

On 02.09.19 15:35, jincheng sun wrote:

Hi Timo,

Great thanks for your feedback. I would like to share my thoughts with

you

inline. :)

Best,
Jincheng

Timo Walther  于2019年9月2日周一 下午5:04写道：


Hi all,

the FLIP looks awesome. However, I would like to discuss the changes to
the user-facing parts again. Some feedback:

1. DataViews: With the current non-annotation design for DataViews, we
cannot perform eager state declaration, right? At which point during
execution do we know which state is required by the function? We need to
instantiate the function first, right?


We will analysis the Python AggregateFunction and extract the DataViews

used in the Python 

Re: [DISCUSS] Flink Python User-Defined Function for Table API

[jincheng sun]

Hi Timo,

Thanks for the quick reply ! :)
I have added more example for #3 and #5 to the FLIP. That are great
suggestions !

Regarding 2:

There are two kind Serialization for CloudPickle(Which is different from
Java):
 1) For class and function which can be imported, CloudPickle only
serialize the full path of the class and function (just like java class
name).
 2) For the class and function which can not be imported, CloudPickle will
serialize the full content of the class and function.
For #2, It means that we can not just store the full path of the class and
function.

The above serialization is recursive.

However, there is indeed an problem of backwards compatibility when the
module path of the parent class changed. But I think this is an rare case
and acceptable. i.e., For Flink framework we never change the user
interface module path if we want to keep backwards compatibility. For user
code, if they change the interface of UDF's parent, they should re-register
their functions.

If we do not want support #2, we can store the full path of class and
function, in that case we have no backwards compatibility problem. But I
think the #2 is very convenient for users.

What do you think?

Regarding 4:
As I mentioned earlier, there may be built-in Python functions and I think
language is a "function" concept. Function and Language are orthogonal
concepts.
We may have R, GO and other language functions in the future, not only
user-defined, but also built-in functions.

You are right that users will not set this method and for Python functions,
it will be set in the code-generated Java function by the framework. So, I
think we should declare the getLanguage() in FunctionDefinition for now.
(I'm not pretty sure what do you mean by saying that getKind() is final in
UserDefinedFunction?)

Best,
Jincheng

Timo Walther  于2019年9月3日周二 下午6:01写道：

> Hi Jincheng,
>
> thanks for your response.
>
> 2. Serializability of functions: Using some arbitrary serialization
> format for shipping a function to worker sounds fine to me. But once we
> store functions a the catalog we need to think about backwards
> compatibility and evolution of interfaces etc. I'm not sure if
> CloudPickle is the right long-term storage format for this. If we don't
> think about this in advance, we are basically violating our code quality
> guide [1] of never use Java Serialization but in the Python-way. We are
> using the RPC serialization for persistence.
>
> 3. TableEnvironment: Can you add some example to the FLIP? Because API
> code like the following is not covered there:
>
> self.t_env.register_function("add_one", udf(lambda i: i + 1,
> DataTypes.BIGINT(),
>  DataTypes.BIGINT()))
> self.t_env.register_function("subtract_one", udf(SubtractOne(),
> DataTypes.BIGINT(),
> DataTypes.BIGINT()))
> self.t_env.register_function("add", add)
>
> 4. FunctionDefinition: Your response still doesn't answer my question
> entirely. Why do we need FunctionDefinition.getLanguage() if this is a
> "user-defined function" concept and not a "function" concept. In any
> case, all users should not be able to set this method. So it must be
> final in UserDefinedFunction similar to getKind().
>
> 5. Function characteristics: If UserDefinedFunction is defined in
> Python, why is it not used in your example in FLIP-58. You could you
> extend the example to show how to specify these attributes in the FLIP?
>
> Regards,
> Timo
>
> [1] https://flink.apache.org/contributing/code-style-and-quality-java.html
>
> On 02.09.19 15:35, jincheng sun wrote:
> > Hi Timo,
> >
> > Great thanks for your feedback. I would like to share my thoughts with
> you
> > inline. :)
> >
> > Best,
> > Jincheng
> >
> > Timo Walther  于2019年9月2日周一 下午5:04写道：
> >
> >> Hi all,
> >>
> >> the FLIP looks awesome. However, I would like to discuss the changes to
> >> the user-facing parts again. Some feedback:
> >>
> >> 1. DataViews: With the current non-annotation design for DataViews, we
> >> cannot perform eager state declaration, right? At which point during
> >> execution do we know which state is required by the function? We need to
> >> instantiate the function first, right?
> >>
> >>> We will analysis the Python AggregateFunction and extract the DataViews
> > used in the Python AggregateFunction. This can be done
> > by instantiate a Python AggregateFunction, creating an accumulator by
> > calling method create_accumulator and then analysis the created
> > accumulator. This is actually similar to the way that Java
> > AggregateFunction processing codegen logic. The extracted DataViews can
> > then be used to construct the StateDescriptors in the operator, i.e., we
> > should have hold the state spec and the state descriptor id in Java
> > operator and Python worker can access the state by specifying the
> > corresponding state descriptor id.
> >
> >
> >
> >> 2. Serializability of functions: How do we ensure serializability of
> >> functions for catalog 

Re: [DISCUSS] Flink Python User-Defined Function for Table API

[Timo Walther]

Hi Jincheng,

thanks for your response.

2. Serializability of functions: Using some arbitrary serialization 
format for shipping a function to worker sounds fine to me. But once we 
store functions a the catalog we need to think about backwards 
compatibility and evolution of interfaces etc. I'm not sure if 
CloudPickle is the right long-term storage format for this. If we don't 
think about this in advance, we are basically violating our code quality 
guide [1] of never use Java Serialization but in the Python-way. We are 
using the RPC serialization for persistence.


3. TableEnvironment: Can you add some example to the FLIP? Because API 
code like the following is not covered there:


self.t_env.register_function("add_one", udf(lambda i: i + 1, 
DataTypes.BIGINT(),

    DataTypes.BIGINT()))
self.t_env.register_function("subtract_one", udf(SubtractOne(), 
DataTypes.BIGINT(),

DataTypes.BIGINT()))
self.t_env.register_function("add", add)

4. FunctionDefinition: Your response still doesn't answer my question 
entirely. Why do we need FunctionDefinition.getLanguage() if this is a 
"user-defined function" concept and not a "function" concept. In any 
case, all users should not be able to set this method. So it must be 
final in UserDefinedFunction similar to getKind().


5. Function characteristics: If UserDefinedFunction is defined in 
Python, why is it not used in your example in FLIP-58. You could you 
extend the example to show how to specify these attributes in the FLIP?


Regards,
Timo

[1] https://flink.apache.org/contributing/code-style-and-quality-java.html

On 02.09.19 15:35, jincheng sun wrote:

Hi Timo,

Great thanks for your feedback. I would like to share my thoughts with you
inline. :)

Best,
Jincheng

Timo Walther  于2019年9月2日周一 下午5:04写道：


Hi all,

the FLIP looks awesome. However, I would like to discuss the changes to
the user-facing parts again. Some feedback:

1. DataViews: With the current non-annotation design for DataViews, we
cannot perform eager state declaration, right? At which point during
execution do we know which state is required by the function? We need to
instantiate the function first, right?


We will analysis the Python AggregateFunction and extract the DataViews

used in the Python AggregateFunction. This can be done
by instantiate a Python AggregateFunction, creating an accumulator by
calling method create_accumulator and then analysis the created
accumulator. This is actually similar to the way that Java
AggregateFunction processing codegen logic. The extracted DataViews can
then be used to construct the StateDescriptors in the operator, i.e., we
should have hold the state spec and the state descriptor id in Java
operator and Python worker can access the state by specifying the
corresponding state descriptor id.




2. Serializability of functions: How do we ensure serializability of
functions for catalog persistence? In the Scala/Java API, we would like
to register classes instead of instances soon. This is the only way to
store a function properly in a catalog or we need some
serialization/deserialization logic in the function interfaces to
convert an instance to string properties.


The Python function will be serialized with CloudPickle anyway in the

Python API as we need to transfer it to the Python worker which can then
deserialize it for execution. The serialized Python function can be stored
into catalog.




3. TableEnvironment: What is the signature of `register_function(self,
name, function)`? Does it accept both a class and function? Like `class
Sum` and `def split()`? Could you add some examples for registering both
kinds of functions?


It has been already supported which you mentioned. You can find an

example in the POC code:
https://github.com/dianfu/flink/commit/93f41ba173482226af7513fdec5acba72b274489#diff-34f619b31a7e38604e22a42a441fbe2fR26




4. FunctionDefinition: Function definition is not a user-defined
function definition. It is the highest interface for both user-defined
and built-in functions. I'm not sure if getLanguage() should be part of
this interface or one-level down which would be `UserDefinedFunction`.
Built-in functions will never be implemented in a different language. In
any case, I would vote for removing the UNKNOWN language, because it
does not solve anything. Why should a user declare a function that the
runtime can not handle? I also find the term `JAVA` confusing for Scala
users. How about `FunctionLanguage.JVM` instead?


Actually we may have built-in Python functions in the future. Regarding

to the following expression: py_udf1(a, b) + py_udf2(c), if there is
built-in Python
funciton for '+' operator, then we don't need to mix using Java and Python
UDFs. In this way, we can improve the execution performance.
Regarding to removing FunctionLanguage.UNKNOWN and renaming
FunctionLanguage.Java to FunctionLanguage.JVM, it makes more sense to me.




5. Function characteristics: In the 

Re: [DISCUSS] Flink Python User-Defined Function for Table API

[jincheng sun]

Hi Timo,

Great thanks for your feedback. I would like to share my thoughts with you
inline. :)

Best,
Jincheng

Timo Walther  于2019年9月2日周一 下午5:04写道：

> Hi all,
>
> the FLIP looks awesome. However, I would like to discuss the changes to
> the user-facing parts again. Some feedback:
>
> 1. DataViews: With the current non-annotation design for DataViews, we
> cannot perform eager state declaration, right? At which point during
> execution do we know which state is required by the function? We need to
> instantiate the function first, right?
>

>> We will analysis the Python AggregateFunction and extract the DataViews
used in the Python AggregateFunction. This can be done
by instantiate a Python AggregateFunction, creating an accumulator by
calling method create_accumulator and then analysis the created
accumulator. This is actually similar to the way that Java
AggregateFunction processing codegen logic. The extracted DataViews can
then be used to construct the StateDescriptors in the operator, i.e., we
should have hold the state spec and the state descriptor id in Java
operator and Python worker can access the state by specifying the
corresponding state descriptor id.



> 2. Serializability of functions: How do we ensure serializability of
> functions for catalog persistence? In the Scala/Java API, we would like
> to register classes instead of instances soon. This is the only way to
> store a function properly in a catalog or we need some
> serialization/deserialization logic in the function interfaces to
> convert an instance to string properties.
>

>> The Python function will be serialized with CloudPickle anyway in the
Python API as we need to transfer it to the Python worker which can then
deserialize it for execution. The serialized Python function can be stored
into catalog.



> 3. TableEnvironment: What is the signature of `register_function(self,
> name, function)`? Does it accept both a class and function? Like `class
> Sum` and `def split()`? Could you add some examples for registering both
> kinds of functions?
>

>> It has been already supported which you mentioned. You can find an
example in the POC code:
https://github.com/dianfu/flink/commit/93f41ba173482226af7513fdec5acba72b274489#diff-34f619b31a7e38604e22a42a441fbe2fR26



> 4. FunctionDefinition: Function definition is not a user-defined
> function definition. It is the highest interface for both user-defined
> and built-in functions. I'm not sure if getLanguage() should be part of
> this interface or one-level down which would be `UserDefinedFunction`.
> Built-in functions will never be implemented in a different language. In
> any case, I would vote for removing the UNKNOWN language, because it
> does not solve anything. Why should a user declare a function that the
> runtime can not handle? I also find the term `JAVA` confusing for Scala
> users. How about `FunctionLanguage.JVM` instead?
>

>> Actually we may have built-in Python functions in the future. Regarding
to the following expression: py_udf1(a, b) + py_udf2(c), if there is
built-in Python
funciton for '+' operator, then we don't need to mix using Java and Python
UDFs. In this way, we can improve the execution performance.
Regarding to removing FunctionLanguage.UNKNOWN and renaming
FunctionLanguage.Java to FunctionLanguage.JVM, it makes more sense to me.



> 5. Function characteristics: In the current design, function classes do
> not extend from any upper class. How can users declare characteristics
> that are present in `FunctionDefinition` like determinism, requirements,
> or soon also monotonism.
>

>> Actually we have defined 'UserDefinedFunction' which is the base class
for all user-defined functions.
We can define the deterministic, requirements, etc in this class.
Currently, we have already supported to define the deterministic.



>
> Thanks,
> Timo
>
>
> On 02.09.19 03:38, Shaoxuan Wang wrote:
> > Hi Jincheng, Fudian, and Aljoscha,
> > I am assuming the proposed python UDX can also be applied to Flink SQL.
> > Is this correct? If yes, I would suggest to title the FLIP as "Flink
> Python
> > User-Defined Function" or "Flink Python User-Defined Function for Table".
> >
> > Regards,
> > Shaoxuan
> >
> >
> > On Wed, Aug 28, 2019 at 12:22 PM jincheng sun 
> > wrote:
> >
> >> Thanks for the feedback Bowen!
> >>
> >> Great thanks for create the FLIP and bring up the VOTE Dian!
> >>
> >> Best, Jincheng
> >>
> >> Dian Fu  于2019年8月28日周三 上午11:32写道：
> >>
> >>> Hi all,
> >>>
> >>> I have started a voting thread [1]. Thanks a lot for your help during
> >>> creating the FLIP @Jincheng.
> >>>
> >>>
> >>> Hi Bowen,
> >>>
> >>> Very appreciated for your comments. I have replied you in the design
> doc.
> >>> As it seems that the comments doesn't affect the overall design, I'll
> not
> >>> cancel the vote for now and we can continue the discussion in the
> design
> >>> doc.
> >>>
> >>> [1]
> >>>
> >>
> 

Re: [DISCUSS] Flink Python User-Defined Function for Table API

[jincheng sun]

Hi Shaoxuan,

Thanks for reminding that. I think "Flink Python User-Defined Function for
Table"  make sense to me.

Best,
Jincheng

Timo Walther  于2019年9月2日周一 下午5:04写道：

> Hi all,
>
> the FLIP looks awesome. However, I would like to discuss the changes to
> the user-facing parts again. Some feedback:
>
> 1. DataViews: With the current non-annotation design for DataViews, we
> cannot perform eager state declaration, right? At which point during
> execution do we know which state is required by the function? We need to
> instantiate the function first, right?
>
> 2. Serializability of functions: How do we ensure serializability of
> functions for catalog persistence? In the Scala/Java API, we would like
> to register classes instead of instances soon. This is the only way to
> store a function properly in a catalog or we need some
> serialization/deserialization logic in the function interfaces to
> convert an instance to string properties.
>
> 3. TableEnvironment: What is the signature of `register_function(self,
> name, function)`? Does it accept both a class and function? Like `class
> Sum` and `def split()`? Could you add some examples for registering both
> kinds of functions?
>
> 4. FunctionDefinition: Function definition is not a user-defined
> function definition. It is the highest interface for both user-defined
> and built-in functions. I'm not sure if getLanguage() should be part of
> this interface or one-level down which would be `UserDefinedFunction`.
> Built-in functions will never be implemented in a different language. In
> any case, I would vote for removing the UNKNOWN language, because it
> does not solve anything. Why should a user declare a function that the
> runtime can not handle? I also find the term `JAVA` confusing for Scala
> users. How about `FunctionLanguage.JVM` instead?
>
> 5. Function characteristics: In the current design, function classes do
> not extend from any upper class. How can users declare characteristics
> that are present in `FunctionDefinition` like determinism, requirements,
> or soon also monotonism.
>
> Thanks,
> Timo
>
>
> On 02.09.19 03:38, Shaoxuan Wang wrote:
> > Hi Jincheng, Fudian, and Aljoscha,
> > I am assuming the proposed python UDX can also be applied to Flink SQL.
> > Is this correct? If yes, I would suggest to title the FLIP as "Flink
> Python
> > User-Defined Function" or "Flink Python User-Defined Function for Table".
> >
> > Regards,
> > Shaoxuan
> >
> >
> > On Wed, Aug 28, 2019 at 12:22 PM jincheng sun 
> > wrote:
> >
> >> Thanks for the feedback Bowen!
> >>
> >> Great thanks for create the FLIP and bring up the VOTE Dian!
> >>
> >> Best, Jincheng
> >>
> >> Dian Fu  于2019年8月28日周三 上午11:32写道：
> >>
> >>> Hi all,
> >>>
> >>> I have started a voting thread [1]. Thanks a lot for your help during
> >>> creating the FLIP @Jincheng.
> >>>
> >>>
> >>> Hi Bowen,
> >>>
> >>> Very appreciated for your comments. I have replied you in the design
> doc.
> >>> As it seems that the comments doesn't affect the overall design, I'll
> not
> >>> cancel the vote for now and we can continue the discussion in the
> design
> >>> doc.
> >>>
> >>> [1]
> >>>
> >>
> http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/VOTE-FLIP-58-Flink-Python-User-Defined-Function-for-Table-API-td32295.html
> >>> <
> >>>
> >>
> http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/VOTE-FLIP-58-Flink-Python-User-Defined-Function-for-Table-API-td32295.html
> >>> Regards,
> >>> Dian
> >>>
>  在 2019年8月28日，上午11:05，Bowen Li  写道：
> 
>  Hi Jincheng and Dian,
> 
>  Sorry for being late to the party. I took a glance at the proposal,
> >> LGTM
> >>> in
>  general, and I left only a couple comments.
> 
>  Thanks,
>  Bowen
> 
> 
>  On Mon, Aug 26, 2019 at 8:05 PM Dian Fu 
> wrote:
> 
> > Hi Jincheng,
> >
> > Thanks! It works.
> >
> > Thanks,
> > Dian
> >
> >> 在 2019年8月27日，上午10:55，jincheng sun  写道：
> >>
> >> Hi Dian, can you check if you have edit access? :)
> >>
> >>
> >> Dian Fu  于2019年8月26日周一 上午10:52写道：
> >>
> >>> Hi Jincheng,
> >>>
> >>> Appreciated for the kind tips and offering of help. Definitely need
> >>> it!
> >>> Could you grant me write permission for confluence? My Id: Dian Fu
> >>>
> >>> Thanks,
> >>> Dian
> >>>
>  在 2019年8月26日，上午9:53，jincheng sun  写道：
> 
>  Thanks for your feedback Hequn & Dian.
> 
>  Dian, I am glad to see that you want help to create the FLIP!
>  Everyone will have first time, and I am very willing to help you
> > complete
>  your first FLIP creation. Here some tips:
> 
>  - First I'll give your account write permission for confluence.
>  - Before create the FLIP, please have look at the FLIP Template
> >> [1],
> >>> (It's
>  better to know more about FLIP by reading [2])
>  - Create Flink Python UDFs related 

Re: [DISCUSS] Flink Python User-Defined Function for Table API

[Timo Walther]

Hi all,

the FLIP looks awesome. However, I would like to discuss the changes to 
the user-facing parts again. Some feedback:


1. DataViews: With the current non-annotation design for DataViews, we 
cannot perform eager state declaration, right? At which point during 
execution do we know which state is required by the function? We need to 
instantiate the function first, right?


2. Serializability of functions: How do we ensure serializability of 
functions for catalog persistence? In the Scala/Java API, we would like 
to register classes instead of instances soon. This is the only way to 
store a function properly in a catalog or we need some 
serialization/deserialization logic in the function interfaces to 
convert an instance to string properties.


3. TableEnvironment: What is the signature of `register_function(self, 
name, function)`? Does it accept both a class and function? Like `class 
Sum` and `def split()`? Could you add some examples for registering both 
kinds of functions?


4. FunctionDefinition: Function definition is not a user-defined 
function definition. It is the highest interface for both user-defined 
and built-in functions. I'm not sure if getLanguage() should be part of 
this interface or one-level down which would be `UserDefinedFunction`. 
Built-in functions will never be implemented in a different language. In 
any case, I would vote for removing the UNKNOWN language, because it 
does not solve anything. Why should a user declare a function that the 
runtime can not handle? I also find the term `JAVA` confusing for Scala 
users. How about `FunctionLanguage.JVM` instead?


5. Function characteristics: In the current design, function classes do 
not extend from any upper class. How can users declare characteristics 
that are present in `FunctionDefinition` like determinism, requirements, 
or soon also monotonism.


Thanks,
Timo


On 02.09.19 03:38, Shaoxuan Wang wrote:

Hi Jincheng, Fudian, and Aljoscha,
I am assuming the proposed python UDX can also be applied to Flink SQL.
Is this correct? If yes, I would suggest to title the FLIP as "Flink Python
User-Defined Function" or "Flink Python User-Defined Function for Table".

Regards,
Shaoxuan


On Wed, Aug 28, 2019 at 12:22 PM jincheng sun 
wrote:


Thanks for the feedback Bowen!

Great thanks for create the FLIP and bring up the VOTE Dian!

Best, Jincheng

Dian Fu  于2019年8月28日周三 上午11:32写道：


Hi all,

I have started a voting thread [1]. Thanks a lot for your help during
creating the FLIP @Jincheng.


Hi Bowen,

Very appreciated for your comments. I have replied you in the design doc.
As it seems that the comments doesn't affect the overall design, I'll not
cancel the vote for now and we can continue the discussion in the design
doc.

[1]


http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/VOTE-FLIP-58-Flink-Python-User-Defined-Function-for-Table-API-td32295.html

<


http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/VOTE-FLIP-58-Flink-Python-User-Defined-Function-for-Table-API-td32295.html

Regards,
Dian


在 2019年8月28日，上午11:05，Bowen Li  写道：

Hi Jincheng and Dian,

Sorry for being late to the party. I took a glance at the proposal,

LGTM

in

general, and I left only a couple comments.

Thanks,
Bowen


On Mon, Aug 26, 2019 at 8:05 PM Dian Fu  wrote:


Hi Jincheng,

Thanks! It works.

Thanks,
Dian


在 2019年8月27日，上午10:55，jincheng sun  写道：

Hi Dian, can you check if you have edit access? :)


Dian Fu  于2019年8月26日周一 上午10:52写道：


Hi Jincheng,

Appreciated for the kind tips and offering of help. Definitely need

it!

Could you grant me write permission for confluence? My Id: Dian Fu

Thanks,
Dian


在 2019年8月26日，上午9:53，jincheng sun  写道：

Thanks for your feedback Hequn & Dian.

Dian, I am glad to see that you want help to create the FLIP!
Everyone will have first time, and I am very willing to help you

complete

your first FLIP creation. Here some tips:

- First I'll give your account write permission for confluence.
- Before create the FLIP, please have look at the FLIP Template

[1],

(It's

better to know more about FLIP by reading [2])
- Create Flink Python UDFs related JIRAs after completing the VOTE

of

FLIP.(I think you also can bring up the VOTE thread, if you want! )

Any problems you encounter during this period，feel free to tell me

that

we

can solve them together. :)

Best,
Jincheng




[1]

https://cwiki.apache.org/confluence/display/FLINK/FLIP+Template

[2]


https://cwiki.apache.org/confluence/display/FLINK/Flink+Improvement+Proposals


Hequn Cheng  于2019年8月23日周五 上午11:54写道：


+1 for starting the vote.

Thanks Jincheng a lot for the discussion.

Best, Hequn

On Fri, Aug 23, 2019 at 10:06 AM Dian Fu 

wrote:

Hi Jincheng,

+1 to start the FLIP create and VOTE on this feature. I'm willing

to

help

on the FLIP create if you don't mind. As I haven't created a FLIP

before,

it will be great if you could help on this. :)

Regards,
Dian


在 2019年8月22日，下午11:41，jincheng sun 

写道：

Hi all,

Thanks a 

Re: [DISCUSS] Flink Python User-Defined Function for Table API

[jincheng sun]

Thanks for the feedback Bowen!

Great thanks for create the FLIP and bring up the VOTE Dian!

Best, Jincheng

Dian Fu  于2019年8月28日周三 上午11:32写道：

> Hi all,
>
> I have started a voting thread [1]. Thanks a lot for your help during
> creating the FLIP @Jincheng.
>
>
> Hi Bowen,
>
> Very appreciated for your comments. I have replied you in the design doc.
> As it seems that the comments doesn't affect the overall design, I'll not
> cancel the vote for now and we can continue the discussion in the design
> doc.
>
> [1]
> http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/VOTE-FLIP-58-Flink-Python-User-Defined-Function-for-Table-API-td32295.html
> <
> http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/VOTE-FLIP-58-Flink-Python-User-Defined-Function-for-Table-API-td32295.html
> >
>
> Regards,
> Dian
>
> > 在 2019年8月28日，上午11:05，Bowen Li  写道：
> >
> > Hi Jincheng and Dian,
> >
> > Sorry for being late to the party. I took a glance at the proposal, LGTM
> in
> > general, and I left only a couple comments.
> >
> > Thanks,
> > Bowen
> >
> >
> > On Mon, Aug 26, 2019 at 8:05 PM Dian Fu  wrote:
> >
> >> Hi Jincheng,
> >>
> >> Thanks! It works.
> >>
> >> Thanks,
> >> Dian
> >>
> >>> 在 2019年8月27日，上午10:55，jincheng sun  写道：
> >>>
> >>> Hi Dian, can you check if you have edit access? :)
> >>>
> >>>
> >>> Dian Fu  于2019年8月26日周一 上午10:52写道：
> >>>
>  Hi Jincheng,
> 
>  Appreciated for the kind tips and offering of help. Definitely need
> it!
>  Could you grant me write permission for confluence? My Id: Dian Fu
> 
>  Thanks,
>  Dian
> 
> > 在 2019年8月26日，上午9:53，jincheng sun  写道：
> >
> > Thanks for your feedback Hequn & Dian.
> >
> > Dian, I am glad to see that you want help to create the FLIP!
> > Everyone will have first time, and I am very willing to help you
> >> complete
> > your first FLIP creation. Here some tips:
> >
> > - First I'll give your account write permission for confluence.
> > - Before create the FLIP, please have look at the FLIP Template [1],
>  (It's
> > better to know more about FLIP by reading [2])
> > - Create Flink Python UDFs related JIRAs after completing the VOTE of
> > FLIP.(I think you also can bring up the VOTE thread, if you want! )
> >
> > Any problems you encounter during this period，feel free to tell me
> that
>  we
> > can solve them together. :)
> >
> > Best,
> > Jincheng
> >
> >
> >
> >
> > [1] https://cwiki.apache.org/confluence/display/FLINK/FLIP+Template
> > [2]
> >
> 
> >>
> https://cwiki.apache.org/confluence/display/FLINK/Flink+Improvement+Proposals
> >
> >
> > Hequn Cheng  于2019年8月23日周五 上午11:54写道：
> >
> >> +1 for starting the vote.
> >>
> >> Thanks Jincheng a lot for the discussion.
> >>
> >> Best, Hequn
> >>
> >> On Fri, Aug 23, 2019 at 10:06 AM Dian Fu 
> >> wrote:
> >>
> >>> Hi Jincheng,
> >>>
> >>> +1 to start the FLIP create and VOTE on this feature. I'm willing
> to
>  help
> >>> on the FLIP create if you don't mind. As I haven't created a FLIP
>  before,
> >>> it will be great if you could help on this. :)
> >>>
> >>> Regards,
> >>> Dian
> >>>
>  在 2019年8月22日，下午11:41，jincheng sun  写道：
> 
>  Hi all,
> 
>  Thanks a lot for your feedback. If there are no more suggestions
> and
>  comments, I think it's better to  initiate a vote to create a FLIP
> >> for
>  Apache Flink Python UDFs.
>  What do you think?
> 
>  Best, Jincheng
> 
>  jincheng sun  于2019年8月15日周四 上午12:54写道：
> 
> > Hi Thomas,
> >
> > Thanks for your confirmation and the very important reminder
> about
> >>> bundle
> > processing.
> >
> > I have had add the description about how to perform bundle
> >> processing
> >>> from
> > the perspective of checkpoint and watermark. Feel free to leave
> >>> comments if
> > there are anything not describe clearly.
> >
> > Best,
> > Jincheng
> >
> >
> > Dian Fu  于2019年8月14日周三 上午10:08写道：
> >
> >> Hi Thomas,
> >>
> >> Thanks a lot the suggestions.
> >>
> >> Regarding to bundle processing, there is a section
> "Checkpoint"[1]
>  in
> >>> the
> >> design doc which talks about how to handle the checkpoint.
> >> However, I think you are right that we should talk more about
> it,
> >> such
> >>> as
> >> what's bundle processing, how it affects the checkpoint and
> >> watermark,
> >>> how
> >> to handle the checkpoint and watermark, etc.
> >>
> >> [1]
> >>
> >>>
> >>
> 
> >>
> 

Re: [DISCUSS] Flink Python User-Defined Function for Table API

[Dian Fu]

Hi all,

I have started a voting thread [1]. Thanks a lot for your help during creating 
the FLIP @Jincheng.


Hi Bowen,

Very appreciated for your comments. I have replied you in the design doc. As it 
seems that the comments doesn't affect the overall design, I'll not cancel the 
vote for now and we can continue the discussion in the design doc. 

[1] 
http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/VOTE-FLIP-58-Flink-Python-User-Defined-Function-for-Table-API-td32295.html
 


Regards,
Dian

> 在 2019年8月28日，上午11:05，Bowen Li  写道：
> 
> Hi Jincheng and Dian,
> 
> Sorry for being late to the party. I took a glance at the proposal, LGTM in
> general, and I left only a couple comments.
> 
> Thanks,
> Bowen
> 
> 
> On Mon, Aug 26, 2019 at 8:05 PM Dian Fu  wrote:
> 
>> Hi Jincheng,
>> 
>> Thanks! It works.
>> 
>> Thanks,
>> Dian
>> 
>>> 在 2019年8月27日，上午10:55，jincheng sun  写道：
>>> 
>>> Hi Dian, can you check if you have edit access? :)
>>> 
>>> 
>>> Dian Fu  于2019年8月26日周一 上午10:52写道：
>>> 
 Hi Jincheng,
 
 Appreciated for the kind tips and offering of help. Definitely need it!
 Could you grant me write permission for confluence? My Id: Dian Fu
 
 Thanks,
 Dian
 
> 在 2019年8月26日，上午9:53，jincheng sun  写道：
> 
> Thanks for your feedback Hequn & Dian.
> 
> Dian, I am glad to see that you want help to create the FLIP!
> Everyone will have first time, and I am very willing to help you
>> complete
> your first FLIP creation. Here some tips:
> 
> - First I'll give your account write permission for confluence.
> - Before create the FLIP, please have look at the FLIP Template [1],
 (It's
> better to know more about FLIP by reading [2])
> - Create Flink Python UDFs related JIRAs after completing the VOTE of
> FLIP.(I think you also can bring up the VOTE thread, if you want! )
> 
> Any problems you encounter during this period，feel free to tell me that
 we
> can solve them together. :)
> 
> Best,
> Jincheng
> 
> 
> 
> 
> [1] https://cwiki.apache.org/confluence/display/FLINK/FLIP+Template
> [2]
> 
 
>> https://cwiki.apache.org/confluence/display/FLINK/Flink+Improvement+Proposals
> 
> 
> Hequn Cheng  于2019年8月23日周五 上午11:54写道：
> 
>> +1 for starting the vote.
>> 
>> Thanks Jincheng a lot for the discussion.
>> 
>> Best, Hequn
>> 
>> On Fri, Aug 23, 2019 at 10:06 AM Dian Fu 
>> wrote:
>> 
>>> Hi Jincheng,
>>> 
>>> +1 to start the FLIP create and VOTE on this feature. I'm willing to
 help
>>> on the FLIP create if you don't mind. As I haven't created a FLIP
 before,
>>> it will be great if you could help on this. :)
>>> 
>>> Regards,
>>> Dian
>>> 
 在 2019年8月22日，下午11:41，jincheng sun  写道：
 
 Hi all,
 
 Thanks a lot for your feedback. If there are no more suggestions and
 comments, I think it's better to  initiate a vote to create a FLIP
>> for
 Apache Flink Python UDFs.
 What do you think?
 
 Best, Jincheng
 
 jincheng sun  于2019年8月15日周四 上午12:54写道：
 
> Hi Thomas,
> 
> Thanks for your confirmation and the very important reminder about
>>> bundle
> processing.
> 
> I have had add the description about how to perform bundle
>> processing
>>> from
> the perspective of checkpoint and watermark. Feel free to leave
>>> comments if
> there are anything not describe clearly.
> 
> Best,
> Jincheng
> 
> 
> Dian Fu  于2019年8月14日周三 上午10:08写道：
> 
>> Hi Thomas,
>> 
>> Thanks a lot the suggestions.
>> 
>> Regarding to bundle processing, there is a section "Checkpoint"[1]
 in
>>> the
>> design doc which talks about how to handle the checkpoint.
>> However, I think you are right that we should talk more about it,
>> such
>>> as
>> what's bundle processing, how it affects the checkpoint and
>> watermark,
>>> how
>> to handle the checkpoint and watermark, etc.
>> 
>> [1]
>> 
>>> 
>> 
 
>> https://docs.google.com/document/d/1WpTyCXAQh8Jr2yWfz7MWCD2-lou05QaQFb810ZvTefY/edit#heading=h.urladt565yo3
>> <
>> 
>>> 
>> 
 
>> https://docs.google.com/document/d/1WpTyCXAQh8Jr2yWfz7MWCD2-lou05QaQFb810ZvTefY/edit#heading=h.urladt565yo3
>>> 
>> 
>> Regards,
>> Dian
>> 
>>> 在 2019年8月14日，上午1:01，Thomas Weise  写道：
>>> 
>>> Hi Jincheng,
>>> 
>>> Thanks for putting this together. The proposal is very detailed,
>> 

Re: [DISCUSS] Flink Python User-Defined Function for Table API

[Bowen Li]

Hi Jincheng and Dian,

Sorry for being late to the party. I took a glance at the proposal, LGTM in
general, and I left only a couple comments.

Thanks,
Bowen


On Mon, Aug 26, 2019 at 8:05 PM Dian Fu  wrote:

> Hi Jincheng,
>
> Thanks! It works.
>
> Thanks,
> Dian
>
> > 在 2019年8月27日，上午10:55，jincheng sun  写道：
> >
> > Hi Dian, can you check if you have edit access? :)
> >
> >
> > Dian Fu  于2019年8月26日周一 上午10:52写道：
> >
> >> Hi Jincheng,
> >>
> >> Appreciated for the kind tips and offering of help. Definitely need it!
> >> Could you grant me write permission for confluence? My Id: Dian Fu
> >>
> >> Thanks,
> >> Dian
> >>
> >>> 在 2019年8月26日，上午9:53，jincheng sun  写道：
> >>>
> >>> Thanks for your feedback Hequn & Dian.
> >>>
> >>> Dian, I am glad to see that you want help to create the FLIP!
> >>> Everyone will have first time, and I am very willing to help you
> complete
> >>> your first FLIP creation. Here some tips:
> >>>
> >>> - First I'll give your account write permission for confluence.
> >>> - Before create the FLIP, please have look at the FLIP Template [1],
> >> (It's
> >>> better to know more about FLIP by reading [2])
> >>> - Create Flink Python UDFs related JIRAs after completing the VOTE of
> >>> FLIP.(I think you also can bring up the VOTE thread, if you want! )
> >>>
> >>> Any problems you encounter during this period，feel free to tell me that
> >> we
> >>> can solve them together. :)
> >>>
> >>> Best,
> >>> Jincheng
> >>>
> >>>
> >>>
> >>>
> >>> [1] https://cwiki.apache.org/confluence/display/FLINK/FLIP+Template
> >>> [2]
> >>>
> >>
> https://cwiki.apache.org/confluence/display/FLINK/Flink+Improvement+Proposals
> >>>
> >>>
> >>> Hequn Cheng  于2019年8月23日周五 上午11:54写道：
> >>>
>  +1 for starting the vote.
> 
>  Thanks Jincheng a lot for the discussion.
> 
>  Best, Hequn
> 
>  On Fri, Aug 23, 2019 at 10:06 AM Dian Fu 
> wrote:
> 
> > Hi Jincheng,
> >
> > +1 to start the FLIP create and VOTE on this feature. I'm willing to
> >> help
> > on the FLIP create if you don't mind. As I haven't created a FLIP
> >> before,
> > it will be great if you could help on this. :)
> >
> > Regards,
> > Dian
> >
> >> 在 2019年8月22日，下午11:41，jincheng sun  写道：
> >>
> >> Hi all,
> >>
> >> Thanks a lot for your feedback. If there are no more suggestions and
> >> comments, I think it's better to  initiate a vote to create a FLIP
> for
> >> Apache Flink Python UDFs.
> >> What do you think?
> >>
> >> Best, Jincheng
> >>
> >> jincheng sun  于2019年8月15日周四 上午12:54写道：
> >>
> >>> Hi Thomas,
> >>>
> >>> Thanks for your confirmation and the very important reminder about
> > bundle
> >>> processing.
> >>>
> >>> I have had add the description about how to perform bundle
> processing
> > from
> >>> the perspective of checkpoint and watermark. Feel free to leave
> > comments if
> >>> there are anything not describe clearly.
> >>>
> >>> Best,
> >>> Jincheng
> >>>
> >>>
> >>> Dian Fu  于2019年8月14日周三 上午10:08写道：
> >>>
>  Hi Thomas,
> 
>  Thanks a lot the suggestions.
> 
>  Regarding to bundle processing, there is a section "Checkpoint"[1]
> >> in
> > the
>  design doc which talks about how to handle the checkpoint.
>  However, I think you are right that we should talk more about it,
>  such
> > as
>  what's bundle processing, how it affects the checkpoint and
>  watermark,
> > how
>  to handle the checkpoint and watermark, etc.
> 
>  [1]
> 
> >
> 
> >>
> https://docs.google.com/document/d/1WpTyCXAQh8Jr2yWfz7MWCD2-lou05QaQFb810ZvTefY/edit#heading=h.urladt565yo3
>  <
> 
> >
> 
> >>
> https://docs.google.com/document/d/1WpTyCXAQh8Jr2yWfz7MWCD2-lou05QaQFb810ZvTefY/edit#heading=h.urladt565yo3
> >
> 
>  Regards,
>  Dian
> 
> > 在 2019年8月14日，上午1:01，Thomas Weise  写道：
> >
> > Hi Jincheng,
> >
> > Thanks for putting this together. The proposal is very detailed,
>  thorough
> > and for me as a Beam Flink runner contributor easy to understand
> :)
> >
> > One thing that you should probably detail more is the bundle
>  processing. It
> > is critically important for performance that multiple elements
> are
> > processed in a bundle. The default bundle size in the Flink
> runner
>  is
>  1s or
> > 1000 elements, whichever comes first. And for streaming, you can
>  find
>  the
> > logic necessary to align the bundle processing with watermarks
> and
> > checkpointing here:
> >
> 
> >
> 
> >>
> 

Re: [DISCUSS] Flink Python User-Defined Function for Table API

[Dian Fu]

Hi Jincheng,

Thanks! It works.

Thanks,
Dian

> 在 2019年8月27日，上午10:55，jincheng sun  写道：
> 
> Hi Dian, can you check if you have edit access? :)
> 
> 
> Dian Fu  于2019年8月26日周一 上午10:52写道：
> 
>> Hi Jincheng,
>> 
>> Appreciated for the kind tips and offering of help. Definitely need it!
>> Could you grant me write permission for confluence? My Id: Dian Fu
>> 
>> Thanks,
>> Dian
>> 
>>> 在 2019年8月26日，上午9:53，jincheng sun  写道：
>>> 
>>> Thanks for your feedback Hequn & Dian.
>>> 
>>> Dian, I am glad to see that you want help to create the FLIP!
>>> Everyone will have first time, and I am very willing to help you complete
>>> your first FLIP creation. Here some tips:
>>> 
>>> - First I'll give your account write permission for confluence.
>>> - Before create the FLIP, please have look at the FLIP Template [1],
>> (It's
>>> better to know more about FLIP by reading [2])
>>> - Create Flink Python UDFs related JIRAs after completing the VOTE of
>>> FLIP.(I think you also can bring up the VOTE thread, if you want! )
>>> 
>>> Any problems you encounter during this period，feel free to tell me that
>> we
>>> can solve them together. :)
>>> 
>>> Best,
>>> Jincheng
>>> 
>>> 
>>> 
>>> 
>>> [1] https://cwiki.apache.org/confluence/display/FLINK/FLIP+Template
>>> [2]
>>> 
>> https://cwiki.apache.org/confluence/display/FLINK/Flink+Improvement+Proposals
>>> 
>>> 
>>> Hequn Cheng  于2019年8月23日周五 上午11:54写道：
>>> 
 +1 for starting the vote.
 
 Thanks Jincheng a lot for the discussion.
 
 Best, Hequn
 
 On Fri, Aug 23, 2019 at 10:06 AM Dian Fu  wrote:
 
> Hi Jincheng,
> 
> +1 to start the FLIP create and VOTE on this feature. I'm willing to
>> help
> on the FLIP create if you don't mind. As I haven't created a FLIP
>> before,
> it will be great if you could help on this. :)
> 
> Regards,
> Dian
> 
>> 在 2019年8月22日，下午11:41，jincheng sun  写道：
>> 
>> Hi all,
>> 
>> Thanks a lot for your feedback. If there are no more suggestions and
>> comments, I think it's better to  initiate a vote to create a FLIP for
>> Apache Flink Python UDFs.
>> What do you think?
>> 
>> Best, Jincheng
>> 
>> jincheng sun  于2019年8月15日周四 上午12:54写道：
>> 
>>> Hi Thomas,
>>> 
>>> Thanks for your confirmation and the very important reminder about
> bundle
>>> processing.
>>> 
>>> I have had add the description about how to perform bundle processing
> from
>>> the perspective of checkpoint and watermark. Feel free to leave
> comments if
>>> there are anything not describe clearly.
>>> 
>>> Best,
>>> Jincheng
>>> 
>>> 
>>> Dian Fu  于2019年8月14日周三 上午10:08写道：
>>> 
 Hi Thomas,
 
 Thanks a lot the suggestions.
 
 Regarding to bundle processing, there is a section "Checkpoint"[1]
>> in
> the
 design doc which talks about how to handle the checkpoint.
 However, I think you are right that we should talk more about it,
 such
> as
 what's bundle processing, how it affects the checkpoint and
 watermark,
> how
 to handle the checkpoint and watermark, etc.
 
 [1]
 
> 
 
>> https://docs.google.com/document/d/1WpTyCXAQh8Jr2yWfz7MWCD2-lou05QaQFb810ZvTefY/edit#heading=h.urladt565yo3
 <
 
> 
 
>> https://docs.google.com/document/d/1WpTyCXAQh8Jr2yWfz7MWCD2-lou05QaQFb810ZvTefY/edit#heading=h.urladt565yo3
> 
 
 Regards,
 Dian
 
> 在 2019年8月14日，上午1:01，Thomas Weise  写道：
> 
> Hi Jincheng,
> 
> Thanks for putting this together. The proposal is very detailed,
 thorough
> and for me as a Beam Flink runner contributor easy to understand :)
> 
> One thing that you should probably detail more is the bundle
 processing. It
> is critically important for performance that multiple elements are
> processed in a bundle. The default bundle size in the Flink runner
 is
 1s or
> 1000 elements, whichever comes first. And for streaming, you can
 find
 the
> logic necessary to align the bundle processing with watermarks and
> checkpointing here:
> 
 
> 
 
>> https://github.com/apache/beam/blob/release-2.14.0/runners/flink/src/main/java/org/apache/beam/runners/flink/translation/wrappers/streaming/ExecutableStageDoFnOperator.java
> 
> Thomas
> 
> 
> 
> 
> 
> 
> 
> On Tue, Aug 13, 2019 at 7:05 AM jincheng sun <
> sunjincheng...@gmail.com>
> wrote:
> 
>> Hi all,
>> 
>> The Python Table API(without Python UDF support) has already been
 supported
>> and will be available in the coming release 1.9.
>> As Python UDF is very important for 

Re: [DISCUSS] Flink Python User-Defined Function for Table API

[jincheng sun]

Hi Dian, can you check if you have edit access? :)


Dian Fu  于2019年8月26日周一 上午10:52写道：

> Hi Jincheng,
>
> Appreciated for the kind tips and offering of help. Definitely need it!
> Could you grant me write permission for confluence? My Id: Dian Fu
>
> Thanks,
> Dian
>
> > 在 2019年8月26日，上午9:53，jincheng sun  写道：
> >
> > Thanks for your feedback Hequn & Dian.
> >
> > Dian, I am glad to see that you want help to create the FLIP!
> > Everyone will have first time, and I am very willing to help you complete
> > your first FLIP creation. Here some tips:
> >
> > - First I'll give your account write permission for confluence.
> > - Before create the FLIP, please have look at the FLIP Template [1],
> (It's
> > better to know more about FLIP by reading [2])
> > - Create Flink Python UDFs related JIRAs after completing the VOTE of
> > FLIP.(I think you also can bring up the VOTE thread, if you want! )
> >
> > Any problems you encounter during this period，feel free to tell me that
> we
> > can solve them together. :)
> >
> > Best,
> > Jincheng
> >
> >
> >
> >
> > [1] https://cwiki.apache.org/confluence/display/FLINK/FLIP+Template
> > [2]
> >
> https://cwiki.apache.org/confluence/display/FLINK/Flink+Improvement+Proposals
> >
> >
> > Hequn Cheng  于2019年8月23日周五 上午11:54写道：
> >
> >> +1 for starting the vote.
> >>
> >> Thanks Jincheng a lot for the discussion.
> >>
> >> Best, Hequn
> >>
> >> On Fri, Aug 23, 2019 at 10:06 AM Dian Fu  wrote:
> >>
> >>> Hi Jincheng,
> >>>
> >>> +1 to start the FLIP create and VOTE on this feature. I'm willing to
> help
> >>> on the FLIP create if you don't mind. As I haven't created a FLIP
> before,
> >>> it will be great if you could help on this. :)
> >>>
> >>> Regards,
> >>> Dian
> >>>
>  在 2019年8月22日，下午11:41，jincheng sun  写道：
> 
>  Hi all,
> 
>  Thanks a lot for your feedback. If there are no more suggestions and
>  comments, I think it's better to  initiate a vote to create a FLIP for
>  Apache Flink Python UDFs.
>  What do you think?
> 
>  Best, Jincheng
> 
>  jincheng sun  于2019年8月15日周四 上午12:54写道：
> 
> > Hi Thomas,
> >
> > Thanks for your confirmation and the very important reminder about
> >>> bundle
> > processing.
> >
> > I have had add the description about how to perform bundle processing
> >>> from
> > the perspective of checkpoint and watermark. Feel free to leave
> >>> comments if
> > there are anything not describe clearly.
> >
> > Best,
> > Jincheng
> >
> >
> > Dian Fu  于2019年8月14日周三 上午10:08写道：
> >
> >> Hi Thomas,
> >>
> >> Thanks a lot the suggestions.
> >>
> >> Regarding to bundle processing, there is a section "Checkpoint"[1]
> in
> >>> the
> >> design doc which talks about how to handle the checkpoint.
> >> However, I think you are right that we should talk more about it,
> >> such
> >>> as
> >> what's bundle processing, how it affects the checkpoint and
> >> watermark,
> >>> how
> >> to handle the checkpoint and watermark, etc.
> >>
> >> [1]
> >>
> >>>
> >>
> https://docs.google.com/document/d/1WpTyCXAQh8Jr2yWfz7MWCD2-lou05QaQFb810ZvTefY/edit#heading=h.urladt565yo3
> >> <
> >>
> >>>
> >>
> https://docs.google.com/document/d/1WpTyCXAQh8Jr2yWfz7MWCD2-lou05QaQFb810ZvTefY/edit#heading=h.urladt565yo3
> >>>
> >>
> >> Regards,
> >> Dian
> >>
> >>> 在 2019年8月14日，上午1:01，Thomas Weise  写道：
> >>>
> >>> Hi Jincheng,
> >>>
> >>> Thanks for putting this together. The proposal is very detailed,
> >> thorough
> >>> and for me as a Beam Flink runner contributor easy to understand :)
> >>>
> >>> One thing that you should probably detail more is the bundle
> >> processing. It
> >>> is critically important for performance that multiple elements are
> >>> processed in a bundle. The default bundle size in the Flink runner
> >> is
> >> 1s or
> >>> 1000 elements, whichever comes first. And for streaming, you can
> >> find
> >> the
> >>> logic necessary to align the bundle processing with watermarks and
> >>> checkpointing here:
> >>>
> >>
> >>>
> >>
> https://github.com/apache/beam/blob/release-2.14.0/runners/flink/src/main/java/org/apache/beam/runners/flink/translation/wrappers/streaming/ExecutableStageDoFnOperator.java
> >>>
> >>> Thomas
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> On Tue, Aug 13, 2019 at 7:05 AM jincheng sun <
> >>> sunjincheng...@gmail.com>
> >>> wrote:
> >>>
>  Hi all,
> 
>  The Python Table API(without Python UDF support) has already been
> >> supported
>  and will be available in the coming release 1.9.
>  As Python UDF is very important for Python users, we'd like to
> >> start
> >> the
>  discussion about the Python UDF support in the Python Table API.
>  Aljoscha Krettek, Dian Fu and I have discussed 

Re: [DISCUSS] Flink Python User-Defined Function for Table API

[Dian Fu]

Hi Jincheng,

Appreciated for the kind tips and offering of help. Definitely need it! Could 
you grant me write permission for confluence? My Id: Dian Fu

Thanks,
Dian

> 在 2019年8月26日，上午9:53，jincheng sun  写道：
> 
> Thanks for your feedback Hequn & Dian.
> 
> Dian, I am glad to see that you want help to create the FLIP!
> Everyone will have first time, and I am very willing to help you complete
> your first FLIP creation. Here some tips:
> 
> - First I'll give your account write permission for confluence.
> - Before create the FLIP, please have look at the FLIP Template [1], (It's
> better to know more about FLIP by reading [2])
> - Create Flink Python UDFs related JIRAs after completing the VOTE of
> FLIP.(I think you also can bring up the VOTE thread, if you want! )
> 
> Any problems you encounter during this period，feel free to tell me that we
> can solve them together. :)
> 
> Best,
> Jincheng
> 
> 
> 
> 
> [1] https://cwiki.apache.org/confluence/display/FLINK/FLIP+Template
> [2]
> https://cwiki.apache.org/confluence/display/FLINK/Flink+Improvement+Proposals
> 
> 
> Hequn Cheng  于2019年8月23日周五 上午11:54写道：
> 
>> +1 for starting the vote.
>> 
>> Thanks Jincheng a lot for the discussion.
>> 
>> Best, Hequn
>> 
>> On Fri, Aug 23, 2019 at 10:06 AM Dian Fu  wrote:
>> 
>>> Hi Jincheng,
>>> 
>>> +1 to start the FLIP create and VOTE on this feature. I'm willing to help
>>> on the FLIP create if you don't mind. As I haven't created a FLIP before,
>>> it will be great if you could help on this. :)
>>> 
>>> Regards,
>>> Dian
>>> 
 在 2019年8月22日，下午11:41，jincheng sun  写道：
 
 Hi all,
 
 Thanks a lot for your feedback. If there are no more suggestions and
 comments, I think it's better to  initiate a vote to create a FLIP for
 Apache Flink Python UDFs.
 What do you think?
 
 Best, Jincheng
 
 jincheng sun  于2019年8月15日周四 上午12:54写道：
 
> Hi Thomas,
> 
> Thanks for your confirmation and the very important reminder about
>>> bundle
> processing.
> 
> I have had add the description about how to perform bundle processing
>>> from
> the perspective of checkpoint and watermark. Feel free to leave
>>> comments if
> there are anything not describe clearly.
> 
> Best,
> Jincheng
> 
> 
> Dian Fu  于2019年8月14日周三 上午10:08写道：
> 
>> Hi Thomas,
>> 
>> Thanks a lot the suggestions.
>> 
>> Regarding to bundle processing, there is a section "Checkpoint"[1] in
>>> the
>> design doc which talks about how to handle the checkpoint.
>> However, I think you are right that we should talk more about it,
>> such
>>> as
>> what's bundle processing, how it affects the checkpoint and
>> watermark,
>>> how
>> to handle the checkpoint and watermark, etc.
>> 
>> [1]
>> 
>>> 
>> https://docs.google.com/document/d/1WpTyCXAQh8Jr2yWfz7MWCD2-lou05QaQFb810ZvTefY/edit#heading=h.urladt565yo3
>> <
>> 
>>> 
>> https://docs.google.com/document/d/1WpTyCXAQh8Jr2yWfz7MWCD2-lou05QaQFb810ZvTefY/edit#heading=h.urladt565yo3
>>> 
>> 
>> Regards,
>> Dian
>> 
>>> 在 2019年8月14日，上午1:01，Thomas Weise  写道：
>>> 
>>> Hi Jincheng,
>>> 
>>> Thanks for putting this together. The proposal is very detailed,
>> thorough
>>> and for me as a Beam Flink runner contributor easy to understand :)
>>> 
>>> One thing that you should probably detail more is the bundle
>> processing. It
>>> is critically important for performance that multiple elements are
>>> processed in a bundle. The default bundle size in the Flink runner
>> is
>> 1s or
>>> 1000 elements, whichever comes first. And for streaming, you can
>> find
>> the
>>> logic necessary to align the bundle processing with watermarks and
>>> checkpointing here:
>>> 
>> 
>>> 
>> https://github.com/apache/beam/blob/release-2.14.0/runners/flink/src/main/java/org/apache/beam/runners/flink/translation/wrappers/streaming/ExecutableStageDoFnOperator.java
>>> 
>>> Thomas
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> On Tue, Aug 13, 2019 at 7:05 AM jincheng sun <
>>> sunjincheng...@gmail.com>
>>> wrote:
>>> 
 Hi all,
 
 The Python Table API(without Python UDF support) has already been
>> supported
 and will be available in the coming release 1.9.
 As Python UDF is very important for Python users, we'd like to
>> start
>> the
 discussion about the Python UDF support in the Python Table API.
 Aljoscha Krettek, Dian Fu and I have discussed offline and have
>> drafted a
 design doc[1]. It includes the following items:
 
 - The user-defined function interfaces.
 - The user-defined function execution architecture.
 
 As mentioned by many guys in the previous discussion thread[2], a
 portability framework was introduced in Apache Beam in 

Re: [DISCUSS] Flink Python User-Defined Function for Table API

[jincheng sun]

Thanks for your feedback Hequn & Dian.

Dian, I am glad to see that you want help to create the FLIP!
Everyone will have first time, and I am very willing to help you complete
your first FLIP creation. Here some tips:

- First I'll give your account write permission for confluence.
- Before create the FLIP, please have look at the FLIP Template [1], (It's
better to know more about FLIP by reading [2])
- Create Flink Python UDFs related JIRAs after completing the VOTE of
FLIP.(I think you also can bring up the VOTE thread, if you want! )

Any problems you encounter during this period，feel free to tell me that we
can solve them together. :)

Best,
Jincheng




[1] https://cwiki.apache.org/confluence/display/FLINK/FLIP+Template
[2]
https://cwiki.apache.org/confluence/display/FLINK/Flink+Improvement+Proposals


Hequn Cheng  于2019年8月23日周五 上午11:54写道：

> +1 for starting the vote.
>
> Thanks Jincheng a lot for the discussion.
>
> Best, Hequn
>
> On Fri, Aug 23, 2019 at 10:06 AM Dian Fu  wrote:
>
> > Hi Jincheng,
> >
> > +1 to start the FLIP create and VOTE on this feature. I'm willing to help
> > on the FLIP create if you don't mind. As I haven't created a FLIP before,
> > it will be great if you could help on this. :)
> >
> > Regards,
> > Dian
> >
> > > 在 2019年8月22日，下午11:41，jincheng sun  写道：
> > >
> > > Hi all,
> > >
> > > Thanks a lot for your feedback. If there are no more suggestions and
> > > comments, I think it's better to  initiate a vote to create a FLIP for
> > > Apache Flink Python UDFs.
> > > What do you think?
> > >
> > > Best, Jincheng
> > >
> > > jincheng sun  于2019年8月15日周四 上午12:54写道：
> > >
> > >> Hi Thomas,
> > >>
> > >> Thanks for your confirmation and the very important reminder about
> > bundle
> > >> processing.
> > >>
> > >> I have had add the description about how to perform bundle processing
> > from
> > >> the perspective of checkpoint and watermark. Feel free to leave
> > comments if
> > >> there are anything not describe clearly.
> > >>
> > >> Best,
> > >> Jincheng
> > >>
> > >>
> > >> Dian Fu  于2019年8月14日周三 上午10:08写道：
> > >>
> > >>> Hi Thomas,
> > >>>
> > >>> Thanks a lot the suggestions.
> > >>>
> > >>> Regarding to bundle processing, there is a section "Checkpoint"[1] in
> > the
> > >>> design doc which talks about how to handle the checkpoint.
> > >>> However, I think you are right that we should talk more about it,
> such
> > as
> > >>> what's bundle processing, how it affects the checkpoint and
> watermark,
> > how
> > >>> to handle the checkpoint and watermark, etc.
> > >>>
> > >>> [1]
> > >>>
> >
> https://docs.google.com/document/d/1WpTyCXAQh8Jr2yWfz7MWCD2-lou05QaQFb810ZvTefY/edit#heading=h.urladt565yo3
> > >>> <
> > >>>
> >
> https://docs.google.com/document/d/1WpTyCXAQh8Jr2yWfz7MWCD2-lou05QaQFb810ZvTefY/edit#heading=h.urladt565yo3
> > 
> > >>>
> > >>> Regards,
> > >>> Dian
> > >>>
> >  在 2019年8月14日，上午1:01，Thomas Weise  写道：
> > 
> >  Hi Jincheng,
> > 
> >  Thanks for putting this together. The proposal is very detailed,
> > >>> thorough
> >  and for me as a Beam Flink runner contributor easy to understand :)
> > 
> >  One thing that you should probably detail more is the bundle
> > >>> processing. It
> >  is critically important for performance that multiple elements are
> >  processed in a bundle. The default bundle size in the Flink runner
> is
> > >>> 1s or
> >  1000 elements, whichever comes first. And for streaming, you can
> find
> > >>> the
> >  logic necessary to align the bundle processing with watermarks and
> >  checkpointing here:
> > 
> > >>>
> >
> https://github.com/apache/beam/blob/release-2.14.0/runners/flink/src/main/java/org/apache/beam/runners/flink/translation/wrappers/streaming/ExecutableStageDoFnOperator.java
> > 
> >  Thomas
> > 
> > 
> > 
> > 
> > 
> > 
> > 
> >  On Tue, Aug 13, 2019 at 7:05 AM jincheng sun <
> > sunjincheng...@gmail.com>
> >  wrote:
> > 
> > > Hi all,
> > >
> > > The Python Table API(without Python UDF support) has already been
> > >>> supported
> > > and will be available in the coming release 1.9.
> > > As Python UDF is very important for Python users, we'd like to
> start
> > >>> the
> > > discussion about the Python UDF support in the Python Table API.
> > > Aljoscha Krettek, Dian Fu and I have discussed offline and have
> > >>> drafted a
> > > design doc[1]. It includes the following items:
> > >
> > > - The user-defined function interfaces.
> > > - The user-defined function execution architecture.
> > >
> > > As mentioned by many guys in the previous discussion thread[2], a
> > > portability framework was introduced in Apache Beam in latest
> > >>> releases. It
> > > provides well-defined, language-neutral data structures and
> protocols
> > >>> for
> > > language-neutral user-defined function execution. This design is
> > based
> > >>> on
> > > Beam's 

Re: [DISCUSS] Flink Python User-Defined Function for Table API

[Hequn Cheng]

+1 for starting the vote.

Thanks Jincheng a lot for the discussion.

Best, Hequn

On Fri, Aug 23, 2019 at 10:06 AM Dian Fu  wrote:

> Hi Jincheng,
>
> +1 to start the FLIP create and VOTE on this feature. I'm willing to help
> on the FLIP create if you don't mind. As I haven't created a FLIP before,
> it will be great if you could help on this. :)
>
> Regards,
> Dian
>
> > 在 2019年8月22日，下午11:41，jincheng sun  写道：
> >
> > Hi all,
> >
> > Thanks a lot for your feedback. If there are no more suggestions and
> > comments, I think it's better to  initiate a vote to create a FLIP for
> > Apache Flink Python UDFs.
> > What do you think?
> >
> > Best, Jincheng
> >
> > jincheng sun  于2019年8月15日周四 上午12:54写道：
> >
> >> Hi Thomas,
> >>
> >> Thanks for your confirmation and the very important reminder about
> bundle
> >> processing.
> >>
> >> I have had add the description about how to perform bundle processing
> from
> >> the perspective of checkpoint and watermark. Feel free to leave
> comments if
> >> there are anything not describe clearly.
> >>
> >> Best,
> >> Jincheng
> >>
> >>
> >> Dian Fu  于2019年8月14日周三 上午10:08写道：
> >>
> >>> Hi Thomas,
> >>>
> >>> Thanks a lot the suggestions.
> >>>
> >>> Regarding to bundle processing, there is a section "Checkpoint"[1] in
> the
> >>> design doc which talks about how to handle the checkpoint.
> >>> However, I think you are right that we should talk more about it, such
> as
> >>> what's bundle processing, how it affects the checkpoint and watermark,
> how
> >>> to handle the checkpoint and watermark, etc.
> >>>
> >>> [1]
> >>>
> https://docs.google.com/document/d/1WpTyCXAQh8Jr2yWfz7MWCD2-lou05QaQFb810ZvTefY/edit#heading=h.urladt565yo3
> >>> <
> >>>
> https://docs.google.com/document/d/1WpTyCXAQh8Jr2yWfz7MWCD2-lou05QaQFb810ZvTefY/edit#heading=h.urladt565yo3
> 
> >>>
> >>> Regards,
> >>> Dian
> >>>
>  在 2019年8月14日，上午1:01，Thomas Weise  写道：
> 
>  Hi Jincheng,
> 
>  Thanks for putting this together. The proposal is very detailed,
> >>> thorough
>  and for me as a Beam Flink runner contributor easy to understand :)
> 
>  One thing that you should probably detail more is the bundle
> >>> processing. It
>  is critically important for performance that multiple elements are
>  processed in a bundle. The default bundle size in the Flink runner is
> >>> 1s or
>  1000 elements, whichever comes first. And for streaming, you can find
> >>> the
>  logic necessary to align the bundle processing with watermarks and
>  checkpointing here:
> 
> >>>
> https://github.com/apache/beam/blob/release-2.14.0/runners/flink/src/main/java/org/apache/beam/runners/flink/translation/wrappers/streaming/ExecutableStageDoFnOperator.java
> 
>  Thomas
> 
> 
> 
> 
> 
> 
> 
>  On Tue, Aug 13, 2019 at 7:05 AM jincheng sun <
> sunjincheng...@gmail.com>
>  wrote:
> 
> > Hi all,
> >
> > The Python Table API(without Python UDF support) has already been
> >>> supported
> > and will be available in the coming release 1.9.
> > As Python UDF is very important for Python users, we'd like to start
> >>> the
> > discussion about the Python UDF support in the Python Table API.
> > Aljoscha Krettek, Dian Fu and I have discussed offline and have
> >>> drafted a
> > design doc[1]. It includes the following items:
> >
> > - The user-defined function interfaces.
> > - The user-defined function execution architecture.
> >
> > As mentioned by many guys in the previous discussion thread[2], a
> > portability framework was introduced in Apache Beam in latest
> >>> releases. It
> > provides well-defined, language-neutral data structures and protocols
> >>> for
> > language-neutral user-defined function execution. This design is
> based
> >>> on
> > Beam's portability framework. We will introduce how to make use of
> >>> Beam's
> > portability framework for user-defined function execution: data
> > transmission, state access, checkpoint, metrics, logging, etc.
> >
> > Considering that the design relies on Beam's portability framework
> for
> > Python user-defined function execution and not all the contributors
> in
> > Flink community are familiar with Beam's portability framework, we
> have
> > done a prototype[3] for proof of concept and also ease of
> >>> understanding of
> > the design.
> >
> > Welcome any feedback.
> >
> > Best,
> > Jincheng
> >
> > [1]
> >
> >
> >>>
> https://docs.google.com/document/d/1WpTyCXAQh8Jr2yWfz7MWCD2-lou05QaQFb810ZvTefY/edit?usp=sharing
> > [2]
> >
> >
> >>>
> http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/DISCUSS-FLIP-38-Support-python-language-in-flink-TableAPI-td28061.html
> > [3] https://github.com/dianfu/flink/commits/udf_poc
> >
> >>>
> >>>
>
>

Re: [DISCUSS] Flink Python User-Defined Function for Table API

[Dian Fu]

Hi Jincheng,

+1 to start the FLIP create and VOTE on this feature. I'm willing to help on 
the FLIP create if you don't mind. As I haven't created a FLIP before, it will 
be great if you could help on this. :)

Regards,
Dian

> 在 2019年8月22日，下午11:41，jincheng sun  写道：
> 
> Hi all,
> 
> Thanks a lot for your feedback. If there are no more suggestions and
> comments, I think it's better to  initiate a vote to create a FLIP for
> Apache Flink Python UDFs.
> What do you think?
> 
> Best, Jincheng
> 
> jincheng sun  于2019年8月15日周四 上午12:54写道：
> 
>> Hi Thomas,
>> 
>> Thanks for your confirmation and the very important reminder about bundle
>> processing.
>> 
>> I have had add the description about how to perform bundle processing from
>> the perspective of checkpoint and watermark. Feel free to leave comments if
>> there are anything not describe clearly.
>> 
>> Best,
>> Jincheng
>> 
>> 
>> Dian Fu  于2019年8月14日周三 上午10:08写道：
>> 
>>> Hi Thomas,
>>> 
>>> Thanks a lot the suggestions.
>>> 
>>> Regarding to bundle processing, there is a section "Checkpoint"[1] in the
>>> design doc which talks about how to handle the checkpoint.
>>> However, I think you are right that we should talk more about it, such as
>>> what's bundle processing, how it affects the checkpoint and watermark, how
>>> to handle the checkpoint and watermark, etc.
>>> 
>>> [1]
>>> https://docs.google.com/document/d/1WpTyCXAQh8Jr2yWfz7MWCD2-lou05QaQFb810ZvTefY/edit#heading=h.urladt565yo3
>>> <
>>> https://docs.google.com/document/d/1WpTyCXAQh8Jr2yWfz7MWCD2-lou05QaQFb810ZvTefY/edit#heading=h.urladt565yo3
 
>>> 
>>> Regards,
>>> Dian
>>> 
 在 2019年8月14日，上午1:01，Thomas Weise  写道：
 
 Hi Jincheng,
 
 Thanks for putting this together. The proposal is very detailed,
>>> thorough
 and for me as a Beam Flink runner contributor easy to understand :)
 
 One thing that you should probably detail more is the bundle
>>> processing. It
 is critically important for performance that multiple elements are
 processed in a bundle. The default bundle size in the Flink runner is
>>> 1s or
 1000 elements, whichever comes first. And for streaming, you can find
>>> the
 logic necessary to align the bundle processing with watermarks and
 checkpointing here:
 
>>> https://github.com/apache/beam/blob/release-2.14.0/runners/flink/src/main/java/org/apache/beam/runners/flink/translation/wrappers/streaming/ExecutableStageDoFnOperator.java
 
 Thomas
 
 
 
 
 
 
 
 On Tue, Aug 13, 2019 at 7:05 AM jincheng sun 
 wrote:
 
> Hi all,
> 
> The Python Table API(without Python UDF support) has already been
>>> supported
> and will be available in the coming release 1.9.
> As Python UDF is very important for Python users, we'd like to start
>>> the
> discussion about the Python UDF support in the Python Table API.
> Aljoscha Krettek, Dian Fu and I have discussed offline and have
>>> drafted a
> design doc[1]. It includes the following items:
> 
> - The user-defined function interfaces.
> - The user-defined function execution architecture.
> 
> As mentioned by many guys in the previous discussion thread[2], a
> portability framework was introduced in Apache Beam in latest
>>> releases. It
> provides well-defined, language-neutral data structures and protocols
>>> for
> language-neutral user-defined function execution. This design is based
>>> on
> Beam's portability framework. We will introduce how to make use of
>>> Beam's
> portability framework for user-defined function execution: data
> transmission, state access, checkpoint, metrics, logging, etc.
> 
> Considering that the design relies on Beam's portability framework for
> Python user-defined function execution and not all the contributors in
> Flink community are familiar with Beam's portability framework, we have
> done a prototype[3] for proof of concept and also ease of
>>> understanding of
> the design.
> 
> Welcome any feedback.
> 
> Best,
> Jincheng
> 
> [1]
> 
> 
>>> https://docs.google.com/document/d/1WpTyCXAQh8Jr2yWfz7MWCD2-lou05QaQFb810ZvTefY/edit?usp=sharing
> [2]
> 
> 
>>> http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/DISCUSS-FLIP-38-Support-python-language-in-flink-TableAPI-td28061.html
> [3] https://github.com/dianfu/flink/commits/udf_poc
> 
>>> 
>>> 

Re: [DISCUSS] Flink Python User-Defined Function for Table API

[jincheng sun]

Hi all,

Thanks a lot for your feedback. If there are no more suggestions and
comments, I think it's better to  initiate a vote to create a FLIP for
Apache Flink Python UDFs.
What do you think?

Best, Jincheng

jincheng sun  于2019年8月15日周四 上午12:54写道：

> Hi Thomas,
>
> Thanks for your confirmation and the very important reminder about bundle
> processing.
>
> I have had add the description about how to perform bundle processing from
> the perspective of checkpoint and watermark. Feel free to leave comments if
> there are anything not describe clearly.
>
> Best,
> Jincheng
>
>
> Dian Fu  于2019年8月14日周三 上午10:08写道：
>
>> Hi Thomas,
>>
>> Thanks a lot the suggestions.
>>
>> Regarding to bundle processing, there is a section "Checkpoint"[1] in the
>> design doc which talks about how to handle the checkpoint.
>> However, I think you are right that we should talk more about it, such as
>> what's bundle processing, how it affects the checkpoint and watermark, how
>> to handle the checkpoint and watermark, etc.
>>
>> [1]
>> https://docs.google.com/document/d/1WpTyCXAQh8Jr2yWfz7MWCD2-lou05QaQFb810ZvTefY/edit#heading=h.urladt565yo3
>> <
>> https://docs.google.com/document/d/1WpTyCXAQh8Jr2yWfz7MWCD2-lou05QaQFb810ZvTefY/edit#heading=h.urladt565yo3
>> >
>>
>> Regards,
>> Dian
>>
>> > 在 2019年8月14日，上午1:01，Thomas Weise  写道：
>> >
>> > Hi Jincheng,
>> >
>> > Thanks for putting this together. The proposal is very detailed,
>> thorough
>> > and for me as a Beam Flink runner contributor easy to understand :)
>> >
>> > One thing that you should probably detail more is the bundle
>> processing. It
>> > is critically important for performance that multiple elements are
>> > processed in a bundle. The default bundle size in the Flink runner is
>> 1s or
>> > 1000 elements, whichever comes first. And for streaming, you can find
>> the
>> > logic necessary to align the bundle processing with watermarks and
>> > checkpointing here:
>> >
>> https://github.com/apache/beam/blob/release-2.14.0/runners/flink/src/main/java/org/apache/beam/runners/flink/translation/wrappers/streaming/ExecutableStageDoFnOperator.java
>> >
>> > Thomas
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> > On Tue, Aug 13, 2019 at 7:05 AM jincheng sun 
>> > wrote:
>> >
>> >> Hi all,
>> >>
>> >> The Python Table API(without Python UDF support) has already been
>> supported
>> >> and will be available in the coming release 1.9.
>> >> As Python UDF is very important for Python users, we'd like to start
>> the
>> >> discussion about the Python UDF support in the Python Table API.
>> >> Aljoscha Krettek, Dian Fu and I have discussed offline and have
>> drafted a
>> >> design doc[1]. It includes the following items:
>> >>
>> >> - The user-defined function interfaces.
>> >> - The user-defined function execution architecture.
>> >>
>> >> As mentioned by many guys in the previous discussion thread[2], a
>> >> portability framework was introduced in Apache Beam in latest
>> releases. It
>> >> provides well-defined, language-neutral data structures and protocols
>> for
>> >> language-neutral user-defined function execution. This design is based
>> on
>> >> Beam's portability framework. We will introduce how to make use of
>> Beam's
>> >> portability framework for user-defined function execution: data
>> >> transmission, state access, checkpoint, metrics, logging, etc.
>> >>
>> >> Considering that the design relies on Beam's portability framework for
>> >> Python user-defined function execution and not all the contributors in
>> >> Flink community are familiar with Beam's portability framework, we have
>> >> done a prototype[3] for proof of concept and also ease of
>> understanding of
>> >> the design.
>> >>
>> >> Welcome any feedback.
>> >>
>> >> Best,
>> >> Jincheng
>> >>
>> >> [1]
>> >>
>> >>
>> https://docs.google.com/document/d/1WpTyCXAQh8Jr2yWfz7MWCD2-lou05QaQFb810ZvTefY/edit?usp=sharing
>> >> [2]
>> >>
>> >>
>> http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/DISCUSS-FLIP-38-Support-python-language-in-flink-TableAPI-td28061.html
>> >> [3] https://github.com/dianfu/flink/commits/udf_poc
>> >>
>>
>>

Re: [DISCUSS] Flink Python User-Defined Function for Table API

[jincheng sun]

Hi Thomas,

Thanks for your confirmation and the very important reminder about bundle
processing.

I have had add the description about how to perform bundle processing from
the perspective of checkpoint and watermark. Feel free to leave comments if
there are anything not describe clearly.

Best,
Jincheng


Dian Fu  于2019年8月14日周三 上午10:08写道：

> Hi Thomas,
>
> Thanks a lot the suggestions.
>
> Regarding to bundle processing, there is a section "Checkpoint"[1] in the
> design doc which talks about how to handle the checkpoint.
> However, I think you are right that we should talk more about it, such as
> what's bundle processing, how it affects the checkpoint and watermark, how
> to handle the checkpoint and watermark, etc.
>
> [1]
> https://docs.google.com/document/d/1WpTyCXAQh8Jr2yWfz7MWCD2-lou05QaQFb810ZvTefY/edit#heading=h.urladt565yo3
> <
> https://docs.google.com/document/d/1WpTyCXAQh8Jr2yWfz7MWCD2-lou05QaQFb810ZvTefY/edit#heading=h.urladt565yo3
> >
>
> Regards,
> Dian
>
> > 在 2019年8月14日，上午1:01，Thomas Weise  写道：
> >
> > Hi Jincheng,
> >
> > Thanks for putting this together. The proposal is very detailed, thorough
> > and for me as a Beam Flink runner contributor easy to understand :)
> >
> > One thing that you should probably detail more is the bundle processing.
> It
> > is critically important for performance that multiple elements are
> > processed in a bundle. The default bundle size in the Flink runner is 1s
> or
> > 1000 elements, whichever comes first. And for streaming, you can find the
> > logic necessary to align the bundle processing with watermarks and
> > checkpointing here:
> >
> https://github.com/apache/beam/blob/release-2.14.0/runners/flink/src/main/java/org/apache/beam/runners/flink/translation/wrappers/streaming/ExecutableStageDoFnOperator.java
> >
> > Thomas
> >
> >
> >
> >
> >
> >
> >
> > On Tue, Aug 13, 2019 at 7:05 AM jincheng sun 
> > wrote:
> >
> >> Hi all,
> >>
> >> The Python Table API(without Python UDF support) has already been
> supported
> >> and will be available in the coming release 1.9.
> >> As Python UDF is very important for Python users, we'd like to start the
> >> discussion about the Python UDF support in the Python Table API.
> >> Aljoscha Krettek, Dian Fu and I have discussed offline and have drafted
> a
> >> design doc[1]. It includes the following items:
> >>
> >> - The user-defined function interfaces.
> >> - The user-defined function execution architecture.
> >>
> >> As mentioned by many guys in the previous discussion thread[2], a
> >> portability framework was introduced in Apache Beam in latest releases.
> It
> >> provides well-defined, language-neutral data structures and protocols
> for
> >> language-neutral user-defined function execution. This design is based
> on
> >> Beam's portability framework. We will introduce how to make use of
> Beam's
> >> portability framework for user-defined function execution: data
> >> transmission, state access, checkpoint, metrics, logging, etc.
> >>
> >> Considering that the design relies on Beam's portability framework for
> >> Python user-defined function execution and not all the contributors in
> >> Flink community are familiar with Beam's portability framework, we have
> >> done a prototype[3] for proof of concept and also ease of understanding
> of
> >> the design.
> >>
> >> Welcome any feedback.
> >>
> >> Best,
> >> Jincheng
> >>
> >> [1]
> >>
> >>
> https://docs.google.com/document/d/1WpTyCXAQh8Jr2yWfz7MWCD2-lou05QaQFb810ZvTefY/edit?usp=sharing
> >> [2]
> >>
> >>
> http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/DISCUSS-FLIP-38-Support-python-language-in-flink-TableAPI-td28061.html
> >> [3] https://github.com/dianfu/flink/commits/udf_poc
> >>
>
>

Re: [DISCUSS] Flink Python User-Defined Function for Table API

[Dian Fu]

Hi Thomas,

Thanks a lot the suggestions.

Regarding to bundle processing, there is a section "Checkpoint"[1] in the 
design doc which talks about how to handle the checkpoint.
However, I think you are right that we should talk more about it, such as 
what's bundle processing, how it affects the checkpoint and watermark, how to 
handle the checkpoint and watermark, etc.

[1] 
https://docs.google.com/document/d/1WpTyCXAQh8Jr2yWfz7MWCD2-lou05QaQFb810ZvTefY/edit#heading=h.urladt565yo3
 


Regards,
Dian

> 在 2019年8月14日，上午1:01，Thomas Weise  写道：
> 
> Hi Jincheng,
> 
> Thanks for putting this together. The proposal is very detailed, thorough
> and for me as a Beam Flink runner contributor easy to understand :)
> 
> One thing that you should probably detail more is the bundle processing. It
> is critically important for performance that multiple elements are
> processed in a bundle. The default bundle size in the Flink runner is 1s or
> 1000 elements, whichever comes first. And for streaming, you can find the
> logic necessary to align the bundle processing with watermarks and
> checkpointing here:
> https://github.com/apache/beam/blob/release-2.14.0/runners/flink/src/main/java/org/apache/beam/runners/flink/translation/wrappers/streaming/ExecutableStageDoFnOperator.java
> 
> Thomas
> 
> 
> 
> 
> 
> 
> 
> On Tue, Aug 13, 2019 at 7:05 AM jincheng sun 
> wrote:
> 
>> Hi all,
>> 
>> The Python Table API(without Python UDF support) has already been supported
>> and will be available in the coming release 1.9.
>> As Python UDF is very important for Python users, we'd like to start the
>> discussion about the Python UDF support in the Python Table API.
>> Aljoscha Krettek, Dian Fu and I have discussed offline and have drafted a
>> design doc[1]. It includes the following items:
>> 
>> - The user-defined function interfaces.
>> - The user-defined function execution architecture.
>> 
>> As mentioned by many guys in the previous discussion thread[2], a
>> portability framework was introduced in Apache Beam in latest releases. It
>> provides well-defined, language-neutral data structures and protocols for
>> language-neutral user-defined function execution. This design is based on
>> Beam's portability framework. We will introduce how to make use of Beam's
>> portability framework for user-defined function execution: data
>> transmission, state access, checkpoint, metrics, logging, etc.
>> 
>> Considering that the design relies on Beam's portability framework for
>> Python user-defined function execution and not all the contributors in
>> Flink community are familiar with Beam's portability framework, we have
>> done a prototype[3] for proof of concept and also ease of understanding of
>> the design.
>> 
>> Welcome any feedback.
>> 
>> Best,
>> Jincheng
>> 
>> [1]
>> 
>> https://docs.google.com/document/d/1WpTyCXAQh8Jr2yWfz7MWCD2-lou05QaQFb810ZvTefY/edit?usp=sharing
>> [2]
>> 
>> http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/DISCUSS-FLIP-38-Support-python-language-in-flink-TableAPI-td28061.html
>> [3] https://github.com/dianfu/flink/commits/udf_poc
>> 

Re: [DISCUSS] Flink Python User-Defined Function for Table API

[Thomas Weise]

Hi Jincheng,

Thanks for putting this together. The proposal is very detailed, thorough
and for me as a Beam Flink runner contributor easy to understand :)

One thing that you should probably detail more is the bundle processing. It
is critically important for performance that multiple elements are
processed in a bundle. The default bundle size in the Flink runner is 1s or
1000 elements, whichever comes first. And for streaming, you can find the
logic necessary to align the bundle processing with watermarks and
checkpointing here:
https://github.com/apache/beam/blob/release-2.14.0/runners/flink/src/main/java/org/apache/beam/runners/flink/translation/wrappers/streaming/ExecutableStageDoFnOperator.java

Thomas







On Tue, Aug 13, 2019 at 7:05 AM jincheng sun 
wrote:

> Hi all,
>
> The Python Table API(without Python UDF support) has already been supported
> and will be available in the coming release 1.9.
> As Python UDF is very important for Python users, we'd like to start the
> discussion about the Python UDF support in the Python Table API.
> Aljoscha Krettek, Dian Fu and I have discussed offline and have drafted a
> design doc[1]. It includes the following items:
>
> - The user-defined function interfaces.
> - The user-defined function execution architecture.
>
>  As mentioned by many guys in the previous discussion thread[2], a
> portability framework was introduced in Apache Beam in latest releases. It
> provides well-defined, language-neutral data structures and protocols for
> language-neutral user-defined function execution. This design is based on
> Beam's portability framework. We will introduce how to make use of Beam's
> portability framework for user-defined function execution: data
> transmission, state access, checkpoint, metrics, logging, etc.
>
> Considering that the design relies on Beam's portability framework for
> Python user-defined function execution and not all the contributors in
> Flink community are familiar with Beam's portability framework, we have
> done a prototype[3] for proof of concept and also ease of understanding of
> the design.
>
> Welcome any feedback.
>
> Best,
> Jincheng
>
> [1]
>
> https://docs.google.com/document/d/1WpTyCXAQh8Jr2yWfz7MWCD2-lou05QaQFb810ZvTefY/edit?usp=sharing
> [2]
>
> http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/DISCUSS-FLIP-38-Support-python-language-in-flink-TableAPI-td28061.html
> [3] https://github.com/dianfu/flink/commits/udf_poc
>