# Scheduling: `Operator`

+ `Checker/Scheduler` will generate the operators to perform the actual actions
  + `Operator` will be added to a queue to wait for being executed 
  + `Region` is the one to execute the `operator`, so the `operator` is dispatched by the `region` heartbeat response in batch
+ Each `operator` may contain multiple steps
  + For example, a `move-region operator` looks like:
    + **_Step 1:_** Add a `learner peer` on the target `store`
    + **_Step 2:_** Promote the `learner peer`
    + **_Step 3:_** Remove the old `peer`

![`smart`](OperatorCreation_aa_001_20221024.png)

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