Great -- congratulations to everyone who has contributed to the Python SDK!

On Mon, Jan 30, 2017 at 11:10 PM, Ahmet Altay <al...@google.com.invalid>
wrote:

> Hi all,
>
> This merge is completed. Python SDK is now officially part of the master
> branch! Thank you all for the support. Please open an issue, if you notice
> a reference to the now obsolete python-sdk branch in the documentation.
>
> There will not be any more merges to the python-sdk branch. Going forward
> please use the master branch for Python SDK development. There are a few
> existing open PRs to the python-sdk [1]. If you are the author of one of
> those PRs, please rebase them on top of master.
>
> Thank you,
> Ahmet
>
> [1] https://github.com/pulls?utf8=✓&q=is%3Aopen+is%3Apr+base%
> <https://github.com/pulls?utf8=%E2%9C%93&q=is%3Aopen+is%3Apr+base%25>
> 3Apython-sdk+repo%3Aapache%2Fbeam+
> <https://github.com/pulls?utf8=%E2%9C%93&q=is%3Aopen+is%
> 3Apr+base%3Apython-sdk+repo%3Aapache%2Fbeam+>
>
> On Fri, Jan 20, 2017 at 10:06 AM, Kenneth Knowles <k...@google.com.invalid>
> wrote:
>
> > To clarify the implied criteria of that last exchange, it is "An SDK
> should
> > have at least one runner that can execute the complete model (may be a
> > direct runner)"
> >
> > I want to highlight this, because whether an _SDK_ supports unbounded
> data
> > is not particularly well-defined, and will evolve:
> >
> >  - With the Runner API, an SDK will need to support building a graph with
> > unbounded constructs, as today with probably minimal changes.
> >
> >  - With the Fn API, if any part of the Fn API is specific to unbounded
> > data, the SDK will need to implement it. I think right now there is no
> such
> > thing, and we don't want such a thing, so SDKs implementing the Fn API
> > automatically support unbounded data.
> >
> >  - There will also likely be an SDK-specific shim just as there is today,
> > to leverage idiomatic deserialized representations. The richness of this
> > shim will decrease so that it will need to "support" unbounded data but
> > that will be a ~one liner.
> >
> > Getting the Python SDK on master will accelerate our progress towards the
> > Fn API - partly technical, partly community - which is the best path
> > towards support for unbounded data across multiple runners. I think the
> > criteria are written with the completed portability framework in mind. So
> > this exchange makes me actually more convinced we should merge python-sdk
> > to master.
> >
> > On Fri, Jan 20, 2017 at 9:53 AM, Robert Bradshaw <
> > rober...@google.com.invalid> wrote:
> >
> > > On Thu, Jan 19, 2017 at 11:56 PM, Dan Halperin
> > > <dhalp...@google.com.invalid> wrote:
> > > > I do not think that Python SDK yet meets the bar [1] for implementing
> > the
> > > > Beam model -- supporting Unbounded data is very important. That said,
> > > given
> > > > the committed and sustained set of contributors, it generally makes
> > sense
> > > > to me to make an exception in anticipation of these features being
> > > fleshed
> > > > out soon; including potentially new users/contributors that would
> > arrive
> > > > once in master.
> > > >
> > > > [1] https://lists.apache.org/thread.html/CAAzyFAxcmexUQnbF=Y
> > > > k0plmm3f5e5bqwjz4+c5doruclnxo...@mail.gmail.com
> > >
> > > That is a valid point. The Python SDK supports all the unbounded parts
> > > of the model except for unbounded sources, which was deferred while
> > > seeing how https://s.apache.org/splittable-do-fn played out. I've been
> > > working with the team and merging/reviewing most of their code, and
> > > have full confidence this will be coming (and on that note can vouch
> > > for a healthy community and support which are much harder to add
> > > later).
> > >
> > > In short, I think it has the required maturity, and I'm in favor of
> > > merging soonish.
> > >
> > > > On Wed, Jan 18, 2017 at 12:24 AM, Ahmet Altay
> <al...@google.com.invalid
> > >
> > > > wrote:
> > > >
> > > >> Thank you all for the comments so far. I would follow the process as
> > > >> suggested by Davor and others in this thread.
> > > >>
> > > >> Ahmet
> > > >>
> > > >> On Tue, Jan 17, 2017 at 11:47 PM, Sergio Fernández <
> wik...@apache.org
> > >
> > > >> wrote:
> > > >>
> > > >> > Hi
> > > >> >
> > > >> > On Tue, Jan 17, 2017 at 5:22 PM, Ahmet Altay
> > <al...@google.com.invalid
> > > >
> > > >> > wrote:
> > > >> > >
> > > >> > > tl;dr: I would like to start a discussion about merging
> python-sdk
> > > >> branch
> > > >> > > to master branch. Python SDK is mature enough and merging it to
> > > master
> > > >> > will
> > > >> > > accelerate its development and adoption.
> > > >> > >
> > > >> >
> > > >> > Good point, Ahmet!
> > > >> >
> > > >> > I've following closed the development since it was imported in
> June.
> > > For
> > > >> > the prototypes I've implemented so far it works quite well; I
> guess
> > > we'd
> > > >> > just need to focus the next months in bringing more runners
> support.
> > > >> >
> > > >> > With a great effort from a lot of contributors(*), Python SDK [1]
> is
> > > now
> > > >> a
> > > >> > > mostly complete, tested, performant Python implementation of the
> > > Beam
> > > >> > > model. Since June, when we first started with Python SDK in
> Apache
> > > Beam
> > > >> > we
> > > >> > > have been continuously improving it.
> > > >> > >
> > > >> >
> > > >> > I wouldn't merge during the preparation of 0.5.0 release, but
> after
> > > that
> > > >> > could be a good time to merge back into master.
> > > >> >
> > > >> >
> > > >> > ** Python SDK currently supports:
> > > >> > >
> > > >> > > * Model: All main concepts are present (ParDo, GroupByKey,
> > Windowing
> > > >> > etc.).
> > > >> > > * IO: There are extensible APIs for writing new bounded sources
> > and
> > > >> > sinks.
> > > >> > > Implementations are provided for Text, Avro, BigQuery, and
> > > Datastore.
> > > >> > > * Runners: Python SDK has an extensible base runner module that
> > > allows
> > > >> > > building specific runners on top of it. The SDK comes with two
> > > pipeline
> > > >> > > runners: DirectRunner and DataflowRunner; and it is possible to
> > add
> > > >> more.
> > > >> > > The existing runners are currently limited to bounded execution
> > and
> > > >> > > otherwise equivalent to their Java SDK counterparts in
> > > functionality.
> > > >> > >
> > > >> >
> > > >> > What would the effort of porting, and maintaining, parallel
> versions
> > > of
> > > >> the
> > > >> > Java runners? I guess I'd need to dig deeper in the model, but
> this
> > > may
> > > >> > represent a major effort for the project, right?
> > > >> >
> > > >>
> > > >> It is somewhat higher for DirectRunner because DirectRunner also
> > > implements
> > > >> the code for execution. It is not that high for DataflowRunner
> because
> > > the
> > > >> base runner module has a lot of helpers with the right hooks for
> > > >> implementing a generic runner. I would _expect_ the experience in
> > > general
> > > >> would be similar to the latter.
> > > >>
> > > >>
> > > >> >
> > > >> >
> > > >> >
> > > >> > > * Testing: Python SDK implements ValidatesRunner test framework
> > for
> > > >> > > implementing integration test for current and future runners.
> > There
> > > is
> > > >> > unit
> > > >> > > test coverage for all modules, and a number of integrations test
> > for
> > > >> > > validating existing runners.
> > > >> > > * Documentation and examples: Documentation work has started on
> > > Python
> > > >> > SDK.
> > > >> > > Beam Programming Guide page has been updated to include Python
> > [2].
> > > The
> > > >> > > code comes with many ready to use examples and we are in a good
> > > place
> > > >> to
> > > >> > > start documenting those on the website.
> > > >> > >
> > > >> > > ** We are not done yet, next on the roadmap we have:
> > > >> > >
> > > >> > > * Streaming: Both of the existing runners lack support for
> > streaming
> > > >> > > execution, and currently there is work going on for adding
> > streaming
> > > >> > > support to DirectRunner [3].
> > > >> > > * Documentation: Filling the rest of the Beam documentations
> with
> > > >> Python
> > > >> > > SDK specific information and examples.
> > > >> > > * SDK consistency: Making Python SDK consistent with the Java
> SDK.
> > > We
> > > >> > have
> > > >> > > come a long way on this and have only a few items left [4].
> > > >> > > * Beamifying: We have been working on removing Dataflow-specific
> > > >> > references
> > > >> > > both from the documentation and from the code. There is some
> work
> > > left,
> > > >> > and
> > > >> > > we are currently working on those as well [5].
> > > >> > >
> > > >> > > ** Steps and implications of merging to master:
> > > >> > >
> > > >> > > * Master branch is merged to python-sdk branch at regular
> > intervals
> > > and
> > > >> > the
> > > >> > > last merge was on 12/22. All the past merges were uneventful
> > because
> > > >> > there
> > > >> > > is a minimal overlap in modified files between branches.
> > Integrating
> > > >> > > python-sdk to master will similarly touch a small number of
> > existing
> > > >> > files.
> > > >> > >
> > > >> > > * Python SDK is using the same tools for building and testing.
> It
> > is
> > > >> > > already integrated with Maven, Jenkins and Travis. Specifically
> > the
> > > >> > impact
> > > >> > > to the testing infrastructure would be:
> > > >> > > - There will be two additional test configurations in Travis.
> > Since
> > > >> > Travis
> > > >> > > runs all configurations in parallel there should not be a
> > noticeable
> > > >> > change
> > > >> > > in the Travis run time.
> > > >> > > - Jenkins pre-commit test will start running the Python SDK
> tests.
> > > It
> > > >> > will
> > > >> > > add an additional 5 minutes to the completion time of pre-commit
> > > test.
> > > >> > > Historically Python SDK tests were not flaky and did not cause
> any
> > > >> random
> > > >> > > failures.
> > > >> > > - Jenkins Python post-commit test is already separated from the
> > > other
> > > >> > > post-commit tests and will continue to exist. It would not
> change
> > > the
> > > >> > > testing time for any other test.
> > > >> > >
> > > >> > > * The release process needs to be updated to accommodate
> releasing
> > > >> Python
> > > >> > > artifacts. Python SDK would fit in the existing release schedule
> > and
> > > >> > could
> > > >> > > be released along with the Java SDK. The additional steps would
> > > >> include:
> > > >> > > - Generating Python artifacts. This could be done with a single
> > > command
> > > >> > > using Maven today.
> > > >> > > - Publishing the artifacts to a central repository such as PyPI.
> > > >> > >
> > > >> >
> > > >> > I'm more than happy to help on this. We left on purpose some
> things
> > > open
> > > >> > when we added Maven support to the Python build.
> > > >> >
> > > >>
> > > >> That would be awesome. We can coordinate on that post-merge.
> > > >>
> > > >>
> > > >> >
> > > >> >
> > > >> >
> > > >> > > - Updating the release guide to reflect the changes above.
> > > >> > >
> > > >> > > * Users: There are existing users using the Python SDK. To give
> a
> > > rough
> > > >> > > estimate, a distribution of the Beam Python SDK had a total of
> 23K
> > > >> > > downloads in the past 6 months [6]. Some of those users are
> > already
> > > >> > engaged
> > > >> > > with the community (e.g. [7]). There might be an increased
> amount
> > > >> > > engagement from the rest of them after the merge.
> > > >> > >
> > > >> >
> > > >> > Python 3 support is something we definitively need to look ahead.
> > I'd
> > > try
> > > >> > to make the codebase compatible with both 2.7.x and 3.6.x, rather
> > than
> > > >> > using other  solutions like 2to3.
> > > >> >
> > > >>
> > > >> I agree with you. I think it makes more sense to make codebase
> > > compatible
> > > >> with both. As you mentioned Python 3 support is not a short-term
> goal
> > in
> > > >> the roadmap, and we can discuss it more as we approach that.
> > > >>
> > > >>
> > > >> >
> > > >> >
> > > >> > Looking forward to hearing your thoughts and comments on
> > “graduating”
> > > >> > > python-sdk to the master.
> > > >> > >
> > > >> > > Thank you,
> > > >> > > Ahmet
> > > >> > >
> > > >> > > (*) Python SDK branch currently has a diverse group of
> > contributors.
> > > >> > > Regular contributors include Charles Chen, Chamikara Jayalath,
> > María
> > > >> > García
> > > >> > > Herrero, Mark Liu, Pablo Estrada, Robert Bradshaw (Apache Beam
> > PMC),
> > > >> > > Sourabh Bajaj, and Vikas Kedigehalli. We have also had
> > contributions
> > > >> from
> > > >> > > Abdullah Bashir, Marco Buccini, Sergio Fernández, Seunghyun Lee,
> > and
> > > >> > > Younghee Kwon.
> > > >> > >
> > > >> > > [1] https://github.com/apache/beam/tree/python-sdk/sdks/python
> > > >> > > [2] https://beam.apache.org/documentation/programming-guide/
> > > >> > > [3] https://issues.apache.org/jira/browse/BEAM-1265
> > > >> > > [4]
> > > >> > > https://issues.apache.org/jira/issues/?jql=status%20%3D%20Op
> > > >> > > en%20AND%20labels%20%3D%20sdk-consistency
> > > >> > > [5] https://issues.apache.org/jira/browse/BEAM-1218
> > > >> > > [6] https://pypi.python.org/pypi/google-cloud-dataflow/json
> > > >> > > [7] https://issues.apache.org/jira/browse/BEAM-1251
> > > >> > >
> > > >> >
> > > >> >
> > > >> > Great summary, Ahmet. Thanks.
> > > >> >
> > > >> > Cheers,
> > > >> >
> > > >> > --
> > > >> > Sergio Fernández
> > > >> > Partner Technology Manager
> > > >> > Redlink GmbH
> > > >> > m: +43 6602747925
> > > >> > e: sergio.fernan...@redlink.co
> > > >> > w: http://redlink.co
> > > >> >
> > > >>
> > >
> >
>

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