Perform periodic flush of ManagedCursor mark-delete posistions #8634
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merlimat
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Motivation
The updates on the managed cursor are (by default) rate limited to avoid generating a lot of write operations when consumers are acknowledging messages.
Due to the nature of the rate limiting, if the traffic on topic suddenly stops, the last updates to the cursor position are kept only in memory and they would be flushed only in 2 conditions, either:
If the topic is not gracefully closed, the cursor will be rolled back to the last persisted position.
That will trigger re-delivery of potentially very old messages. Instead we should have a time-bound period after which we ensure that all cursor updates are flushed on disk.