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The simplified rebalancing flow is illustratred on fugure:

TODO figImage Added

Update counters are used to determine the state when the one partition copy is behind the other(s).

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Otherwise, a situation is possible when the counter has increased, but there is no corresponding durable update.TODO describe how gaps are closed on normal flow

Crash recovery

There is no guarantee that this update will be completed, for example, if during the dht prepare transaction some nodes will exit, the transaction may be rolled back.
When a primary node fails under load situations may arise where may be permanent gaps in the updates on backup nodes in the event of transaction reordering.

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