A TencentDB instance is a standalone database environment running in Tencent Cloud. It includes multiple databases created by users 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||Feature|
|Source instance||An instance that can be read from and written to||Yes||A source 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 source instance. Its data comes solely from syncing with the source instance, and it must reside in the same region as the source instance.|
|Disaster recovery instance||An instance that supports disaster recovery across AZs and regions||Yes||A disaster recovery instance is read-only when it syncs with a source instance. It can actively stop the sync and be promoted to a source instance for read/write access. The disaster recovery instance should reside in a different region than the source instance does.|