# High Availability Features Of Tidb Servers

+ Stateless:
  + Data is stored by TiKV
  + No communication between TiDB (via TiKV and PD)
  + Add or remove at any time
+ Does not support failover itself and requires business cooperation


![left](./student-guide/diagram/28-TiDB-High-availability-feature-01-01.png)

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 Stateless:
 Data is stored by TiKV
 No communication between TiDB (via TiKV and PD)
 Add or remove at any time
 Does not support failover itself and requires business cooperation