Basic Concepts

Before using GaussDB(for MySQL), you should be familiar with the following concepts.

Primary/Standby Instances

GaussDB(for MySQL) uses a decoupled compute and storage architecture that auto-scales up to 128 TB per DB instance. A primary/standby DB instance contains a primary node and up to 15 read replicas which can be created in minutes.

Single-Node Instances

A single-node instance contains only one primary node and there are no read replicas. Single-node instances do not involve data synchronization between nodes and can easily ensure atomicity, consistency, isolation, and durability of transactions. Single-node instances lack high availability assurance. If a fault occurs, the fault cannot be rectified in a timely manner.

Instance Specifications

Each instance is configured with compute and memory resources, for example, 16 vCPUs and 64 GB.

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 can be universal or dedicated. A universal region provides all sorts of cloud services for all users. A dedicated region provides only services of a given 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 an AZ as needed. For more information, see Global Products and Services.