# Tiflash Key Features: Asynchronous Replication
__*TiFlash asynchronous replication*__

![left](./student-guide/diagram/TiFlashAsyncRep_en_001_20220513.png)

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The image below shows TiFlash participating in TiKV replication. First of all, we know that the region data in TiFlash and TiKV's region are the same, but only the column store version is used.

Second, the region in TiFlash connects to TiKV's original Raft Group as a learner to form a new Raft Group. However, the region in TiFlash does not participate in voting or elect, and is not counted as a member of the majority. That is, if the Leader writes the majority follower, it can confirm that the data was written successfully, regardless of whether the learner node in TiFlash was written successfully or not. In this way, TiFlash is asynchronous replication, and the impact on TiKV's performance is very small.

Finally, TiFlash uses a fast update mechanism based on a primary key inside, so that although it is asynchronous, it does not have much delay with TiKV.