Eliaaazzz commented on code in PR #40091: URL: https://github.com/apache/beam/pull/40091#discussion_r3986058424
########## website/www/site/content/en/blog/python-unboundedsource-watch.md: ########## @@ -0,0 +1,163 @@ +--- +title: "UnboundedSource and the Watch Transform in the Apache Beam Python SDK" +date: 2026-09-10T00:00:00+10:00 +categories: + - blog + - gsoc +authors: + - eliaaazzz +--- +<!-- +Licensed under the Apache License, Version 2.0 (the "License"); +you may not use this file except in compliance with the License. +You may obtain a copy of the License at + +http://www.apache.org/licenses/LICENSE-2.0 + +Unless required by applicable law or agreed to in writing, software +distributed under the License is distributed on an "AS IS" BASIS, +WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +See the License for the specific language governing permissions and +limitations under the License. +--> + +The Apache Beam Python SDK now includes an `UnboundedSource` API for custom Review Comment: Convenience, mainly. An unbounded splittable DoFn could already do this, but the learning curve is steep: you model the reader's position as a restriction, decide when to stop and hand progress back, and drive a watermark estimator, all before writing code that talks to your queue. `UnboundedSource` asks for `start()`, `advance()`, `get_watermark()` and a checkpoint mark, and the wrapper handles the SDF part. That is what makes a source for your own message broker or a database change feed reasonable to write in Python. `Watch` is the same idea for an input that keeps growing. The Motivation section now says this. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
