This topic describes how to change the specifications of an ApsaraDB RDS for PostgreSQL instance. These specifications include the instance type and the storage capacity.

Prerequisites

Your Alibaba Cloud account does not have overdue renewal orders.

Change items

You can increase the read capability of your database system by creating read-only RDS instances. The read-only RDS instances are used to offload read requests from the primary RDS instance. For more information, see Overview of read-only ApsaraDB RDS for PostgreSQL instances and Create a read-only ApsaraDB RDS for PostgreSQL instance.

Change item Description
Instance type

You can change the instance type of your RDS instance regardless of the instance configuration.
Storage capacity

You can increase the storage capacity of your RDS instance regardless of the instance configuration.

If your RDS instance uses the subscription billing method and local SSDs, you can decrease the storage capacity only when you select the change upon renewal method. For more information, see Subscription renewal.

Note
  • The new storage capacity that you specify must be within the storage capacity range that is supported for the instance type. For more information, see Primary instance types.
  • If your RDS instance uses standard or enhanced SSDs, you cannot decrease the storage capacity.
  • If the storage capacity range that is supported for the instance type does not meet your business requirements, we recommend that you change the instance type.
Note After you change the preceding specifications of your RDS instance, the endpoints of the instance remain unchanged.

Billing

For more information, see Specification change fees.

Precautions

  • If you are using the Basic Edition, your RDS instance does not have a secondary RDS instance as a hot standby. If your RDS instance exits unexpectedly, your database service becomes unavailable. If you change the specifications or upgrade the database engine version of your RDS instance, your database service also becomes unavailable. The unavailability may last for a long period of time. If you require high service availability, we recommend that you do not use the Basic Edition.
  • When you change the specifications of your RDS instance, a data migration may be triggered. After the migration is complete, ApsaraDB RDS switches over your workloads during the specified switching time. The switchover does not interrupt the synchronization of incremental data. However, the switchover causes a transient connection error for about 30 seconds. In addition, the switchover interrupts most of the operations that are related to databases, accounts, and network settings. We recommend that you change the specifications during off-peak hours. Alternatively, make sure that your application is configured to automatically reconnect to your RDS instance.
  • After you change the specifications of your RDS instance, you do not need to manually restart the instance.
  • After you change the specifications of your RDS instance, the ID and endpoints of the instance remain unchanged.

Procedure

  1. Go to the Basic Information page.
    1. Log on to the ApsaraDB for RDS console. In the left-side navigation pane, click Instances. In the top navigation bar, select the region where your RDS instance resides.
      选择地域
    2. Find your RDS instance and click its ID.
  2. In the Configuration Information section of the Basic Information page, click Change Specifications.
  3. In the dialog box that appears, select a change method and click Next. This step is required only when your RDS instance uses the subscription billing method.
    Note You can select the Upgrade or Downgrade option for both subscription and pay-as-you-go RDS instances. The new specifications immediately take effect.
  4. Change the specifications of your RDS instance. For more information, see the "Change items" section of this topic.
  5. Set the Switching Time parameter.
    • Switch Immediately After Data Migration: The specification change causes a data migration. If you select this option, ApsaraDB RDS immediately applies the specification change and switches over your workloads after the migration is complete.
    • Switch Within Maintenance Window: When the specification change is being applied, a transient connection error of about 30 seconds may occur. This error interrupts most of the operations that are related to databases, accounts, and network settings. If you select this option, ApsaraDB RDS applies the specification change during the specified maintenance window. For more information, see Set the maintenance window of an ApsaraDB RDS for PostgreSQL instance.
  6. Read and select Terms of Service, click Pay Now, and then complete the payment.

FAQ

  1. How do I switch my RDS instance among the local, standard, and enhanced SSD storage types?

    For more information, see How to change a cloud disk to a local disk.

  2. If I only increase the storage capacity of my RDS instance, do I need to migrate data to a new RDS instance?

    Check whether the host where your RDS instance resides can provide sufficient storage space. If yes, ApsaraDB RDS increases the storage capacity without migrating data. If no, ApsaraDB RDS migrates data to a host that provides sufficient storage space.

Related operations

Operation Description
ModifyDBInstanceSpec Changes the specifications of an ApsaraDB RDS instance.