Basic Concepts

DB Instances

The smallest management unit of RDS is the DB instance. A DB instance is an isolated database environment on the cloud. Each DB instance runs a DB engine. For details about DB instance types, specifications, engines, versions, and statuses, see DB Instance Description.

DB Engines

RDS supports the following DB engines:

• MySQL
• PostgreSQL
• Microsoft SQL Server
• MariaDB

For details about the supported versions, see DB Engines and Versions.

DB Instance Types

There are two types of RDS DB instances: single and primary/standby. Different series support different DB engines and instance specifications.

For details about DB instance types, see DB Instance Introduction and Function Comparison.

DB Instance Classes

The DB instance class determines the compute (vCPUs) and memory capacity (memory size) of a DB instance. For details, see DB Instance Classes.

Automated Backups

When you create a DB instance, an automated backup policy is enabled by default, but after the DB instance is created, you can modify the policy if needed. RDS will automatically create full backups for DB instances based on your settings.

Manual Backups

Manual backups are user-initiated full backups of DB instances. They are retained until you delete them manually.

Regions and AZs

A region and availability zone (AZ) identify the location of a data center. You can create resources in a specific region and AZ.

• Regions are defined by their geographical location and network latency. Public services, such as Elastic Cloud Server (ECS), Elastic Volume Service (EVS), Object Storage Service (OBS), Virtual Private Cloud (VPC), Elastic IP (EIP), and Image Management Service (IMS), can all be shared within a given region. Regions are classified as universal regions and dedicated regions. A universal region provides cloud services for all users. A dedicated region provides services of only a specific type or only for specific users.
• An AZ contains one or multiple physical data centers. Each AZ has its own independent cooling, fire extinguishing, moisture-proofing, and electrical facilities. Within an AZ, compute, network, storage, and other resources are logically divided into multiple clusters. AZs within a region are interconnected using high-speed optical fibers so you can build cross-AZ high-availability systems.

Figure 1 shows the relationship between regions and AZs.

Figure 1 Regions and AZs

Huawei Cloud provides services in many regions around the world. You can select a region and AZ as needed. For more information, see Global Products and Services.

Projects

Projects are used to group and isolate OpenStack resources (compute, storage, and network resources). A project can be a department or a project team. Multiple projects can be created for a single account.