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    ApsaraDB RDS:Change configurations

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    ApsaraDB RDS:Change configurations

    Last Updated:Jul 29, 2025

    This topic describes how to change the configurations of an ApsaraDB RDS for PostgreSQL instance, such as the instance edition, instance type, and storage capacity.

    Prerequisites

    • The instance uses the subscription or pay-as-you-go billing method.

      Note

      If your instance uses the serverless billing method, see Serverless instances to change its configurations.

    • The instance is in the Running state.

    • Your Alibaba Cloud account has no unpaid renewal orders.

    Configuration items

    If you want to scale out the read capability of your database, you can create read-only instances to offload the workload from the primary instance. For more information, see Introduction to ApsaraDB RDS for PostgreSQL read-only instances and Create an ApsaraDB RDS for PostgreSQL read-only instance.

    Warning

    Depending on the configuration items that you want to change, a transient connection may occur or the instance may be restarted. During the configuration change, you cannot perform most operations related to databases, accounts, or networks. We recommend that you change the configurations of your instance within the specified maintenance window.

    Configuration item

    Description

    Impacts on your services

    Series

    The following changes are supported:

    A transient connection occurs.

    Product type

    You can change the product type between Standard Edition and Yitian Edition. For more information about the differences between Standard Edition and Yitian Edition, see Product types.

    Note

    • If you cannot select the destination product type, the resources for that product type may be sold out in the zone where the instance resides.

      You can go to the instance purchase page to check the zones in which the destination product type is available. Then, you can use the Migrate Across Zones feature to migrate the instance to a destination zone before changing the product type.

    • If you want to change the product type of an instance, make sure that the minor engine version of the instance after the change is the same as or later than the current minor engine version. If the current minor engine version is later than the minor engine version after the change, you cannot change the product type.

    • Instance types of Yitian Edition do not support the plv8 or rdkit plug-ins. If you want to change the product type from Standard Edition to Yitian Edition, make sure that these plug-ins are not in use. For more information about the plug-ins supported by each product type, see Supported plug-ins.

    A transient connection occurs.

    Storage type

    You can change the storage type.

    • Instances that use cloud disks:

      • You can upgrade the storage type from standard SSD to ESSD (PL1 ESSD, PL2 ESSD, or PL3 ESSD). You cannot downgrade the storage type from ESSD to standard SSD.

      • You can upgrade or downgrade the storage type among PL1 ESSD, PL2 ESSD, and PL3 ESSD.

      • You can change the storage type from ESSD to premium performance disk. You cannot change the storage type from premium performance disk to ESSD.

    • Instances that use local disks: You cannot change the storage type of instances that use local disks.

    Note

    For more information about the performance of different storage types, see Storage types.

    • If you upgrade or downgrade the storage type among PL1 ESSD, PL2 ESSD, and PL3 ESSD, no transient connection occurs.

      If you change the storage type from ESSD to premium performance disk, no transient connection occurs.

    • If you upgrade the storage type from standard SSD to ESSD, a transient connection occurs.

    Instance type

    You can change the instance type.

    Note

    • If you upgrade the instance type, a transient connection occurs.

    • If you downgrade the instance type, the primary database of the instance is restarted. After the restart, a transient connection occurs.

    • During the instance type change, some kernel parameters of the read-only instance must be the same as those of the primary instance. As a result, the read-only instance is restarted, which causes a transient connection.

    Storage capacity

    You can scale out or scale in the storage capacity.

    • Scale out storage capacity: You can increase the storage capacity in increments of 5 GB. The storage capacity cannot exceed the upper limit specified for the current instance type. For more information, see Primary ApsaraDB RDS for PostgreSQL instance types.

    • Scale in storage capacity: For an instance that uses cloud disks, you can scale in the storage capacity within the same instance edition and architecture. The minimum storage capacity after the scale-in is calculated using the following formula: min{Used storage × 1.3, Used storage + 400 GB}. The storage capacity cannot be smaller than the minimum storage capacity allowed for the current instance type. The storage capacity can be adjusted in increments of 5 GB. For more information, see Scale in the storage capacity of an ApsaraDB RDS for PostgreSQL instance that uses ESSDs.

      Example of scaling in storage capacity

      Assume that an instance uses a PL1 ESSD that provides a minimum storage capacity of 20 GB and the total storage capacity is 2,000 GB.

      • If 10 GB of storage is used, the calculated value is 13 GB, which is smaller than 20 GB. The storage capacity can be scaled in to a minimum of 20 GB.

      • If 500 GB of storage is used, the calculated value is 650 GB. The storage capacity can be scaled in to a minimum of 650 GB.

      • If 1,500 GB of storage is used, the calculated value is 1,900 GB. The storage capacity can be scaled in to a minimum of 1,900 GB.

    Note

    • If your RDS instance uses local disks, we recommend that you use the major engine version upgrade feature to upgrade the instance to a later major engine version that uses cloud disks. You can scale in the storage capacity during the upgrade. For more information, see Upgrade the major engine version of an ApsaraDB RDS for PostgreSQL instance.

    • If your instance that uses cloud disks was created before October 10, 2022 (on an old architecture), you must upgrade the minor engine version to the latest version before you can scale in the storage capacity. For more information, see Update the minor engine version of an ApsaraDB RDS for PostgreSQL instance.

    • For an instance that uses cloud disks, you can manually adjust the storage capacity by changing configurations or configure automatic storage expansion. When the percentage of remaining storage of the instance reaches the specified threshold, automatic storage expansion is triggered to ensure service stability.

    • If a backup is in progress for the instance, the scale-out task starts after the backup is complete. We recommend that you scale out the storage capacity of the instance outside the backup time.

    • Cloud disks:

      • If you scale out the storage capacity, no transient connection occurs.

      • If you scale in the storage capacity, a transient connection occurs.

    • Local disks: A transient connection occurs.

    Billing rules

    For more information, see Specification change fees.

    Precautions

    • Basic Edition instances have only one database node and do not have a secondary node for hot backup. Therefore, if the node encounters unexpected downtime or you perform tasks such as changing configurations or upgrading the major engine version, the instance may be unavailable for an extended period. If your services require high database availability, we recommend that you do not use Basic Edition instances. You can select other instance editions, such as High-availability Edition.

      Note

      Whether a transient connection occurs depends on the configuration items that you change. For more information, see the Impacts on your services column in the Configuration items section.

    • Depending on the configuration items that you want to change, a transient connection may occur or the instance may be restarted. During the configuration change, you cannot perform most operations related to databases, accounts, or networks. We recommend that you change the configurations of your instance within the specified maintenance window. For more information about the impacts of each configuration change on your services, see the Impacts on your services column in the Configuration items section.

    • The instance ID and endpoint remain unchanged after you change the configurations.

    • You do not need to manually restart the instance after you change the configurations.

    • If the primary instance has read-only instances, make sure that the storage capacity of each read-only instance is greater than or equal to the storage capacity of the primary instance when you change the storage capacity. We recommend that you perform the following operations:

      • When you scale out the storage capacity, first scale out the storage capacity of the read-only instances. After the storage capacity of all read-only instances is scaled out, you can scale out the storage capacity of the primary instance.

      • When you scale in the storage capacity, first scale in the storage capacity of the primary instance. After the storage capacity of the primary instance is scaled in, you can scale in the storage capacity of the read-only instances.

    • If the primary instance has read-only instances, make sure that the instance type of each read-only instance that uses local disks is greater than or equal to the instance type of the primary instance and that the instance type of each read-only instance that uses cloud disks is greater than or equal to half of the instance type of the primary instance when you change the instance type. We recommend that you perform the following operations:

      • When you upgrade the instance type, first upgrade the instance types of the read-only instances. After the instance types of all read-only instances are upgraded, you can upgrade the instance type of the primary instance.

      • When you downgrade the instance type, first downgrade the instance type of the primary instance. After the instance type of the primary instance is downgraded, you can downgrade the instance types of the read-only instances.

    • When you upgrade the instance type, you must make sure that the vSwitch to which the instance is connected has at least two available IP addresses. Otherwise, the upgrade fails. You can go to the VPC console to view the number of available IP addresses in the destination vSwitch. If the number of available IP addresses in the vSwitch is insufficient, you can switch to a vSwitch that has sufficient IP addresses and then upgrade the instance type. For more information, see Change the vSwitch and VPC of an ApsaraDB RDS for PostgreSQL instance.

    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 area, click Change Specifications.

    3. (This step is required only for subscription instances.) In the dialog box that appears, select a change method and click Next.

      Upgrade or Downgrade: The new configuration takes effect immediately. This method is supported for both subscription and pay-as-you-go instances.

      After you submit the change task, the system synchronizes the disk data to a new instance. Then, the system switches the instance ID and endpoint of the original instance to the new instance at the time specified by Immediate Upgrade or Immediate Downgrade. The instance ID and endpoint remain unchanged.

      Warning

      If you select Downgrade, the primary instance restarts during the switchover. We recommend that you perform the specification change within the maintenance window.

    4. Modify the configurations of the instance. For more information about the modifiable configuration items, see Configuration items.

    5. Select an execution time for the configuration change.

      • Execute Immediately: An instance configuration change involves an underlying data migration. You can choose to switch immediately after the data migration is complete.

      • Switch Within Maintenance Window: While the configuration change is being applied, service transient connections or instance restarts may occur. In addition, most operations related to databases, accounts, or networks cannot be performed. Therefore, you can choose to perform the switchover within the maintenance window.

      Note

      • For instances that use cloud disks: if you only increase the storage space or change the ESSD storage class, your services are not affected, the configuration change takes effect immediately, and you do not need to select Switch Within Maintenance Window.

      • Instances that use high-performance local disks: We recommend that you select Switch Within Maintenance Window. If the host on which the instance resides has sufficient storage space for the expansion, the upgrade is performed immediately and does not affect your services. If the host has insufficient storage space, a data migration is triggered. After the migration is complete, a switchover is performed at your specified time. Incremental synchronization is performed during the switchover.

    6. On the Change Specifications page, confirm the instance information before and after the upgrade or downgrade. Read the Terms of Service, click Confirm Order, and complete the payment.

      Warning

      • After you submit the order for the configuration change, you cannot cancel the order. Before you change the configurations, carefully evaluate your business requirements.

      • To ensure the stability of the configuration change, do not perform Data Definition Language (DDL) operations from the time you submit the order to the time the configuration change is complete.

    FAQ

    • Q: How do I change the storage type of an instance from cloud disk to local disk?

      A: For more information, see How do I change the storage type from cloud disk to local disk?.

    • Q: If I only scale out the storage capacity, do I need to migrate data to a new instance?

      A:

      • Instances that use cloud disks: No.

      • Instances that use local disks: You need to check whether the host on which the instance resides has sufficient storage capacity for the scale-out.

        • If the storage capacity is sufficient, the storage capacity is directly scaled out. You do not need to migrate data.

        • If the storage capacity is insufficient, you need to migrate data to a host that has sufficient storage capacity.

    • Q: How do I scale in the storage capacity?

      A:

    • Q: If I upgrade the CPU, memory, and disk at the same time, how long does the transient connection last?

      A: The duration of the transient connection is the same regardless of whether you upgrade only one of the CPU, memory, and disk or all three at the same time. The duration is typically a few minutes. During the switchover, a transient connection may occur or the instance may be restarted. In addition, you cannot perform most operations related to databases, accounts, or networks. We recommend that you change the configurations within the specified maintenance window. For more information about the impacts of each configuration change on your services, see Impacts on your services for each configuration item.

    • Q: Does changing only the configurations of a read-only instance affect the primary instance?

      A: Changing only the configurations of a read-only instance usually does not affect the primary instance. However, a specific association with the primary instance must be maintained. For more information, see the Precautions section of this topic.

    Related API

    API

    Description

    ModifyDBInstanceSpec

    Changes the specifications of an ApsaraDB RDS instance.