# High Availability
+ Service High Availability 
  + `nodeSelector`
  + `toleration` & `affinity`
  + `topologySpreadConstraints`

+ Data High Availability
  + Cluster typology configuration
  + Set labels for `Placement Drivers`
  + Set labels for `TiKV` nodes



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`TiDB Operator` provides a custom scheduler that guarantees `TiDB` service can tolerate host-level failures through the specified scheduling algorithm. 

Currently, the `TiDB` cluster uses this scheduler as the default scheduler, which is configured through the item `spec.schedulerName`.