[BP-2.3][FLINK-39436][FLINK-39437][table] Backport of two PTF fixes#27998
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fhueske merged 2 commits intoapache:release-2.3from Apr 22, 2026
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Previously, late events (rowtime <= watermark) were silently dropped before reaching PTF eval(), and timer registrations for times <= watermark were also silently dropped. This change removes both restrictions: - ProcessTableRunner: remove the early-return guard in processEval() so that late events are passed to the PTF's eval() method. - WritableInternalTimeContext: remove the watermark check in registerOnTimeInternal() so that timers can be registered for past times. Such timers fire immediately at the next watermark advance, including when registered from within onTimer(). The previous guard also had an unintended side effect: any call to replaceNamedTimer() with a past time would delete the existing timer entry but then silently drop the new registration, leaving the named timer in a state where it appeared un-registered but the old timer was gone. - AbstractProcessTableOperator: remove the fired named timer's state entry before invoking onTimer() to prevent stale entries from accumulating in the named timers map state. Tests are updated to reflect the new semantics: - PROCESS_LATE_EVENTS: demonstrates that late events enter eval(), can register timers (including for past times), and that such timers fire immediately at the next watermark advance. - PROCESS_ROW_LATE_EVENTS (new): verifies the same for row-semantics PTFs. - PROCESS_OPTIONAL_ON_TIME / PROCESS_NAMED_TIMERS: updated to reflect that timer registrations for past times are no longer dropped. Previously, once the watermark passed the registered time, the timer was silently discarded; now it fires immediately.
Override `useInterruptibleTimers()` in `AbstractProcessTableOperator` to return `true`, activating the `MailboxWatermarkProcessor` for PTF operators. This allows timer firing to be interrupted between mailbox iterations, improving throughput by not blocking mailbox processing during large timer batches. Also removes `currentWatermark` from `ProcessTableRunner` and redirect reads to `AbstractStreamOperatorV2.combinedWatermark`. Add a test (`ProcessSetTableOperatorInterruptibleTimersTest`) to assert correct behavior of PTF framework when timer processing is interrupted.
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twalthr
approved these changes
Apr 22, 2026
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Backport of [FLINK-39436] (PR #27935) and [FLINK-39437] (PR #27962) to
release-2.3.These changes fix limitation of the PTF framework.