You can change the cluster specifications to meet your business requirements.


You can change cluster specifications only when the cluster does not have pending specification changes.

Background information

PolarDB supports capacity scaling in three dimensions:

  • Scale up or down the computing capacity: Upgrade or downgrade the specifications of the cluster. This method is detailed in the following sections.
  • Scale in or out computing capacity: Add or remove read-only nodes. For more information, see Add or remove a read-only node.
  • Scale in or out storage capacity: The storage capacity is provisioned in a serverless model. As your data increases in size, the storage is automatically expanded.

This topic describes how to upgrade or downgrade the specifications of a PolarDB cluster. It takes only 5 to 10 minutes for the new specifications of each node to take effect.

Configuration change fees

For more information, see Configuration change fees.


  • You can upgrade or downgrade only clusters. You cannot upgrade or downgrade a single node in a cluster.
  • When you upgrade or downgrade a cluster, data stored in the cluster is not affected.
  • We recommend that you modify cluster specifications during off-peak hours. During a specification upgrade or downgrade, the PolarDB service will be disconnected for a few seconds and some features will be disabled. You must reconnect to PolarDB from your application after the transient connection errors occur.


  1. Log on to the PolarDB console.
  2. In the upper-left corner of the console, select the region in which the cluster that you want to manage is deployed.
  3. Go to the Change Configurations page. You can use the following methods to change the specifications:
    • Find the cluster and click Change Configurations in the Actions column. Cluster list
    • Find the cluster, click the cluster ID, and then click Change Configurations in the Database Nodes section. Change specifications
  4. In the dialog box that appears, select Upgrade or Downgrade, and click OK.
    Change Configurations
  5. Select specifications.
    Note All nodes in a cluster use the same specifications.
  6. Read and select Terms of Service, click Pay Now, and then complete the payment.
    Note The new specifications take effect within 10 minutes.

Related API operations

Operation Description
ModifyDBNodeClass Changes the node specifications of a PolarDB cluster.