[DISCUSS] Remove flink-connector-filesystem module.

[Kostas Kloudas-4]

No, I do not think that "we are fine with removing it at the cost of
friction for some users".

I believe that this can be another discussion that we should have as
soon as we establish that someone is actually using it. The point I am
trying to make is that if no user is using it, we should remove it and
not leave unmaintained code around.

On Wed, Oct 28, 2020 at 12:11 PM Chesnay Schepler <[hidden email]> wrote:

>
> The alternative could also be to use a different argument than "no one
> uses it", e.g., we are fine with removing it at the cost of friction for
> some users because there are better alternatives.
>
> On 10/28/2020 10:46 AM, Kostas Kloudas wrote:
> > I think that the mailing lists is the best we can do and I would say
> > that they seem to be working pretty well (e.g. the recent Mesos
> > discussion).
> > Of course they are not perfect but the alternative would be to never
> > remove anything user facing until the next major release, which I find
> > pretty strict.
> >
> > On Wed, Oct 28, 2020 at 10:04 AM Chesnay Schepler <[hidden email]> wrote:
> >> If the conclusion is that we shouldn't remove it if _anyone_ is using
> >> it, then we cannot remove it because the user ML obviously does not
> >> reach all users.
> >>
> >> On 10/28/2020 9:28 AM, Kostas Kloudas wrote:
> >>> Hi all,
> >>>
> >>> I am bringing the up again to see if there are any users actively
> >>> using the BucketingSink.
> >>> So far, if I am not mistaken (and really sorry if I forgot anything),
> >>> it is only a discussion between devs about the potential problems of
> >>> removing it. I totally understand Chesnay's concern about not
> >>> providing compatibility with the StreamingFileSink (SFS) and if there
> >>> are any users, then we should not remove it without trying to find a
> >>> solution for them.
> >>>
> >>> But if there are no users then I would still propose to remove the
> >>> module, given that I am not aware of any efforts to provide
> >>> compatibility with the SFS any time soon.
> >>> The reasons for removing it also include the facts that we do not
> >>> actively maintain it and we do not add new features. As for potential
> >>> missing features in the SFS compared to the BucketingSink that was
> >>> mentioned before, I am not aware of any fundamental limitations and
> >>> even if there are, I would assume that the solution is not to direct
> >>> the users to a deprecated sink but rather try to increase the
> >>> functionality of the actively maintained one.
> >>>
> >>> Please keep in mind that the BucketingSink is deprecated since FLINK
> >>> 1.9 and there is a new File Sink that is coming as part of FLIP-143
> >>> [1].
> >>> Again, if there are any active users who cannot migrate easily, then
> >>> we cannot remove it before trying to provide a smooth migration path.
> >>>
> >>> Thanks,
> >>> Kostas
> >>>
> >>> [1] https://cwiki.apache.org/confluence/display/FLINK/FLIP-143%3A+Unified+Sink+API
> >>>
> >>> On Fri, Oct 16, 2020 at 4:36 PM Chesnay Schepler <[hidden email]> wrote:
> >>>> @Seth: Earlier in this discussion it was said that the BucketingSink
> >>>> would not be usable in 1.12 .
> >>>>
> >>>> On 10/16/2020 4:25 PM, Seth Wiesman wrote:
> >>>>> +1 It has been deprecated for some time and the StreamingFileSink has
> >>>>> stabalized with a large number of formats and features.
> >>>>>
> >>>>> Plus, the bucketing sink only implements a small number of stable
> >>>>> interfaces[1]. I would expect users to continue to use the bucketing sink
> >>>>> from the 1.11 release with future versions for some time.
> >>>>>
> >>>>> Seth
> >>>>>
> >>>>> https://github.com/apache/flink/blob/2ff3b771cbb091e1f43686dd8e176cea6d435501/flink-connectors/flink-connector-filesystem/src/main/java/org/apache/flink/streaming/connectors/fs/bucketing/BucketingSink.java#L170-L172
> >>>>>
> >>>>> On Thu, Oct 15, 2020 at 2:57 PM Kostas Kloudas <[hidden email]> wrote:
> >>>>>
> >>>>>> @Arvid Heise I also do not remember exactly what were all the
> >>>>>> problems. The fact that we added some more bulk formats to the
> >>>>>> streaming file sink definitely reduced the non-supported features. In
> >>>>>> addition, the latest discussion I found on the topic was [1] and the
> >>>>>> conclusion of that discussion seems to be to remove it.
> >>>>>>
> >>>>>> Currently, I cannot find any obvious reason why keeping the
> >>>>>> BucketingSink, apart from the fact that we do not have a migration
> >>>>>> plan unfortunately. This is why I posted this to dev@ and user@.
> >>>>>>
> >>>>>> Cheers,
> >>>>>> Kostas
> >>>>>>
> >>>>>> [1]
> >>>>>> https://lists.apache.org/thread.html/r799be74658bc7e169238cc8c1e479e961a9e85ccea19089290940ff0%40%3Cdev.flink.apache.org%3E
> >>>>>>
> >>>>>> On Wed, Oct 14, 2020 at 8:03 AM Arvid Heise <[hidden email]> wrote:
> >>>>>>> I remember this conversation popping up a few times already and I'm in
> >>>>>>> general a big fan of removing BucketingSink.
> >>>>>>>
> >>>>>>> However, until now there were a few features lacking in StreamingFileSink
> >>>>>>> that are present in BucketingSink and that are being actively used (I
> >>>>>> can't
> >>>>>>> exactly remember them now, but I can look it up if everyone else is also
> >>>>>>> suffering from bad memory). Did we manage to add them in the meantime? If
> >>>>>>> not, then it feels rushed to remove it at this point.
> >>>>>>>
> >>>>>>> On Tue, Oct 13, 2020 at 2:33 PM Kostas Kloudas <[hidden email]>
> >>>>>> wrote:
> >>>>>>>> @Chesnay Schepler  Off the top of my head, I cannot find an easy way
> >>>>>>>> to migrate from the BucketingSink to the StreamingFileSink. It may be
> >>>>>>>> possible but it will require some effort because the logic would be
> >>>>>>>> "read the old state, commit it, and start fresh with the
> >>>>>>>> StreamingFileSink."
> >>>>>>>>
> >>>>>>>> On Tue, Oct 13, 2020 at 2:09 PM Aljoscha Krettek <[hidden email]>
> >>>>>>>> wrote:
> >>>>>>>>> On 13.10.20 14:01, David Anderson wrote:
> >>>>>>>>>> I thought this was waiting on FLIP-46 -- Graceful Shutdown
> >>>>>> Handling --
> >>>>>>>> and
> >>>>>>>>>> in fact, the StreamingFileSink is mentioned in that FLIP as a
> >>>>>>>> motivating
> >>>>>>>>>> use case.
> >>>>>>>>> Ah yes, I see FLIP-147 as a more general replacement for FLIP-46.
> >>>>>> Thanks
> >>>>>>>>> for the reminder, we should close FLIP-46 now with an explanatory
> >>>>>>>>> message to avoid confusion.
> >>>>>>> --
> >>>>>>>
> >>>>>>> Arvid Heise | Senior Java Developer
> >>>>>>>
> >>>>>>> <https://www.ververica.com/>
> >>>>>>>
> >>>>>>> Follow us @VervericaData
> >>>>>>>
> >>>>>>> --
> >>>>>>>
> >>>>>>> Join Flink Forward <https://flink-forward.org/> - The Apache Flink
> >>>>>>> Conference
> >>>>>>>
> >>>>>>> Stream Processing | Event Driven | Real Time
> >>>>>>>
> >>>>>>> --
> >>>>>>>
> >>>>>>> Ververica GmbH | Invalidenstrasse 115, 10115 Berlin, Germany
> >>>>>>>
> >>>>>>> --
> >>>>>>> Ververica GmbH
> >>>>>>> Registered at Amtsgericht Charlottenburg: HRB 158244 B
> >>>>>>> Managing Directors: Timothy Alexander Steinert, Yip Park Tung Jason, Ji
> >>>>>>> (Toni) Cheng
>
>

[Chesnay Schepler-3]

Then we can't remove it, because there is no way for us to ascertain
whether anyone is still using it.

Sure, the user ML is the best we got, but you can't argue that we don't
want any users to be affected and then use an imperfect mean to find users.
If you are fine with relying on the user ML, then you _are_ fine with
removing it at the cost of friction for some users.

To be clear, I, personally, don't have a problem with removing it (we
have removed other connectors in the past that did not have a migration
plan), I just reject he argumentation.

On 10/28/2020 12:21 PM, Kostas Kloudas wrote:

> No, I do not think that "we are fine with removing it at the cost of
> friction for some users".
>
> I believe that this can be another discussion that we should have as
> soon as we establish that someone is actually using it. The point I am
> trying to make is that if no user is using it, we should remove it and
> not leave unmaintained code around.
>
> On Wed, Oct 28, 2020 at 12:11 PM Chesnay Schepler <[hidden email]> wrote:
>> The alternative could also be to use a different argument than "no one
>> uses it", e.g., we are fine with removing it at the cost of friction for
>> some users because there are better alternatives.
>>
>> On 10/28/2020 10:46 AM, Kostas Kloudas wrote:
>>> I think that the mailing lists is the best we can do and I would say
>>> that they seem to be working pretty well (e.g. the recent Mesos
>>> discussion).
>>> Of course they are not perfect but the alternative would be to never
>>> remove anything user facing until the next major release, which I find
>>> pretty strict.
>>>
>>> On Wed, Oct 28, 2020 at 10:04 AM Chesnay Schepler <[hidden email]> wrote:
>>>> If the conclusion is that we shouldn't remove it if _anyone_ is using
>>>> it, then we cannot remove it because the user ML obviously does not
>>>> reach all users.
>>>>
>>>> On 10/28/2020 9:28 AM, Kostas Kloudas wrote:
>>>>> Hi all,
>>>>>
>>>>> I am bringing the up again to see if there are any users actively
>>>>> using the BucketingSink.
>>>>> So far, if I am not mistaken (and really sorry if I forgot anything),
>>>>> it is only a discussion between devs about the potential problems of
>>>>> removing it. I totally understand Chesnay's concern about not
>>>>> providing compatibility with the StreamingFileSink (SFS) and if there
>>>>> are any users, then we should not remove it without trying to find a
>>>>> solution for them.
>>>>>
>>>>> But if there are no users then I would still propose to remove the
>>>>> module, given that I am not aware of any efforts to provide
>>>>> compatibility with the SFS any time soon.
>>>>> The reasons for removing it also include the facts that we do not
>>>>> actively maintain it and we do not add new features. As for potential
>>>>> missing features in the SFS compared to the BucketingSink that was
>>>>> mentioned before, I am not aware of any fundamental limitations and
>>>>> even if there are, I would assume that the solution is not to direct
>>>>> the users to a deprecated sink but rather try to increase the
>>>>> functionality of the actively maintained one.
>>>>>
>>>>> Please keep in mind that the BucketingSink is deprecated since FLINK
>>>>> 1.9 and there is a new File Sink that is coming as part of FLIP-143
>>>>> [1].
>>>>> Again, if there are any active users who cannot migrate easily, then
>>>>> we cannot remove it before trying to provide a smooth migration path.
>>>>>
>>>>> Thanks,
>>>>> Kostas
>>>>>
>>>>> [1] https://cwiki.apache.org/confluence/display/FLINK/FLIP-143%3A+Unified+Sink+API
>>>>>
>>>>> On Fri, Oct 16, 2020 at 4:36 PM Chesnay Schepler <[hidden email]> wrote:
>>>>>> @Seth: Earlier in this discussion it was said that the BucketingSink
>>>>>> would not be usable in 1.12 .
>>>>>>
>>>>>> On 10/16/2020 4:25 PM, Seth Wiesman wrote:
>>>>>>> +1 It has been deprecated for some time and the StreamingFileSink has
>>>>>>> stabalized with a large number of formats and features.
>>>>>>>
>>>>>>> Plus, the bucketing sink only implements a small number of stable
>>>>>>> interfaces[1]. I would expect users to continue to use the bucketing sink
>>>>>>> from the 1.11 release with future versions for some time.
>>>>>>>
>>>>>>> Seth
>>>>>>>
>>>>>>> https://github.com/apache/flink/blob/2ff3b771cbb091e1f43686dd8e176cea6d435501/flink-connectors/flink-connector-filesystem/src/main/java/org/apache/flink/streaming/connectors/fs/bucketing/BucketingSink.java#L170-L172
>>>>>>>
>>>>>>> On Thu, Oct 15, 2020 at 2:57 PM Kostas Kloudas <[hidden email]> wrote:
>>>>>>>
>>>>>>>> @Arvid Heise I also do not remember exactly what were all the
>>>>>>>> problems. The fact that we added some more bulk formats to the
>>>>>>>> streaming file sink definitely reduced the non-supported features. In
>>>>>>>> addition, the latest discussion I found on the topic was [1] and the
>>>>>>>> conclusion of that discussion seems to be to remove it.
>>>>>>>>
>>>>>>>> Currently, I cannot find any obvious reason why keeping the
>>>>>>>> BucketingSink, apart from the fact that we do not have a migration
>>>>>>>> plan unfortunately. This is why I posted this to dev@ and user@.
>>>>>>>>
>>>>>>>> Cheers,
>>>>>>>> Kostas
>>>>>>>>
>>>>>>>> [1]
>>>>>>>> https://lists.apache.org/thread.html/r799be74658bc7e169238cc8c1e479e961a9e85ccea19089290940ff0%40%3Cdev.flink.apache.org%3E
>>>>>>>>
>>>>>>>> On Wed, Oct 14, 2020 at 8:03 AM Arvid Heise <[hidden email]> wrote:
>>>>>>>>> I remember this conversation popping up a few times already and I'm in
>>>>>>>>> general a big fan of removing BucketingSink.
>>>>>>>>>
>>>>>>>>> However, until now there were a few features lacking in StreamingFileSink
>>>>>>>>> that are present in BucketingSink and that are being actively used (I
>>>>>>>> can't
>>>>>>>>> exactly remember them now, but I can look it up if everyone else is also
>>>>>>>>> suffering from bad memory). Did we manage to add them in the meantime? If
>>>>>>>>> not, then it feels rushed to remove it at this point.
>>>>>>>>>
>>>>>>>>> On Tue, Oct 13, 2020 at 2:33 PM Kostas Kloudas <[hidden email]>
>>>>>>>> wrote:
>>>>>>>>>> @Chesnay Schepler  Off the top of my head, I cannot find an easy way
>>>>>>>>>> to migrate from the BucketingSink to the StreamingFileSink. It may be
>>>>>>>>>> possible but it will require some effort because the logic would be
>>>>>>>>>> "read the old state, commit it, and start fresh with the
>>>>>>>>>> StreamingFileSink."
>>>>>>>>>>
>>>>>>>>>> On Tue, Oct 13, 2020 at 2:09 PM Aljoscha Krettek <[hidden email]>
>>>>>>>>>> wrote:
>>>>>>>>>>> On 13.10.20 14:01, David Anderson wrote:
>>>>>>>>>>>> I thought this was waiting on FLIP-46 -- Graceful Shutdown
>>>>>>>> Handling --
>>>>>>>>>> and
>>>>>>>>>>>> in fact, the StreamingFileSink is mentioned in that FLIP as a
>>>>>>>>>> motivating
>>>>>>>>>>>> use case.
>>>>>>>>>>> Ah yes, I see FLIP-147 as a more general replacement for FLIP-46.
>>>>>>>> Thanks
>>>>>>>>>>> for the reminder, we should close FLIP-46 now with an explanatory
>>>>>>>>>>> message to avoid confusion.
>>>>>>>>> --
>>>>>>>>>
>>>>>>>>> Arvid Heise | Senior Java Developer
>>>>>>>>>
>>>>>>>>> <https://www.ververica.com/>
>>>>>>>>>
>>>>>>>>> Follow us @VervericaData
>>>>>>>>>
>>>>>>>>> --
>>>>>>>>>
>>>>>>>>> Join Flink Forward <https://flink-forward.org/> - The Apache Flink
>>>>>>>>> Conference
>>>>>>>>>
>>>>>>>>> Stream Processing | Event Driven | Real Time
>>>>>>>>>
>>>>>>>>> --
>>>>>>>>>
>>>>>>>>> Ververica GmbH | Invalidenstrasse 115, 10115 Berlin, Germany
>>>>>>>>>
>>>>>>>>> --
>>>>>>>>> Ververica GmbH
>>>>>>>>> Registered at Amtsgericht Charlottenburg: HRB 158244 B
>>>>>>>>> Managing Directors: Timothy Alexander Steinert, Yip Park Tung Jason, Ji
>>>>>>>>> (Toni) Cheng
>>

[Stephan Ewen]

+1 to remove the Bucketing Sink.

It has been very common in the past to remove code that was deprecated for
multiple releases in favor of reducing baggage.
Also in cases that had no perfect drop-in replacement, but needed users to
forward fit the code.
I am not sure I understand why this case is so different.

Why the Bucketing Sink should be thrown out, in my opinion:

The Bucketing sink makes it easier for users to add general Hadoop writes.
But the price is that it easily leads to dataloss, because it assumes
flush()/sync() work reliably on Hadoop relicably, which they don't (HDFS
works somewhat, S3 works not at all).
I think the Bucketing sink is a trap for users, that's why it was
deprecated long ago.

The StreamingFileSink covers the majority of cases from the Bucketing Sink.
It does have some friction when adding/wrapping some general Hadoop
writers. Parts will be solved with the transactional sink work.
If something is missing and blocking users, we can prioritize adding it to
the Streaming File Sink. Also that is something we did before and it helped
being pragmatic with moving forward, rather than being held back by "maybe
there is something we don't know".




On Wed, Oct 28, 2020 at 12:36 PM Chesnay Schepler <[hidden email]>
wrote:

> Then we can't remove it, because there is no way for us to ascertain
> whether anyone is still using it.
>
> Sure, the user ML is the best we got, but you can't argue that we don't
> want any users to be affected and then use an imperfect mean to find users.
> If you are fine with relying on the user ML, then you _are_ fine with
> removing it at the cost of friction for some users.
>
> To be clear, I, personally, don't have a problem with removing it (we
> have removed other connectors in the past that did not have a migration
> plan), I just reject he argumentation.
>
> On 10/28/2020 12:21 PM, Kostas Kloudas wrote:
> > No, I do not think that "we are fine with removing it at the cost of
> > friction for some users".
> >
> > I believe that this can be another discussion that we should have as
> > soon as we establish that someone is actually using it. The point I am
> > trying to make is that if no user is using it, we should remove it and
> > not leave unmaintained code around.
> >
> > On Wed, Oct 28, 2020 at 12:11 PM Chesnay Schepler <[hidden email]>
> wrote:
> >> The alternative could also be to use a different argument than "no one
> >> uses it", e.g., we are fine with removing it at the cost of friction for
> >> some users because there are better alternatives.
> >>
> >> On 10/28/2020 10:46 AM, Kostas Kloudas wrote:
> >>> I think that the mailing lists is the best we can do and I would say
> >>> that they seem to be working pretty well (e.g. the recent Mesos
> >>> discussion).
> >>> Of course they are not perfect but the alternative would be to never
> >>> remove anything user facing until the next major release, which I find
> >>> pretty strict.
> >>>
> >>> On Wed, Oct 28, 2020 at 10:04 AM Chesnay Schepler <[hidden email]>
> wrote:
> >>>> If the conclusion is that we shouldn't remove it if _anyone_ is using
> >>>> it, then we cannot remove it because the user ML obviously does not
> >>>> reach all users.
> >>>>
> >>>> On 10/28/2020 9:28 AM, Kostas Kloudas wrote:
> >>>>> Hi all,
> >>>>>
> >>>>> I am bringing the up again to see if there are any users actively
> >>>>> using the BucketingSink.
> >>>>> So far, if I am not mistaken (and really sorry if I forgot anything),
> >>>>> it is only a discussion between devs about the potential problems of
> >>>>> removing it. I totally understand Chesnay's concern about not
> >>>>> providing compatibility with the StreamingFileSink (SFS) and if there
> >>>>> are any users, then we should not remove it without trying to find a
> >>>>> solution for them.
> >>>>>
> >>>>> But if there are no users then I would still propose to remove the
> >>>>> module, given that I am not aware of any efforts to provide
> >>>>> compatibility with the SFS any time soon.
> >>>>> The reasons for removing it also include the facts that we do not
> >>>>> actively maintain it and we do not add new features. As for potential
> >>>>> missing features in the SFS compared to the BucketingSink that was
> >>>>> mentioned before, I am not aware of any fundamental limitations and
> >>>>> even if there are, I would assume that the solution is not to direct
> >>>>> the users to a deprecated sink but rather try to increase the
> >>>>> functionality of the actively maintained one.
> >>>>>
> >>>>> Please keep in mind that the BucketingSink is deprecated since FLINK
> >>>>> 1.9 and there is a new File Sink that is coming as part of FLIP-143
> >>>>> [1].
> >>>>> Again, if there are any active users who cannot migrate easily, then
> >>>>> we cannot remove it before trying to provide a smooth migration path.
> >>>>>
> >>>>> Thanks,
> >>>>> Kostas
> >>>>>
> >>>>> [1]
> https://cwiki.apache.org/confluence/display/FLINK/FLIP-143%3A+Unified+Sink+API
> >>>>>
> >>>>> On Fri, Oct 16, 2020 at 4:36 PM Chesnay Schepler <[hidden email]>
> wrote:
> >>>>>> @Seth: Earlier in this discussion it was said that the BucketingSink
> >>>>>> would not be usable in 1.12 .
> >>>>>>
> >>>>>> On 10/16/2020 4:25 PM, Seth Wiesman wrote:
> >>>>>>> +1 It has been deprecated for some time and the StreamingFileSink
> has
> >>>>>>> stabalized with a large number of formats and features.
> >>>>>>>
> >>>>>>> Plus, the bucketing sink only implements a small number of stable
> >>>>>>> interfaces[1]. I would expect users to continue to use the
> bucketing sink
> >>>>>>> from the 1.11 release with future versions for some time.
> >>>>>>>
> >>>>>>> Seth
> >>>>>>>
> >>>>>>>
> https://github.com/apache/flink/blob/2ff3b771cbb091e1f43686dd8e176cea6d435501/flink-connectors/flink-connector-filesystem/src/main/java/org/apache/flink/streaming/connectors/fs/bucketing/BucketingSink.java#L170-L172
> >>>>>>>
> >>>>>>> On Thu, Oct 15, 2020 at 2:57 PM Kostas Kloudas <[hidden email]>
> wrote:
> >>>>>>>
> >>>>>>>> @Arvid Heise I also do not remember exactly what were all the
> >>>>>>>> problems. The fact that we added some more bulk formats to the
> >>>>>>>> streaming file sink definitely reduced the non-supported
> features. In
> >>>>>>>> addition, the latest discussion I found on the topic was [1] and
> the
> >>>>>>>> conclusion of that discussion seems to be to remove it.
> >>>>>>>>
> >>>>>>>> Currently, I cannot find any obvious reason why keeping the
> >>>>>>>> BucketingSink, apart from the fact that we do not have a migration
> >>>>>>>> plan unfortunately. This is why I posted this to dev@ and user@.
> >>>>>>>>
> >>>>>>>> Cheers,
> >>>>>>>> Kostas
> >>>>>>>>
> >>>>>>>> [1]
> >>>>>>>>
> https://lists.apache.org/thread.html/r799be74658bc7e169238cc8c1e479e961a9e85ccea19089290940ff0%40%3Cdev.flink.apache.org%3E
> >>>>>>>>
> >>>>>>>> On Wed, Oct 14, 2020 at 8:03 AM Arvid Heise <[hidden email]>
> wrote:
> >>>>>>>>> I remember this conversation popping up a few times already and
> I'm in
> >>>>>>>>> general a big fan of removing BucketingSink.
> >>>>>>>>>
> >>>>>>>>> However, until now there were a few features lacking in
> StreamingFileSink
> >>>>>>>>> that are present in BucketingSink and that are being actively
> used (I
> >>>>>>>> can't
> >>>>>>>>> exactly remember them now, but I can look it up if everyone else
> is also
> >>>>>>>>> suffering from bad memory). Did we manage to add them in the
> meantime? If
> >>>>>>>>> not, then it feels rushed to remove it at this point.
> >>>>>>>>>
> >>>>>>>>> On Tue, Oct 13, 2020 at 2:33 PM Kostas Kloudas <
> [hidden email]>
> >>>>>>>> wrote:
> >>>>>>>>>> @Chesnay Schepler  Off the top of my head, I cannot find an
> easy way
> >>>>>>>>>> to migrate from the BucketingSink to the StreamingFileSink. It
> may be
> >>>>>>>>>> possible but it will require some effort because the logic
> would be
> >>>>>>>>>> "read the old state, commit it, and start fresh with the
> >>>>>>>>>> StreamingFileSink."
> >>>>>>>>>>
> >>>>>>>>>> On Tue, Oct 13, 2020 at 2:09 PM Aljoscha Krettek <
> [hidden email]>
> >>>>>>>>>> wrote:
> >>>>>>>>>>> On 13.10.20 14:01, David Anderson wrote:
> >>>>>>>>>>>> I thought this was waiting on FLIP-46 -- Graceful Shutdown
> >>>>>>>> Handling --
> >>>>>>>>>> and
> >>>>>>>>>>>> in fact, the StreamingFileSink is mentioned in that FLIP as a
> >>>>>>>>>> motivating
> >>>>>>>>>>>> use case.
> >>>>>>>>>>> Ah yes, I see FLIP-147 as a more general replacement for
> FLIP-46.
> >>>>>>>> Thanks
> >>>>>>>>>>> for the reminder, we should close FLIP-46 now with an
> explanatory
> >>>>>>>>>>> message to avoid confusion.
> >>>>>>>>> --
> >>>>>>>>>
> >>>>>>>>> Arvid Heise | Senior Java Developer
> >>>>>>>>>
> >>>>>>>>> <https://www.ververica.com/>
> >>>>>>>>>
> >>>>>>>>> Follow us @VervericaData
> >>>>>>>>>
> >>>>>>>>> --
> >>>>>>>>>
> >>>>>>>>> Join Flink Forward <https://flink-forward.org/> - The Apache
> Flink
> >>>>>>>>> Conference
> >>>>>>>>>
> >>>>>>>>> Stream Processing | Event Driven | Real Time
> >>>>>>>>>
> >>>>>>>>> --
> >>>>>>>>>
> >>>>>>>>> Ververica GmbH | Invalidenstrasse 115, 10115 Berlin, Germany
> >>>>>>>>>
> >>>>>>>>> --
> >>>>>>>>> Ververica GmbH
> >>>>>>>>> Registered at Amtsgericht Charlottenburg: HRB 158244 B
> >>>>>>>>> Managing Directors: Timothy Alexander Steinert, Yip Park Tung
> Jason, Ji
> >>>>>>>>> (Toni) Cheng
> >>
>
>

[Kostas Kloudas-4]

Thanks for the discussion!

From this thread I do not see any objection with moving forward with
removing the sink.
Given this I will open a voting thread tomorrow.

Cheers,
Kostas

On Wed, Oct 28, 2020 at 6:50 PM Stephan Ewen <[hidden email]> wrote:

>
> +1 to remove the Bucketing Sink.
>
> It has been very common in the past to remove code that was deprecated for multiple releases in favor of reducing baggage.
> Also in cases that had no perfect drop-in replacement, but needed users to forward fit the code.
> I am not sure I understand why this case is so different.
>
> Why the Bucketing Sink should be thrown out, in my opinion:
>
> The Bucketing sink makes it easier for users to add general Hadoop writes.
> But the price is that it easily leads to dataloss, because it assumes flush()/sync() work reliably on Hadoop relicably, which they don't (HDFS works somewhat, S3 works not at all).
> I think the Bucketing sink is a trap for users, that's why it was deprecated long ago.
>
> The StreamingFileSink covers the majority of cases from the Bucketing Sink.
> It does have some friction when adding/wrapping some general Hadoop writers. Parts will be solved with the transactional sink work.
> If something is missing and blocking users, we can prioritize adding it to the Streaming File Sink. Also that is something we did before and it helped being pragmatic with moving forward, rather than being held back by "maybe there is something we don't know".
>
>
>
>
> On Wed, Oct 28, 2020 at 12:36 PM Chesnay Schepler <[hidden email]> wrote:
>>
>> Then we can't remove it, because there is no way for us to ascertain
>> whether anyone is still using it.
>>
>> Sure, the user ML is the best we got, but you can't argue that we don't
>> want any users to be affected and then use an imperfect mean to find users.
>> If you are fine with relying on the user ML, then you _are_ fine with
>> removing it at the cost of friction for some users.
>>
>> To be clear, I, personally, don't have a problem with removing it (we
>> have removed other connectors in the past that did not have a migration
>> plan), I just reject he argumentation.
>>
>> On 10/28/2020 12:21 PM, Kostas Kloudas wrote:
>> > No, I do not think that "we are fine with removing it at the cost of
>> > friction for some users".
>> >
>> > I believe that this can be another discussion that we should have as
>> > soon as we establish that someone is actually using it. The point I am
>> > trying to make is that if no user is using it, we should remove it and
>> > not leave unmaintained code around.
>> >
>> > On Wed, Oct 28, 2020 at 12:11 PM Chesnay Schepler <[hidden email]> wrote:
>> >> The alternative could also be to use a different argument than "no one
>> >> uses it", e.g., we are fine with removing it at the cost of friction for
>> >> some users because there are better alternatives.
>> >>
>> >> On 10/28/2020 10:46 AM, Kostas Kloudas wrote:
>> >>> I think that the mailing lists is the best we can do and I would say
>> >>> that they seem to be working pretty well (e.g. the recent Mesos
>> >>> discussion).
>> >>> Of course they are not perfect but the alternative would be to never
>> >>> remove anything user facing until the next major release, which I find
>> >>> pretty strict.
>> >>>
>> >>> On Wed, Oct 28, 2020 at 10:04 AM Chesnay Schepler <[hidden email]> wrote:
>> >>>> If the conclusion is that we shouldn't remove it if _anyone_ is using
>> >>>> it, then we cannot remove it because the user ML obviously does not
>> >>>> reach all users.
>> >>>>
>> >>>> On 10/28/2020 9:28 AM, Kostas Kloudas wrote:
>> >>>>> Hi all,
>> >>>>>
>> >>>>> I am bringing the up again to see if there are any users actively
>> >>>>> using the BucketingSink.
>> >>>>> So far, if I am not mistaken (and really sorry if I forgot anything),
>> >>>>> it is only a discussion between devs about the potential problems of
>> >>>>> removing it. I totally understand Chesnay's concern about not
>> >>>>> providing compatibility with the StreamingFileSink (SFS) and if there
>> >>>>> are any users, then we should not remove it without trying to find a
>> >>>>> solution for them.
>> >>>>>
>> >>>>> But if there are no users then I would still propose to remove the
>> >>>>> module, given that I am not aware of any efforts to provide
>> >>>>> compatibility with the SFS any time soon.
>> >>>>> The reasons for removing it also include the facts that we do not
>> >>>>> actively maintain it and we do not add new features. As for potential
>> >>>>> missing features in the SFS compared to the BucketingSink that was
>> >>>>> mentioned before, I am not aware of any fundamental limitations and
>> >>>>> even if there are, I would assume that the solution is not to direct
>> >>>>> the users to a deprecated sink but rather try to increase the
>> >>>>> functionality of the actively maintained one.
>> >>>>>
>> >>>>> Please keep in mind that the BucketingSink is deprecated since FLINK
>> >>>>> 1.9 and there is a new File Sink that is coming as part of FLIP-143
>> >>>>> [1].
>> >>>>> Again, if there are any active users who cannot migrate easily, then
>> >>>>> we cannot remove it before trying to provide a smooth migration path.
>> >>>>>
>> >>>>> Thanks,
>> >>>>> Kostas
>> >>>>>
>> >>>>> [1] https://cwiki.apache.org/confluence/display/FLINK/FLIP-143%3A+Unified+Sink+API
>> >>>>>
>> >>>>> On Fri, Oct 16, 2020 at 4:36 PM Chesnay Schepler <[hidden email]> wrote:
>> >>>>>> @Seth: Earlier in this discussion it was said that the BucketingSink
>> >>>>>> would not be usable in 1.12 .
>> >>>>>>
>> >>>>>> On 10/16/2020 4:25 PM, Seth Wiesman wrote:
>> >>>>>>> +1 It has been deprecated for some time and the StreamingFileSink has
>> >>>>>>> stabalized with a large number of formats and features.
>> >>>>>>>
>> >>>>>>> Plus, the bucketing sink only implements a small number of stable
>> >>>>>>> interfaces[1]. I would expect users to continue to use the bucketing sink
>> >>>>>>> from the 1.11 release with future versions for some time.
>> >>>>>>>
>> >>>>>>> Seth
>> >>>>>>>
>> >>>>>>> https://github.com/apache/flink/blob/2ff3b771cbb091e1f43686dd8e176cea6d435501/flink-connectors/flink-connector-filesystem/src/main/java/org/apache/flink/streaming/connectors/fs/bucketing/BucketingSink.java#L170-L172
>> >>>>>>>
>> >>>>>>> On Thu, Oct 15, 2020 at 2:57 PM Kostas Kloudas <[hidden email]> wrote:
>> >>>>>>>
>> >>>>>>>> @Arvid Heise I also do not remember exactly what were all the
>> >>>>>>>> problems. The fact that we added some more bulk formats to the
>> >>>>>>>> streaming file sink definitely reduced the non-supported features. In
>> >>>>>>>> addition, the latest discussion I found on the topic was [1] and the
>> >>>>>>>> conclusion of that discussion seems to be to remove it.
>> >>>>>>>>
>> >>>>>>>> Currently, I cannot find any obvious reason why keeping the
>> >>>>>>>> BucketingSink, apart from the fact that we do not have a migration
>> >>>>>>>> plan unfortunately. This is why I posted this to dev@ and user@.
>> >>>>>>>>
>> >>>>>>>> Cheers,
>> >>>>>>>> Kostas
>> >>>>>>>>
>> >>>>>>>> [1]
>> >>>>>>>> https://lists.apache.org/thread.html/r799be74658bc7e169238cc8c1e479e961a9e85ccea19089290940ff0%40%3Cdev.flink.apache.org%3E
>> >>>>>>>>
>> >>>>>>>> On Wed, Oct 14, 2020 at 8:03 AM Arvid Heise <[hidden email]> wrote:
>> >>>>>>>>> I remember this conversation popping up a few times already and I'm in
>> >>>>>>>>> general a big fan of removing BucketingSink.
>> >>>>>>>>>
>> >>>>>>>>> However, until now there were a few features lacking in StreamingFileSink
>> >>>>>>>>> that are present in BucketingSink and that are being actively used (I
>> >>>>>>>> can't
>> >>>>>>>>> exactly remember them now, but I can look it up if everyone else is also
>> >>>>>>>>> suffering from bad memory). Did we manage to add them in the meantime? If
>> >>>>>>>>> not, then it feels rushed to remove it at this point.
>> >>>>>>>>>
>> >>>>>>>>> On Tue, Oct 13, 2020 at 2:33 PM Kostas Kloudas <[hidden email]>
>> >>>>>>>> wrote:
>> >>>>>>>>>> @Chesnay Schepler  Off the top of my head, I cannot find an easy way
>> >>>>>>>>>> to migrate from the BucketingSink to the StreamingFileSink. It may be
>> >>>>>>>>>> possible but it will require some effort because the logic would be
>> >>>>>>>>>> "read the old state, commit it, and start fresh with the
>> >>>>>>>>>> StreamingFileSink."
>> >>>>>>>>>>
>> >>>>>>>>>> On Tue, Oct 13, 2020 at 2:09 PM Aljoscha Krettek <[hidden email]>
>> >>>>>>>>>> wrote:
>> >>>>>>>>>>> On 13.10.20 14:01, David Anderson wrote:
>> >>>>>>>>>>>> I thought this was waiting on FLIP-46 -- Graceful Shutdown
>> >>>>>>>> Handling --
>> >>>>>>>>>> and
>> >>>>>>>>>>>> in fact, the StreamingFileSink is mentioned in that FLIP as a
>> >>>>>>>>>> motivating
>> >>>>>>>>>>>> use case.
>> >>>>>>>>>>> Ah yes, I see FLIP-147 as a more general replacement for FLIP-46.
>> >>>>>>>> Thanks
>> >>>>>>>>>>> for the reminder, we should close FLIP-46 now with an explanatory
>> >>>>>>>>>>> message to avoid confusion.
>> >>>>>>>>> --
>> >>>>>>>>>
>> >>>>>>>>> Arvid Heise | Senior Java Developer
>> >>>>>>>>>
>> >>>>>>>>> <https://www.ververica.com/>
>> >>>>>>>>>
>> >>>>>>>>> Follow us @VervericaData
>> >>>>>>>>>
>> >>>>>>>>> --
>> >>>>>>>>>
>> >>>>>>>>> Join Flink Forward <https://flink-forward.org/> - The Apache Flink
>> >>>>>>>>> Conference
>> >>>>>>>>>
>> >>>>>>>>> Stream Processing | Event Driven | Real Time
>> >>>>>>>>>
>> >>>>>>>>> --
>> >>>>>>>>>
>> >>>>>>>>> Ververica GmbH | Invalidenstrasse 115, 10115 Berlin, Germany
>> >>>>>>>>>
>> >>>>>>>>> --
>> >>>>>>>>> Ververica GmbH
>> >>>>>>>>> Registered at Amtsgericht Charlottenburg: HRB 158244 B
>> >>>>>>>>> Managing Directors: Timothy Alexander Steinert, Yip Park Tung Jason, Ji
>> >>>>>>>>> (Toni) Cheng
>> >>
>>

[Jingsong Li]

+1 to remove the Bucketing Sink.

Thanks for the effort on ORC and `HadoopPathBasedBulkFormatBuilder`, I
think it's safe to get rid of the old Bucketing API with them.

Best,
Jingsong

On Thu, Oct 29, 2020 at 3:06 AM Kostas Kloudas <[hidden email]> wrote:

> Thanks for the discussion!
>
> From this thread I do not see any objection with moving forward with
> removing the sink.
> Given this I will open a voting thread tomorrow.
>
> Cheers,
> Kostas
>
> On Wed, Oct 28, 2020 at 6:50 PM Stephan Ewen <[hidden email]> wrote:
> >
> > +1 to remove the Bucketing Sink.
> >
> > It has been very common in the past to remove code that was deprecated
> for multiple releases in favor of reducing baggage.
> > Also in cases that had no perfect drop-in replacement, but needed users
> to forward fit the code.
> > I am not sure I understand why this case is so different.
> >
> > Why the Bucketing Sink should be thrown out, in my opinion:
> >
> > The Bucketing sink makes it easier for users to add general Hadoop
> writes.
> > But the price is that it easily leads to dataloss, because it assumes
> flush()/sync() work reliably on Hadoop relicably, which they don't (HDFS
> works somewhat, S3 works not at all).
> > I think the Bucketing sink is a trap for users, that's why it was
> deprecated long ago.
> >
> > The StreamingFileSink covers the majority of cases from the Bucketing
> Sink.
> > It does have some friction when adding/wrapping some general Hadoop
> writers. Parts will be solved with the transactional sink work.
> > If something is missing and blocking users, we can prioritize adding it
> to the Streaming File Sink. Also that is something we did before and it
> helped being pragmatic with moving forward, rather than being held back by
> "maybe there is something we don't know".
> >
> >
> >
> >
> > On Wed, Oct 28, 2020 at 12:36 PM Chesnay Schepler <[hidden email]>
> wrote:
> >>
> >> Then we can't remove it, because there is no way for us to ascertain
> >> whether anyone is still using it.
> >>
> >> Sure, the user ML is the best we got, but you can't argue that we don't
> >> want any users to be affected and then use an imperfect mean to find
> users.
> >> If you are fine with relying on the user ML, then you _are_ fine with
> >> removing it at the cost of friction for some users.
> >>
> >> To be clear, I, personally, don't have a problem with removing it (we
> >> have removed other connectors in the past that did not have a migration
> >> plan), I just reject he argumentation.
> >>
> >> On 10/28/2020 12:21 PM, Kostas Kloudas wrote:
> >> > No, I do not think that "we are fine with removing it at the cost of
> >> > friction for some users".
> >> >
> >> > I believe that this can be another discussion that we should have as
> >> > soon as we establish that someone is actually using it. The point I am
> >> > trying to make is that if no user is using it, we should remove it and
> >> > not leave unmaintained code around.
> >> >
> >> > On Wed, Oct 28, 2020 at 12:11 PM Chesnay Schepler <[hidden email]>
> wrote:
> >> >> The alternative could also be to use a different argument than "no
> one
> >> >> uses it", e.g., we are fine with removing it at the cost of friction
> for
> >> >> some users because there are better alternatives.
> >> >>
> >> >> On 10/28/2020 10:46 AM, Kostas Kloudas wrote:
> >> >>> I think that the mailing lists is the best we can do and I would say
> >> >>> that they seem to be working pretty well (e.g. the recent Mesos
> >> >>> discussion).
> >> >>> Of course they are not perfect but the alternative would be to never
> >> >>> remove anything user facing until the next major release, which I
> find
> >> >>> pretty strict.
> >> >>>
> >> >>> On Wed, Oct 28, 2020 at 10:04 AM Chesnay Schepler <
> [hidden email]> wrote:
> >> >>>> If the conclusion is that we shouldn't remove it if _anyone_ is
> using
> >> >>>> it, then we cannot remove it because the user ML obviously does not
> >> >>>> reach all users.
> >> >>>>
> >> >>>> On 10/28/2020 9:28 AM, Kostas Kloudas wrote:
> >> >>>>> Hi all,
> >> >>>>>
> >> >>>>> I am bringing the up again to see if there are any users actively
> >> >>>>> using the BucketingSink.
> >> >>>>> So far, if I am not mistaken (and really sorry if I forgot
> anything),
> >> >>>>> it is only a discussion between devs about the potential problems
> of
> >> >>>>> removing it. I totally understand Chesnay's concern about not
> >> >>>>> providing compatibility with the StreamingFileSink (SFS) and if
> there
> >> >>>>> are any users, then we should not remove it without trying to
> find a
> >> >>>>> solution for them.
> >> >>>>>
> >> >>>>> But if there are no users then I would still propose to remove the
> >> >>>>> module, given that I am not aware of any efforts to provide
> >> >>>>> compatibility with the SFS any time soon.
> >> >>>>> The reasons for removing it also include the facts that we do not
> >> >>>>> actively maintain it and we do not add new features. As for
> potential
> >> >>>>> missing features in the SFS compared to the BucketingSink that was
> >> >>>>> mentioned before, I am not aware of any fundamental limitations
> and
> >> >>>>> even if there are, I would assume that the solution is not to
> direct
> >> >>>>> the users to a deprecated sink but rather try to increase the
> >> >>>>> functionality of the actively maintained one.
> >> >>>>>
> >> >>>>> Please keep in mind that the BucketingSink is deprecated since
> FLINK
> >> >>>>> 1.9 and there is a new File Sink that is coming as part of
> FLIP-143
> >> >>>>> [1].
> >> >>>>> Again, if there are any active users who cannot migrate easily,
> then
> >> >>>>> we cannot remove it before trying to provide a smooth migration
> path.
> >> >>>>>
> >> >>>>> Thanks,
> >> >>>>> Kostas
> >> >>>>>
> >> >>>>> [1]
> https://cwiki.apache.org/confluence/display/FLINK/FLIP-143%3A+Unified+Sink+API
> >> >>>>>
> >> >>>>> On Fri, Oct 16, 2020 at 4:36 PM Chesnay Schepler <
> [hidden email]> wrote:
> >> >>>>>> @Seth: Earlier in this discussion it was said that the
> BucketingSink
> >> >>>>>> would not be usable in 1.12 .
> >> >>>>>>
> >> >>>>>> On 10/16/2020 4:25 PM, Seth Wiesman wrote:
> >> >>>>>>> +1 It has been deprecated for some time and the
> StreamingFileSink has
> >> >>>>>>> stabalized with a large number of formats and features.
> >> >>>>>>>
> >> >>>>>>> Plus, the bucketing sink only implements a small number of
> stable
> >> >>>>>>> interfaces[1]. I would expect users to continue to use the
> bucketing sink
> >> >>>>>>> from the 1.11 release with future versions for some time.
> >> >>>>>>>
> >> >>>>>>> Seth
> >> >>>>>>>
> >> >>>>>>>
> https://github.com/apache/flink/blob/2ff3b771cbb091e1f43686dd8e176cea6d435501/flink-connectors/flink-connector-filesystem/src/main/java/org/apache/flink/streaming/connectors/fs/bucketing/BucketingSink.java#L170-L172
> >> >>>>>>>
> >> >>>>>>> On Thu, Oct 15, 2020 at 2:57 PM Kostas Kloudas <
> [hidden email]> wrote:
> >> >>>>>>>
> >> >>>>>>>> @Arvid Heise I also do not remember exactly what were all the
> >> >>>>>>>> problems. The fact that we added some more bulk formats to the
> >> >>>>>>>> streaming file sink definitely reduced the non-supported
> features. In
> >> >>>>>>>> addition, the latest discussion I found on the topic was [1]
> and the
> >> >>>>>>>> conclusion of that discussion seems to be to remove it.
> >> >>>>>>>>
> >> >>>>>>>> Currently, I cannot find any obvious reason why keeping the
> >> >>>>>>>> BucketingSink, apart from the fact that we do not have a
> migration
> >> >>>>>>>> plan unfortunately. This is why I posted this to dev@ and
> user@.
> >> >>>>>>>>
> >> >>>>>>>> Cheers,
> >> >>>>>>>> Kostas
> >> >>>>>>>>
> >> >>>>>>>> [1]
> >> >>>>>>>>
> https://lists.apache.org/thread.html/r799be74658bc7e169238cc8c1e479e961a9e85ccea19089290940ff0%40%3Cdev.flink.apache.org%3E
> >> >>>>>>>>
> >> >>>>>>>> On Wed, Oct 14, 2020 at 8:03 AM Arvid Heise <
> [hidden email]> wrote:
> >> >>>>>>>>> I remember this conversation popping up a few times already
> and I'm in
> >> >>>>>>>>> general a big fan of removing BucketingSink.
> >> >>>>>>>>>
> >> >>>>>>>>> However, until now there were a few features lacking in
> StreamingFileSink
> >> >>>>>>>>> that are present in BucketingSink and that are being actively
> used (I
> >> >>>>>>>> can't
> >> >>>>>>>>> exactly remember them now, but I can look it up if everyone
> else is also
> >> >>>>>>>>> suffering from bad memory). Did we manage to add them in the
> meantime? If
> >> >>>>>>>>> not, then it feels rushed to remove it at this point.
> >> >>>>>>>>>
> >> >>>>>>>>> On Tue, Oct 13, 2020 at 2:33 PM Kostas Kloudas <
> [hidden email]>
> >> >>>>>>>> wrote:
> >> >>>>>>>>>> @Chesnay Schepler  Off the top of my head, I cannot find an
> easy way
> >> >>>>>>>>>> to migrate from the BucketingSink to the StreamingFileSink.
> It may be
> >> >>>>>>>>>> possible but it will require some effort because the logic
> would be
> >> >>>>>>>>>> "read the old state, commit it, and start fresh with the
> >> >>>>>>>>>> StreamingFileSink."
> >> >>>>>>>>>>
> >> >>>>>>>>>> On Tue, Oct 13, 2020 at 2:09 PM Aljoscha Krettek <
> [hidden email]>
> >> >>>>>>>>>> wrote:
> >> >>>>>>>>>>> On 13.10.20 14:01, David Anderson wrote:
> >> >>>>>>>>>>>> I thought this was waiting on FLIP-46 -- Graceful Shutdown
> >> >>>>>>>> Handling --
> >> >>>>>>>>>> and
> >> >>>>>>>>>>>> in fact, the StreamingFileSink is mentioned in that FLIP
> as a
> >> >>>>>>>>>> motivating
> >> >>>>>>>>>>>> use case.
> >> >>>>>>>>>>> Ah yes, I see FLIP-147 as a more general replacement for
> FLIP-46.
> >> >>>>>>>> Thanks
> >> >>>>>>>>>>> for the reminder, we should close FLIP-46 now with an
> explanatory
> >> >>>>>>>>>>> message to avoid confusion.
> >> >>>>>>>>> --
> >> >>>>>>>>>
> >> >>>>>>>>> Arvid Heise | Senior Java Developer
> >> >>>>>>>>>
> >> >>>>>>>>> <https://www.ververica.com/>
> >> >>>>>>>>>
> >> >>>>>>>>> Follow us @VervericaData
> >> >>>>>>>>>
> >> >>>>>>>>> --
> >> >>>>>>>>>
> >> >>>>>>>>> Join Flink Forward <https://flink-forward.org/> - The Apache
> Flink
> >> >>>>>>>>> Conference
> >> >>>>>>>>>
> >> >>>>>>>>> Stream Processing | Event Driven | Real Time
> >> >>>>>>>>>
> >> >>>>>>>>> --
> >> >>>>>>>>>
> >> >>>>>>>>> Ververica GmbH | Invalidenstrasse 115, 10115 Berlin, Germany
> >> >>>>>>>>>
> >> >>>>>>>>> --
> >> >>>>>>>>> Ververica GmbH
> >> >>>>>>>>> Registered at Amtsgericht Charlottenburg: HRB 158244 B
> >> >>>>>>>>> Managing Directors: Timothy Alexander Steinert, Yip Park Tung
> Jason, Ji
> >> >>>>>>>>> (Toni) Cheng
> >> >>
> >>
>

--
Best, Jingsong Lee