Yes, I'm having a PR[1] under reviewing to update the IO development guide.

[1] https://github.com/apache/beam/pull/13227
<https://github.com/apache/beam/pull/13227>

On Fri, Nov 27, 2020 at 8:00 AM Alexey Romanenko <[email protected]>
wrote:

> Seems like the documentation about creating new IO connectors [1] is out
> of date and it makes people get confused about the recommended way of
> developing :
>
> *“Splittable DoFn is a new sources framework that is under development and
> will replace the other options for developing bounded and unbounded
> sources.*"
>
> Do you think we need rewrite this section completely according to a large
> progress with moving to SDF-based connectors in last time? Though, it would
> be useful to keep an old (current) one since Source API is still used.
>
>
> [1] https://beam.apache.org/documentation/io/developing-io-overview/
>
> On 25 Nov 2020, at 19:37, Boyuan Zhang <[email protected]> wrote:
>
> +dev <[email protected]>
>
> Hi Bashir,
>
> Most recently we are recommending to use Splittable DoFn[1] to build new
> IO connectors. We have several examples for that in our codebase:
> Java examples:
>
>    - Kafka
>    
> <https://github.com/apache/beam/blob/571338b0cc96e2e80f23620fe86de5c92dffaccc/sdks/java/io/kafka/src/main/java/org/apache/beam/sdk/io/kafka/ReadFromKafkaDoFn.java#L118>
>    - An I/O connector for Apache Kafka <https://kafka.apache.org/> (an
>    open-source distributed event streaming platform).
>    - Watch
>    
> <https://github.com/apache/beam/blob/571338b0cc96e2e80f23620fe86de5c92dffaccc/sdks/java/core/src/main/java/org/apache/beam/sdk/transforms/Watch.java#L787>
>    - Uses a polling function producing a growing set of outputs for each input
>    until a per-input termination condition is met.
>    - Parquet
>    
> <https://github.com/apache/beam/blob/571338b0cc96e2e80f23620fe86de5c92dffaccc/sdks/java/io/parquet/src/main/java/org/apache/beam/sdk/io/parquet/ParquetIO.java#L365>
>    - An I/O connector for Apache Parquet <https://parquet.apache.org/>
>    (an open-source columnar storage format).
>    - HL7v2
>    
> <https://github.com/apache/beam/blob/6fdde4f4eab72b49b10a8bb1cb3be263c5c416b5/sdks/java/io/google-cloud-platform/src/main/java/org/apache/beam/sdk/io/gcp/healthcare/HL7v2IO.java#L493>
>    - An I/O connector for HL7v2 messages (a clinical messaging format that
>    provides data about events that occur inside an organization) part of 
> Google’s
>    Cloud Healthcare API <https://cloud.google.com/healthcare>.
>    - BoundedSource wrapper
>    
> <https://github.com/apache/beam/blob/571338b0cc96e2e80f23620fe86de5c92dffaccc/sdks/java/core/src/main/java/org/apache/beam/sdk/io/Read.java#L248>
>    - A wrapper which converts an existing BoundedSource implementation to a
>    splittable DoFn.
>    - UnboundedSource wrapper
>    
> <https://github.com/apache/beam/blob/571338b0cc96e2e80f23620fe86de5c92dffaccc/sdks/java/core/src/main/java/org/apache/beam/sdk/io/Read.java#L432>
>    - A wrapper which converts an existing UnboundedSource implementation to a
>    splittable DoFn.
>
>
> Python examples:
>
>    - BoundedSourceWrapper
>    
> <https://github.com/apache/beam/blob/571338b0cc96e2e80f23620fe86de5c92dffaccc/sdks/python/apache_beam/io/iobase.py#L1375>
>    - A wrapper which converts an existing BoundedSource implementation to a
>    splittable DoFn.
>
>
> [1]
> https://beam.apache.org/documentation/programming-guide/#splittable-dofns
>
> On Wed, Nov 25, 2020 at 8:19 AM Bashir Sadjad <[email protected]> wrote:
>
>> Hi,
>>
>> I have a scenario in which a streaming pipeline should read update
>> messages from MySQL binlog (through Debezium). To implement this pipeline
>> using Beam, I understand there is a KafkaIO which I can use. But I also
>> want to support a local mode in which there is no Kafka and the messages
>> are directly consumed using embedded Debezium because this is a much
>> simpler architecture (no Kafka, ZooKeeper, and Kafka Connect).
>>
>> I did a little bit of search and it seems there is no IO connector for
>> Debezim, hence I have to implement one following this guide
>> <https://beam.apache.org/documentation/io/developing-io-java/>. I wonder:
>>
>> 1) Does this approach make sense or is it better to rely on Kafka even
>> for the local single machine use case?
>>
>> 2) Beside the above guide, is there any simple example IO that I can
>> follow to implement the UnboundedSource/Reader? I have looked at some
>> examples here <https://github.com/apache/beam/tree/master/sdks/java/io> but
>> was wondering if there is a recommended/simple one as a tutorial.
>>
>> Thanks
>>
>> -B
>> P.S. If this is better suited for dev@, please feel free to move it to
>> that list.
>>
>
>

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