KIP-539 — Add mechanism to flush records out in low volume suppression buffers

Discussion Streams

KIP-539 adds a `Suppressed.untilWallClockTimeLimit(Duration, BufferConfig)` factory method that flushes suppression buffer entries based on wall-clock elapsed time rather than waiting indefinitely for stream time to advance. In low-traffic scenarios, stream time cannot advance because no new records arrive to update it, leaving buffered records permanently stuck in suppression operators and preventing downstream results from being emitted.

Details