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Rebalancing - a procedure for exchanging data between nodes to ensure uniform distribution of data (redistribution of data between nodes) according to affinity assignment [1] and to ensure data consistency if copies diverge [2].
[1] Partition state based rebalancing
In the first case, the reason for the rebalancing is a change in the list of nodes - owners of the partition. If a new node has joined the topology then part of the partitions will be reassigned to it due to the affinity function property of the uniform distribution of partitions among the nodes. If the node is left then the re-balance will be triggered to ensure the availability of the required number of copies of the partition in the grid.
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