In an ApsaraDB for Redis instance, the master node asynchronously synchronizes data to replica nodes by default. As such, a synchronization latency exists and may cause data in the replica nodes to be different from that in the master node at certain points in time.
Data inconsistency occurs because of one of the following reasons:
The replica nodes that synchronize data from the master node are overwhelmed by write I/O operations on the master node.
A network latency exists when the replica nodes synchronize data from the master node.
ApsaraDB for Redis