# Split

+ New groups are generated by splitting
+ When to split:
  + By size and key count
    + Avoid read/write skew
  + By load
    + Handle hot spot
+ How to split:
  + Split logically, only metadata are changed
  + Version is increased by 1 for each split

![`smart`](RaftRegionSplit_aa_001_20221023.png)

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