A database instance is a standalone database environment running in Tencent Cloud. It can contain multiple user-created databases and can be accessed using the same tools and applications as those for a standalone database instance. There are three types of instances available in TencentDB for MySQL.
| Instance Type | Definition | Architecture | Visible in the Instance List | Function |
|---|---|---|---|---|
| Master instance | An instance that can be read from and written to | Basic edition and High availability edition | Yes | A master instance can mount read-only instances and disaster recovery instances for read/write separation and remote disaster recovery |
| Read-only instance | An instance that can only be read from | Single-node high-IO edition | Yes | A read-only instance cannot exist on its own; instead, it must be affiliated to a master instance. Its data comes solely from sync with the master instance. Besides, it must reside in the same region as the master instance |
| Disaster recovery instance | An instance that enables disaster recovery across AZs and regions | High availability edition | Yes | A disaster recovery instance is read-only during sync with a master instance. It can actively stop the sync and be promoted to a master instance for read/write access. It must reside in a different region as the master instance |
