Different types of ApsaraDB for RDS instances are provided: common instances, dedicated instances, and dedicated-host instances. To distinguish from the instance type provided before January 2017, which we defined as common instances, the new instance types are defined as dedicated instances, among which dedicated-host instances have top-level configurations. A dedicated-host instance can be upgrade to the top level so that it can use a full physical machine.

The following list shows the features and applicable scenarios of various instance types:

Types Description Applicable scenarios
Common instances
  • It is a highly cost-effective instance type which maximizes utilization by reusing resources and allows you to enjoy the benefits of scale.
  • Its storage capacity is not subject to CPU/memory, allowing flexible configurations.
  • Price-sensitive customers
  • Scenarios where high-performance stability is not required
Dedicated instances/dedicated-host instances
  • The two types are new RDS instance types which feature fixed computing capabilities, storage space, and IO performance. 
  • A number of fully dedicated CPU cores and threads are assigned to each instance to ensure long-term stability in computing performance. 
  • The fixed storage space is reserved for higher stability. 
  • Dedicated-host instances are dedicated instances with top-level configurations.
It is applicable for business scenarios where a database-centric system is used, such as finance, e-commerce, government, medium and large -size Internet businesses.

The differences between common and dedicated instances are shown in the following figure.