Redis

Redis is an ANSI C, open source, network-supported, memory-based key-value pairs storage database with optional persistence.

Memcached

Memcached is an open source, memory-based and high-speed KV cache system that does not support the data persistence.

Instance

Each instance corresponds to a cloud database SCS for Redis service entity, which is the basic unit to use the cloud database SCS for Redis service; each instance is identified with a unique instance ID, and the user can see the list of instances purchased in the console.

Multipart

A multipart is a set of cache nodes. Depending on the number of selected replicas, each multipart contains a different number of cache nodes. When an instance contains several multiparts, the data set is assigned into several multiparts, and there is a subset of the complete data set in each multipart.

Standard Instance

Redis instance with the standard architecture contains only one multipart. It is compatible with protocols and commands for Redis 3.2/4.0 version and is the most common instance type.

Cluster Instance

Redis instance with cluster architecture contains several multiparts and multiple proxy nodes. It is compatible with Redis 3.2 version of protocols and commands, adopts a distributed architecture, and supports horizontal and vertical capacity expansion (will be put into use). The cluster instance can expand the data capacity and improve network/CPU/QPS capabilities quickly by horizontally expanding the number of multiparts, and can carry much higher traffic capacity than the standard version of instances.

Single Replica

A single multipart contains only one node, which acts as a read-write master node. A single-replica instance supports high read and write concurrency, but does not support backup or persistence and does not provide data reliability; it is suitable for business scenarios with low cache data reliability.

Dual Replica

A single multipart contains 2 nodes, of which one acts as a read-write primary node, and the other one acts as standby node that cannot be read or written and is not visible to the user. When the master node fails, the standby node is automatically upgraded to the master node. The dual-replica instance supports failover in seconds, backup and persistence, with high reliability and high availability, and is suitable for various application scenarios.

Link Address

It is the domain name/IP address to link the cloud database SCS for Redis instance.

Link Password

It is the password to link the cloud database SCS for Redis Instance .

Replacement Policy

It is consistent with the that for the open source version.