Updated on 2026-09-24 GMT+08:00

Getting Started with DDS

This section describes DDS instance and product types, helping you quickly create and connect to a DDS instance.

How Do I Select a Cluster, Replica Set, or Single Node?

DDS supports different deployment architectures, such as cluster, replica set, and single node, meeting requirements of different service scenarios.

Table 1 Instance types

DB Instance Type

Application Scenario

Cluster

A cluster consists of three types of nodes: dds mongos, shard, and config. You can select the number of dds mongos and shard nodes and the cluster configuration you need based on your performance requirements.

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. Disaster recovery and high availability are provided for replica set instances without being noticed by the upper-layer 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. As a supplement to the cluster and replica set architectures, the single-node architecture is useful for R&D, testing, and non-core data storage of enterprises.

NOTE:

Huawei Cloud has discontinued the sale of DDS single node instances since July 15, 2023.

Connection Methods

DDS provides multiple connection methods. You can connect to a DDS instance through a private network, public network, or Data Admin Service (DAS). For details, see Table 3. Data Admin Service (DAS) enables you to manage DB instances on a web-based console, simplifying database management and improving working efficiency. You can connect to and manage DB instances through DAS. By default, you have the remote login permission. Using DAS to connect to your DB instance is recommended, which is more secure and convenient.

Table 2 Connection methods

Connection Method

IP Address

Scenario

Description

Connection using DAS

No IP address required

DAS provides GUI-based data management functions, allowing you to perform operations directly in the console. The functions, including SQL execution, advanced database management, and intelligent O&M, help you manage databases easily, securely, and intelligently.

By default, DAS connection permissions are enabled for DDS instances.

  • Easy to use, secure, advanced, and intelligent
  • Recommended

Connection over a private network

Private IP address

A private IP address is provided by default.

If your applications are running on an ECS in the same region and VPC as your DDS instance, connect to the DDS instance through the private IP address.

  • Secure and high-performance
  • For faster transmission and enhanced security, you are advised to migrate your applications to an ECS in the same VPC subnet as your DDS instance and connect to the instance through a private network.

Connection over a public network

EIP

  • If your application is running on an ECS that is in a different region from the one where your DB instance is located, connect to the instance using an EIP.
  • If you use a third-party device or your local device to connect to a DDS instance, connect to the DB instance using an EIP.
  • Less secure
  • For faster transmission and enhanced security, you are advised to migrate your applications to an ECS in the same VPC subnet as your DDS instance and connect to the instance through a private network.
  • An EIP must be purchased. For details, see EIP Pricing Details.
  • A public NAT gateway must be purchased. For details, see NAT Gateway Pricing Details.