Notes and Constraints

Instance version

Currently, DCS supports Redis 4.0, 5.0, and 6.0.

Redis instances cannot be upgraded, but data of an earlier instance can be migrated to a later one.

Data persistence

• Not available for single-node instances.
• Master/Standby, read/write splitting, and cluster (except single-replica cluster) instances: Data persistence is supported by default.

Read/Write splitting

• Read/Write splitting instances: Read/Write splitting is implemented on the server by default.
• Redis Cluster and master/standby instances: Read/Write splitting is implemented on the client, which requires manual configurations.
• Read/Write splitting is not supported for other instances.

Data backup

Automatic or manual data backup is supported on the console for instances other than single-node ones.

VPC and subnet

Fixed once the instance is created.

Changing Redis instance specifications or types

• You are advised to change instances during off-peak hours. Otherwise, the change may fail.
• Change the replica quantity and capacity separately.
• Only one replica can be deleted per operation.
• For more information, see Modifying Specifications.

Version upgrade

To migrate an instance, the target instance version must be later than the source one. Migrating a later instance to an earlier one may fail.

Online migration

• To migrate Redis instances online on the DCS console, the network between the source and target must be connected and the SYNC and PSYNC commands must be allowed on the source.
• You cannot use public networks for online migration.
• The source must be Redis 3.0 or later.
• You are advised to perform online migration during off-peak hours. Otherwise, the CPU usage of the source instance may surge and the latency may increase.

IP switch

• The IP addresses and domain names of the source and target DCS Redis instances can be switched on the console after the source instance is fully and incrementally migrated.
• Unavailable for Redis Cluster instances.