[BEAM-11481] FlinkRunner might not advance output watermark on change of watermark hold

• Type: Bug
• Status: Resolved
• Priority: P0
• Resolution: Fixed
• Affects Version/s: 2.25.0, 2.26.0
• Fix Version/s: 2.27.0
• Component/s: runner-flink
• Assignee: Jan Lukavský
• Reporter: Jan Lukavský
• Created: 17/Dec/20 10:40
• Updated: 28/Dec/20 15:03
• Resolved: 21/Dec/20 10:49

Description

Output watermark of DoFnOperator is advanced only when new input watermark is received. The output watermark might advance even on timer or processed element due to updated watermark hold. This especially holds true in splittable DoFn.

Issue Links

• links to: GitHub Pull Request #13571
• links to: GitHub Pull Request #13582