# Asynchronous Replication
+ Asynchronous replication using TiDB binlog or TiDC components
+ Will lose data RPO is not 0
+ Guaranteed consistency after damage recover
+ High availability features on the primary cluster or from within the cluster


![left](./student-guide/diagram/29-Async-replication-01-01.png)
------------------------------------------------------------
The asynchronous replication scheme of TiDB databases mainly adopts the master-slave architecture, that is, one master cluster plus one slave cluster, and relies on TiDB binlog or TiDC for asynchronous replication. When the primary cluster is unavailable, we can switch to the slave cluster, but because of asynchronous replication, data will be lost (RPO is not 0). TiDB binlog and TiDC guarantee the consistency of asynchronous replication.

The primary cluster or slave cluster can choose a multi-center plan in the same city, so that it has high availability within the master and slave clusters.

The characteristics are as follows:
- Asynchronous replication using TiDB binlog or TiDC components
- Data will be lost (RPO not 0)
- Guaranteed consistency after damage recover
- High availability features on the primary cluster or from within the cluster