Help Center> GaussDB(for MySQL)> Service Overview> Basic Concepts
Updated on 2023-09-14 GMT+08:00
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Basic Concepts

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

  • Primary/standby instances: GaussDB(for MySQL) has an architecture with decoupled storage and compute that auto-scales up to 128 TB per instance. A primary/standby instance can contain 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 of nodes and can easily ensure atomicity, consistency, isolation, and durability of transactions.
  • Regions are defined by a combination of 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), are shared within the same 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. Generally, GaussDB(for MySQL) instances and ECSs must be located in the same region for high access performance.
  • Availability zone (AZ): An AZ contains one or multiple physical data centers. Each AZ has independent cooling, fire extinguishing, moisture-proofing, and electricity facilities. Within an AZ, computing, network, storage, and other resources are logically divided into instances. An AZ is a geographic location with independent power supply and network facilities in a region.

    AZs are physically isolated but interconnected over an intranet. Each AZ provides cost-effective and low-latency network connections that are unaffected by faults in other AZs. As a result, provisioning GaussDB(for MySQL) instances in separate AZs protects your applications against local faults that occur in a single location. AZs within the same region have no functional differences.

  • Instance specifications: Each instance is configured with compute and memory resources, for example, 16 vCPUs and 64 GB.
  • Compatibility between GaussDB(for MySQL) and browsers: see Which Browsers Are Supported?