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

Prerequisites

Your Alibaba Cloud account does not have overdue renewal orders.

Change items

You can create read-only RDS instances to increase the read capability of your database system. The read-only RDS instances can offload queries 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 items Description
Storage type Storage performance varies based on the storage type and the performance level (PL) in ascending order: standard SSDs, enhanced SSDs (ESSDs) of PL1, ESSDs of PL2, and ESSDs of PL3.

If your RDS instance runs the RDS High-availability Edition with standard SSDs or ESSDs, you can upgrade the storage type. However, you cannot downgrade the storage type.

Note If your RDS instance runs the RDS Basic Edition with standard SSDs or ESSDs, you must upgrade the RDS edition of the instance to the High-availability Edition before you can upgrade the storage type of the instance. For more information, see Upgrade an ApsaraDB RDS for PostgreSQL instance from Basic Edition to High-availability Edition.
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.
Note
  • The new storage capacity that you specify for your RDS instance must be within the storage capacity range that is supported by the instance type of the instance. For more information, see Primary ApsaraDB RDS instance types.
  • You cannot decrease the storage capacity of the RDS PostgreSQL instance.
  • If the storage capacity range that is supported by the instance type of your RDS instance does not meet your business requirements, we recommend that you change the instance type of the instance.
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 your RDS instance runs the RDS Basic Edition, no secondary RDS instance is provided as a hot standby. In this case, if your RDS instance unexpectedly exits, your database service may be unavailable for a long period of time. If you change the specifications or upgrade the database engine version of your RDS instance, your database service may also be unavailable for a long period of time. If you have high requirements for service availability, we recommend that you do not use the RDS Basic Edition.
  • When you change the specifications of your RDS instance, ApsaraDB RDS may migrate the data of your original RDS instance to a new RDS instance. After the migration process is complete, ApsaraDB RDS switches your workloads over to the new RDS instance during the specified switchover time. During the switchover, your original RDS instance keeps synchronizing its incremental data to the new RDS instance. The switchover causes a transient connection that lasts approximately 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 of your RDS instance 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. Visit the RDS instance list, select a region above, and click the target instance ID.
  2. In the Configuration Information section of the page, click Change Specifications.
  3. In the dialog box that appears, select a change method and click Next step. This step is required only when your RDS instance uses the subscription billing method.
    Note You can select one of the following change methods:

    Upgrade or Downgrade

    The new specifications immediately take effect after you make the change. The two methods are supported for both subscription and pay-as-you-go RDS instances.

    After you start the specification change task, ApsaraDB RDS replicates the data of your RDS from the disk to a new RDS instance. Then, ApsaraDB RDS replicates other information about your RDS instance to the new RDS instance based on the change method that you select. This information includes the ID and endpoints of your RDS instance.

  4. Change the specifications of the RDS instance. For more information, see Change items.
  5. Specify the Switching Time parameter.
    • Switch Immediately After Data Migration: The specification change triggers a data migration to a new RDS instance. If you select this option, ApsaraDB RDS immediately applies the specification change and switches your workloads over to the new RDS instance after the migration process is complete.
    • Switch Within Maintenance Window: When the specification change is being applied, a transient connection that lasts approximately 30 seconds may occur. The transient connection 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.
    Warning After you submit a specification change order, do not perform data definition language (DDL) operations before the specification change is applied.

FAQ

  1. How do I change the storage type of my RDS instance from standard SSDs or ESSDs to local SSDs?

    For more information, see How do I migrate an ApsaraDB RDS instance from standard or enhanced SSDs to local SSDs?.

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

    This depends on whether the host on which your RDS instance resides can provide sufficient storage space. If the host can provide sufficient storage space, ApsaraDB RDS increases the storage capacity without a data migration. Otherwise, ApsaraDB RDS migrates the data to a host that provides sufficient storage space.

Related operations

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