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


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

Background information

You can change the specifications of your cluster to meet business requirements. PolarDB supports capacity scaling in three dimensions:

  • Vertical scaling of computing power: You can upgrade or downgrade the specifications of a cluster. This topic describes the details.
  • Horizontal scaling of computing power: You can add or remove read-only nodes. For more information, see Add or remove a read-only node.
  • Horizontal scaling of storage capacity: The storage capacity is provisioned in a serverless model. The storage capacity is automatically scaled based on the amount of data.

Specification change fees

For more information, see Configuration change fees.


  • Specification upgrades or downgrades apply only to clusters. You cannot change the specifications of a single node.
  • Specification upgrades or downgrades of a cluster do not affect the existing data in the cluster.
  • During a specification upgrade or downgrade, transient connection errors occur in PolarDB services for a few seconds and some of the features are disabled. Therefore, we recommend that you change cluster specifications during off-peak periods. You must reconnect your applications to the PolarDB service after a transient connection error.


  1. Log on to the PolarDB console.
  2. In the upper-left corner of the console, select the region where your cluster is deployed.
  3. Go to the Change Configurations page by using one of the following two methods:
    • Find the cluster whose specifications you want to change, and click Change Configurations in the Actions column.Clusters
    • Click the ID of the cluster whose specifications you want to change. Then, in the Database Nodes section of the Overview page, click Change Configurations.Basic Information section
  4. Select Upgrade or Downgrade and click OK.Change configurations
    Note Only subscription clusters support Temporary Upgrade. For more information, see Perform a temporary upgrade.
  5. Select the desired specifications.
    Note All nodes in a cluster have the same specifications.
  6. Read and agree to the service agreement, select the check box, and then click Buy Now to complete the payment.
    Note It takes about 10 minutes for the new specifications to take effect.

Related API operations

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