What happened?

This shows up in Dataflow as the errors in harness logs:
generic::invalid_argument: SDK reported a smaller watermarkhold: 2025-09-11T02:45:27.292+00:00 than the computed lower bound: 2025-09-11T02:51:11.775+00:00

Partitions are added to the metadata table with their start timestamp. The detectnewchangestreams fn outputs new restrictions for these partitions with the minimum watermark of all partitions and then during processing of a partition the timestamp is strictly increasing.

This was root-caused to possible reordering of updating watermarks in the metadata table. It is exacerbated by watermark caching and filtering that was added to change streams in 2.67.

Issue Priority

Priority: 2 (default / most bugs should be filed as P2)

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