Relevant Parameter

Item	Description
DB Number Restriction	Non-cluster version instances support 256 DBs with a range of [0,255]; cluster version instances support 1 DB with a range of [0].
Data Persistence Policy	Self-developed persistence method combining RDB+AOF, and flushing policy "everysec".
Expired Data Deletion Policy	Active expiration. The system runs detection periodically, and when it detects an expired key, it deletes the key. Lazy deletion. When a key is accessed, it is deleted if it has expired.
Backup Data Retention Policies	Manual backup and periodic backup, and the number of replicas cannot exceed 3.
Strong Consistency Configuration	When it is enabled, the system checks the active-standby data synchronization delay if an active/standby switchover is required. If there is a long delay, the switchover will not happen, reducing node availability while increasing data reliability. Whether to enable it depends on your application requirements.
Redis Engine Versions	Supports versions 2.8, 4.0, 5.0, 6.0, and 7.0. Among them, version 5.0 is backward compatible with versions 4.0 and 2.8.

Instance Name Restrictions

The instance name cannot be modified after you enter and confirm it on the activation page; during the authentication process, the instance name is associated with authentication processing to improve instance security and isolation.

Change Specifications

Specification changes consist of expansion and type changes. Expansion occurs within the same series. For example, a stand-alone 2G is changed to a stand-alone 4G; the type changes occur when a standard version stand-alone is upgraded to a standard version active/standby, or when a cluster version stand-alone is upgraded to a cluster version active/standby; jitters may occur during the specification change, so it is recommended to change specifications during off-peak hours. After the specifications are changed, the backup replicas generated by manual backup and periodic backup are unavailable, but the backup operation can be performed again.

Usage Suggestions

Data size: The recommended size of a single record (key+value) is no more than 32K.

Memory Usage: It is recommended that the memory utilization of a Redis instance not exceed 90%, and the best utilization range is 60-70%; keep 20% of the space idle for sudden traffic and instance O&M.

Reduce the frequency of cross-node command and re-command usage: control the frequency of re-operation commands such as scan fuzzy matching, hgetall and so on.

Parameter Specifications

Instance name restrictions: contains any three types of digits, uppercase letters, lowercase letters and special characters (except #), 8 to 32 characters in length.

Instance password restrictions: contains any three types of digits, uppercase letters, lowercase letters and special characters (except #), 8 to 32 characters in length.

Explanation of Terms

Instance ID	Identifier of Each Instance
Instance Password	Auth authentication password. Cluster version instance password: instance name#instance password; standard version instance: instance password.
DB	Redis database, with a range of [0,255].
Number of Redis Connections	The number of connections between theFrontend and each Redis node.
Number of Idle Redis Connections	The number of idle connections between theFrontend and each Redis node.
Maximum Number of Client Connections	The maximum number of connections a client can create.

DCS Redis Help Documentation

Usage Notes