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F(4) = s2, s3, s1
F(5) = s3, s1, s2
First node in the list corresponds to primary node, others are backups. Only list prefix equal in size to owners count is used, other nodes are ignored.
In real life results might not be so ideal because of hash randomization causing some nodes to have slightly more partitions then others. It depends on total partitions counter - the more total partitions count the more uniform is assignment.
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Each update to a partition receives a sequential number for a purpose of ensuring data consistency between copies. A special structure called partition update counter is used to assign and increment update counters.
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