DynamoDB 自适应扩展如何重新平衡分区？

Question

In the DynamoDB doc, it is written:

If your application drives disproportionately high traffic to one or more items, adaptive capacity rebalances your partitions such that frequently accessed items don't reside on the same partition.

My question is:

what exactly is meant by “rebalance”?

Are some items copied to a new partition and removed from the original one?

Does this process impact performance?

How long does it take?

Answer 1

Items are split across two new partitions. The split initiates when the database decides there's been enough sustained traffic in a spread pattern where a split would be beneficial, and then the split itself takes a few minutes. In testing with on-demand tables (where I created synthetic sustained traffic) I've seen the throughput double and then double again, repeating about every 15 minutes.