ApsaraDB RDS:Change instance specifications

Configuration items

You can create read-only RDS instances to offload read requests from a primary RDS instance in your database system. This way, the read capability of your database system is increased. For more information, see Overview of read-only ApsaraDB RDS for PostgreSQL instances and Create a read-only ApsaraDB RDS for PostgreSQL instance.

Billing rules

For more information, see Specification change fees.

Usage notes

• If your RDS instance runs RDS Basic Edition, no secondary RDS instance is provided as 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 a specification change varies based on the configuration items that you want to change. For more information, see the Impact column in the "Configuration items" section of Change the specifications of an ApsaraDB RDS for PostgreSQL instance.

• When you change the specifications of your RDS instance, a transient connection or instance restart may occur during the workload switchover. 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 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 the "Configuration items" section of Change the specifications of an ApsaraDB RDS for PostgreSQL instance.

• After you change the specifications of your RDS instance, the ID and endpoints of the RDS instance remain unchanged.

• After you change the specifications of your RDS instance, you do not need to manually restart the instance.

• If a read-only RDS instance is attached to your primary RDS instance and you want to expand the storage capacity, make sure that the storage capacity of the read-only RDS instance is greater than or equal to that of the primary RDS instance. Otherwise, the storage capacity cannot be expanded. In this case, we recommend that you expand the storage capacity of the read-only RDS instance before you expand the storage capacity of the primary RDS instance.

• If read-only RDS instances are attached to your primary RDS instance and you want to change the storage capacity, make sure that the storage capacity of each read-only RDS instance is greater than or equal to that of the primary RDS instance. We recommend that you change the storage capacity based on the following description:

  • Storage capacity expansion: You must first expand the storage capacity of the read-only RDS instances. After the storage capacity of all read-only RDS instances is expanded, you can expand the storage capacity of the primary RDS instance.

  • Storage capacity reduction: You must first reduce the storage capacity of the primary RDS instance. After the storage capacity of the primary RDS instance is reduced, you can reduce the storage capacity of the read-only RDS instances.

• If read-only RDS instances that use local disks are attached to your primary RDS instance and you want to change the instance specifications, make sure that the specifications of each read-only RDS instance are greater than or equal to the specifications of the primary RDS instance. If read-only RDS instances that use cloud disks are attached to your primary RDS instance and you want to change the instance specifications, make sure that the specifications of each read-only RDS instance are greater than or equal to half the specifications of the primary RDS instance. We recommend that you change the instance specifications based on the following description:

  • Instance specification upgrade: You must first upgrade the specifications of the read-only RDS instances. After the specifications of all read-only RDS instances are upgraded, you can upgrade the specifications of the primary RDS instance.

  • Instance specification downgrade: You must first downgrade the specifications of the primary RDS instance. After the specifications of the primary RDS instance are downgraded, you can downgrade the specifications of the read-only RDS instances.

• When you upgrade the instance type of your RDS instance, make sure that the vSwitch to which the RDS instance is connected has at least two available IP addresses. If the vSwitch does not have sufficient available IP addresses, the instance type upgrade fails. You can log on to the Virtual Private Cloud (VPC) console to check the number of available IP addresses of the vSwitch. If the vSwitch does not have sufficient available IP addresses, switch your RDS instance to a different vSwitch that can provide sufficient available IP addresses before you upgrade the instance type. For more information, see Change the vSwitch.

Procedure

1. Go to the Instances page. In the top navigation bar, select the region in which the RDS instance resides. Then, find the RDS instance and click the ID of the 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 and click Next step. This step is required only for subscription RDS instances.

   Upgrade or Downgrade: After you submit a specification change order, the new specifications immediately take effect. Both specification change methods are supported for subscription RDS instances and pay-as-you-go RDS instances.

   After you submit a specification change order, the system synchronizes the data of the RDS instance from the disk to a new RDS instance. Then, the system switches the information, such as the ID and endpoints, about the RDS instance over to the new RDS instance based on the specification change method that you select.

   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 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 configuration items whose settings can be changed, see Change the specifications of an ApsaraDB RDS for PostgreSQL instance.

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, the system 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 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, the workloads are switched 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 cloud disks and you only expand the storage capacity or change the ESSD storage type between different PLs, your workloads are not affected. The system immediately switch over your workloads. In this case, you do not need to select Switch Within Maintenance Window.

   • If your RDS instance uses local disks, we recommend that you select Switch Within Maintenance Window. If the host on which your RDS instance resides can provide sufficient storage resources for storage capacity expansion, the system immediately switch over your workloads, and your workloads are not affected. If the host on which your RDS instance resides cannot provide sufficient storage resources for storage capacity expansion, the system migrates the data of your RDS instance to a new RDS instance. After the migration is complete, the system switches over your workloads to the new RDS instance during the 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. Therefore, 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.

FAQs

• How do I change the storage type of my RDS instance from cloud disk to local disk?

  For more information, see How do I change the storage type of an ApsaraDB RDS instance from cloud disk to local disk?

• 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 cloud disks, you do not need to migrate the data of the RDS instance to a new RDS instance.

  • If your RDS instance uses local disks, you must check storage resources of the host on which your RDS instance resides.

    • If the host can provide sufficient storage resources, you do not need to migrate the data.

    • If the host cannot provide sufficient storage resources, you need to migrate the data to another host that can provide sufficient storage resources.

• How do I reduce the storage capacity of my RDS instance?

  • If your RDS instance uses local disks, we recommend that you use the major version upgrade feature to upgrade the RDS instance to an instance that runs a later database engine version and uses cloud disks. You can reduce the storage capacity of your RDS instance when you upgrade the major engine version. For more information, see Upgrade the major version.

  • If your RDS instance uses cloud disks, follow the instructions provided in Reduce the storage capacity of an ApsaraDB RDS for PostgreSQL instance that uses ESSDs to reduce the storage capacity.

• 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 Configuration items.

Related operations