How Does Redis Master/Standby Replication Work?

Redis master/standby instances are also called master/slave instances. Generally, updates to the master cache node are automatically and asynchronously replicated to the standby cache node. This means that data in the standby cache node may not always be consistent with data in the master cache node. The inconsistency is typically seen when the I/O write speed of the master node is faster than the synchronization speed of the standby node or a network latency occurs between the master and standby nodes. If a failover happens when some data is not yet replicated to the standby node, such data may be lost after the failover.