sohailshk opened a new issue, #41193: URL: https://github.com/apache/beam/issues/41193
### What happened? `MonotonicWatermarkEstimator.default_provider()` creates the estimator with an initial state of `None` (as its docstring says: "For a new <element, restriction> pair, the initial value is None"). After the DoFn observes a timestamp, `current_watermark()` compares it with that `None`: ```python from apache_beam.io.watermark_estimators import MonotonicWatermarkEstimator from apache_beam.utils.timestamp import Timestamp e = MonotonicWatermarkEstimator(None) e.observe_timestamp(Timestamp(15)) e.current_watermark() # TypeError: '>=' not supported between instances of 'Timestamp' and 'NoneType' ``` The SDK harness reads `current_watermark()` when it splits or defers the element, so a splittable DoFn that uses `MonotonicWatermarkEstimator.default_provider()` and observes timestamps fails there. ### Issue Priority Priority: 2 (default / most bugs should be filed as P2) ### Issue Components - [x] Component: Python SDK -- 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]
