ApsaraDB RDS:Change the specifications of an ApsaraDB RDS for PostgreSQL instance

Configuration 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.

Billing

For more information, see Specification change fees.

Usage notes

• If your RDS instance runs 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 RDS Basic Edition.
  Note Whether a transient connection occurs during the specification changes varies based on the configuration items that you want to change. For more information, see the Impact column in Configuration items.
• When you change some specifications of your RDS instance, ApsaraDB RDS may migrate the data of your RDS instance to a new RDS instance. After the migration is complete, ApsaraDB RDS switches your workloads over to the new RDS instance. During the switchover, a transient connection or instance restart may occur. You cannot perform most of the operations that are related to databases, accounts, and network settings during the switchover. We recommend that you change the specifications of your RDS instance within the specified maintenance window. For more information, see Set the maintenance window of an ApsaraDB RDS for PostgreSQL instance. For more information about the impacts of configuration items, see the Impact column in Configuration items.
• After you change the specifications of your RDS instance, the ID and endpoints of the instance remain unchanged.
• After you change the specifications of your RDS instance, you do not need to manually restart the instance.

Procedure

1. Access RDS Instances, select a region at the top, and then click the ID of the target RDS instance.
2. In the Configuration Information section of the Basic Information page, click Change Specifications.
3. In the dialog box that appears, select a specification change method(Upgrade or Downgrade) and click Next step. This step is required only when the RDS instance uses the subscription billing method.

   After you submit a specification change order, ApsaraDB RDS synchronizes the data of the RDS instance from the disk to a new RDS instance. Then, ApsaraDB RDS switches the information, such as the instance ID and endpoints, about the RDS instance over to the new RDS instance based on the specified switching time.

   Warning If you select Downgrade, the primary RDS instance is restarted during the switchover. We recommend that you change the specifications of the RDS instance within the specified maintenance window. For more information, see Set the maintenance window of an ApsaraDB RDS for PostgreSQL instance.
4. Change the specifications of the RDS instance. For more information about the supported configuration items, see Configuration items.
5. Configure the Switching Time parameter.
   • Execute Immediately: 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 immediately after the migration process is complete.
   • Switch Within Maintenance Window: When the specification change is being applied, a transient connection or instance restart may occur and you cannot perform 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 maintenance window that you specify. For more information, see Set the maintenance window of an ApsaraDB RDS for PostgreSQL instance.

   Note

   • If your RDS instance uses standard SSDs or ESSDs and you only increase the storage capacity or only change the ESSD storage type between ESSD PL1, ESSD PL2, and ESSD PL3, your workloads are not adversely affected. ApsaraDB RDS immediately applies the specification change. In this case, you do not need to select Switch Within Maintenance Window.
   • If your RDS instance uses local SSDs, we recommend that you select Switch Within Maintenance Window. If the host in which your RDS instance resides provides sufficient storage resources for storage capacity expansion, the RDS instance is immediately upgraded, which does not adversely affect your workloads. If the host in which your RDS instance resides cannot provide sufficient storage resources for storage capacity expansion, ApsaraDB RDS migrates the data of your RDS instance to a new RDS instance. After the migration is complete, ApsaraDB RDS switches over your workloads to the new RDS instance during the specified maintenance window. Incremental synchronization is performed during the switchover.
6. Read and select Terms of Service and click Pay Now. In the dialog box that appears, confirm the instance information before and after the specification change and click Continue to complete the payment.
   Warning

   • After you submit a specification change order, you cannot cancel the order. Before you submit a specification change order, we recommend that you evaluate whether the new specifications meet your business requirements.
   • After you submit a specification change order, do not perform DDL operations before the specification change is applied.

FAQ

• How do I change the storage type of my RDS instance from standard SSD or ESSD to local SSD?

  For more information, see How do I change the storage type of an ApsaraDB RDS instance from standard SSD or ESSD to local SSD?

• If I want to expand only the storage capacity of my RDS instance, do I need to migrate the data of my RDS instance to a new RDS instance?
  • If your RDS instance uses standard SSDs or ESSDs, ApsaraDB RDS does not migrate the data of the RDS instance to a new RDS instance.
  • If your RDS instance uses local SSDs, ApsaraDB RDS determines whether to migrate the data of the RDS instance based on the storage resources on the host in which your RDS instance resides.
    • If the host provides sufficient storage resources, ApsaraDB RDS automatically increase the storage capacity without the need to migrate data.
    • If the host does not provide sufficient storage resources, ApsaraDB RDS migrates the data to another host that can provide sufficient storage resources.
• How do I reduce the storage capacity of my RDS instance?
  You cannot reduce the storage capacity of your RDS instance by changing the specifications of the instance.

  • If your RDS instance uses local SSDs, we recommend that you use the major version upgrade feature to upgrade the instance to an instance that runs a later database engine version and uses standard SSDs or ESSDs. You can reduce the storage capacity of your RDS instance when you upgrade the major engine version. For more information, see Upgrade the major engine version of an ApsaraDB RDS for PostgreSQL instance.
  • If your RDS instance uses standard SSDs or ESSDs, we recommend that you use the cloud migration feature to reduce the storage capacity of your RDS instance. For more information, see Scale down an ApsaraDB RDS for PostgreSQL instance.
• If I upgrade the CPU cores, memory, and storage capacity of an RDS instance at the same time, how long does a transient connection last?

  The transient connection lasts the same as the transient connection that occurs when you separately upgrade the CPU cores, memory, or storage capacity of an RDS instance. In most cases, the transient connection lasts for a few minutes. When the system switches your workloads, a transient connection may occur, or your RDS instance may be restarted. During the switchover, you cannot perform most of the operations that are related to databases, accounts, and network settings. We recommend that you change the specifications of your RDS instance within the specified maintenance window. For more information about the impacts of different configuration items, see the "Configuration items" section of this topic.

Related operations