Instance Architecture

Description

Application Scenario

Cluster

A DDS cluster consists of three types of nodes: Mongos, Shard, and Config. You can configure the number of Mongos and shard nodes as required. Each Mongos is a single node, and each Shard and Config is a three-node replica set.

Cluster instances are recommended for service systems that require both high availability and scalability.

Replica Set

A Replica Set consists of three nodes: primary, secondary, and hidden. You can operate the primary and secondary nodes directly. High Availability (HA) and Disaster Recovery (DR) switchover are provided and are unnoticeable to applications.

Replica set instance suits small- and medium-sized service systems that require high availability.

Single Node

A database that is deployed on a single VM does not have the HA feature. To ensure data consistency during full backup, tables are locked to prevent data from being changed.

The single-node architecture features low costs and is a preferred option for R&D and testing environment, learning and training environment, and internal systems of small-sized enterprises.