This topic describes the instance families of ApsaraDB RDS. ApsaraDB RDS supports the shared instance family, general-purpose instance family, and dedicated instance family.
Shared instance family
General-purpose instance family
You do not require high stability for your databases.
Dedicated instance family
Your databases are used as core systems in sectors such as finance, e-commerce, public services, and large and medium-sized Internet services.
For more information about the supported instance types and their specifications, such as the number of CPU cores, memory capacity, storage capacity, maximum number of connections, and input/output operations per second (IOPS), see Primary ApsaraDB RDS instance types.
For more information about the prices of different instance types, visit the ApsaraDB RDS buy page.
Instance family change
You can change the instance type of your RDS instance to an instance type that belongs to a different instance family based on your business requirements.
You cannot change the instance type of your RDS instance from a shared instance type to an instance type that belongs to a different instance family. If you want to switch from the shared instance family to a different instance family, you can create an RDS instance that uses the new instance type and then use Data Transmission Service (DTS) to migrate the data of your RDS instance to the new RDS instance. For more information, see Overview of data migration methods.
For more information about how to change the instance type of your RDS instance, see the following topics:
It seems that general-purpose instances outperform dedicated instances that have the same CPU cores and memory specifications. Why should I choose the dedicated instance family?
A dedicated RDS instance enjoys dedicated CPU and memory resources, whereas a general-purpose RDS instance enjoys only dedicated memory resources. Therefore, the dedicated instance offers more reliable performance in actual practice. For more information, see Instance families.