Modify the configuration of an ApsaraDB RDS for PostgreSQL instance-ApsaraDB RDS(RDS)-阿里云帮助中心

This topic describes how to modify the configurations of an ApsaraDB RDS for PostgreSQL instance in the console. You can modify the edition, product type, storage type, instance type, storage capacity, minor engine version, parameters, and zone.

Prerequisites

The instance must use the subscription or pay-as-you-go billing method.

Note
You cannot modify Serverless instances.
The instance must be in the Running state.
Your Alibaba Cloud account has no unpaid renewal orders.

Modifiable items and their impacts

Warning

Depending on the item that you modify, a transient connection may occur or the instance may restart during the switchover. During this process, most operations related to databases, accounts, and networks are unavailable. We recommend that you make this change during your specified maintenance window.

Item	Description	Impact
Edition	You can upgrade an instance from Basic Edition to High-availability Edition, or from Basic or High-availability Edition to Cluster Edition.	A transient connection occurs.
Product type	You can switch the product type between Standard Edition and Yitian Edition. Note If you cannot select the target product type, the required resources may be unavailable in the current zone. You can check the instance purchase page for zones where the target product type is available, migrate your instance to a target zone, and then change the product type. When you change the product type, the new minor engine version must be the same as or later than the current version. Downgrading the version is not supported. Yitian Edition instances do not support the plv8 and rdkit extensions. Before you change the product type from Standard Edition to Yitian Edition, make sure that these extensions are not in use.	A transient connection occurs.
Storage type	You can change the storage type. For instances that use cloud disks: You can upgrade from standard SSD to ESSD (ESSD PL1, ESSD PL2, or ESSD PL3). You cannot downgrade from ESSD to standard SSD. You can upgrade or downgrade between ESSD PL1, ESSD PL2, and ESSD PL3. You can change the storage type from ESSD to general-purpose cloud disk. You cannot change the storage type from general-purpose cloud disk to ESSD. For instances with local SSDs, you cannot change the storage type.	No transient connection occurs when you upgrade or downgrade the storage type between ESSD PL1, ESSD PL2, and ESSD PL3. No transient connection occurs when you change the storage type from ESSD to general-purpose cloud disk. A transient connection occurs when you upgrade from standard SSD to ESSD.
Instance type	You can change the instance type. Note For High-availability Edition instances, you can change a general-purpose instance type to a dedicated instance type with 16 or more CPU cores. After you change a general-purpose instance type to a dedicated instance type, you can change it back to a general-purpose instance type.	Upgrading the instance type causes a transient connection. Downgrading the instance type causes the primary instance to restart, causing a transient connection.
Storage capacity	You can increase or decrease the storage capacity. To increase storage capacity: The capacity must be increased by at least 5 GB. The total storage capacity cannot exceed the limit for the current instance type. To decrease storage capacity: For instances that use cloud disks, you can decrease the storage if the edition and architecture remain unchanged. The new capacity is determined by the formula: `min(used storage * 1.3, used storage + 400 GB)`. The capacity cannot be smaller than the minimum allowed for the current instance type. You must decrease storage in 5 GB increments. Note If your RDS instance uses local SSDs, we recommend upgrading to a major version that supports cloud disks. This allows you to decrease the storage capacity during the upgrade process. For instances that use cloud disks, you can manually adjust the storage capacity by changing specifications or enable automatic storage expansion. With automatic expansion, the storage capacity is automatically increased when the percentage of available storage reaches a specified threshold. This helps prevent service disruptions from insufficient storage. If a backup is in progress, the storage expansion task starts only after the backup is complete. We recommend that you increase the storage capacity outside of the backup window.	Cloud disks: Increasing the storage capacity does not cause a transient connection. Decreasing the storage capacity causes a transient connection. Local SSDs: A transient connection occurs.
Minor engine version	You can upgrade the minor engine version of the instance.	A transient connection occurs.
Parameters	You can modify instance parameters. Some changes require a restart, while others take effect immediately.	Modifying a parameter that requires an instance restart causes a transient connection. Modifying a parameter that does not require an instance restart does not cause a transient connection.
Zone	You can change the zone and vSwitch of the instance.	A transient connection occurs.

Considerations

Basic Edition instances have only one database node and no secondary node for hot backup. This can lead to a long period of unavailability if the node unexpectedly fails or when you change specifications or upgrade the engine version. If your business requires high database availability, we recommend using other editions, such as High-availability Edition.

Note
Whether a specification change causes a transient connection depends on the item that you change. For more information, see the Impact column in Modifiable items and their impacts.
Depending on the item that you modify, a transient connection may occur or the instance may restart. During the modification, most operations related to databases, accounts, and networks are unavailable. We recommend making the change during the specified maintenance window. For more information about the impact of each modifiable item, see the Impact column in Modifiable items and their impacts.
Changing the instance configurations does not change the instance ID or endpoint.
A manual restart is not required after the configuration change.
If the target instance has read-only instances and you want to change the storage capacity, make sure that the storage capacity of each read-only instance is greater than or equal to that of the primary instance. We recommend that you perform the following steps:
- To increase the storage capacity, first increase the storage capacity of the read-only instances. After they are all upgraded, increase the capacity of the primary instance.
- To decrease the storage capacity, first decrease the storage capacity of the primary instance. After the primary instance is downgraded, decrease the storage capacity of the read-only instances.
If the target instance has read-only instances and you want to change the instance type, make sure that the instance type of read-only instances that use local SSDs is greater than or equal to that of the primary instance. For read-only instances that use cloud disks, make sure that their instance type is at least half of the instance type of the primary instance. We recommend that you perform the following steps:
- To upgrade the instance type, first upgrade the instance types of the read-only instances. After the instance type of all read-only instances is upgraded, upgrade the instance type of the primary instance.
- To downgrade the instance type, first downgrade the instance type of the primary instance. After the instance type of the primary instance is downgraded, downgrade the instance types of the read-only instances.
When you upgrade the instance type, ensure the vSwitch connected to the instance has at least two available IP addresses. Otherwise, the upgrade fails. You can check the number of available IP addresses for the target vSwitch in the VPC console. If the vSwitch does not have enough IP addresses, switch to a vSwitch with sufficient IP resources before you upgrade the instance type.

Procedure

Go to the Instances page. In the top navigation bar, select the instance's region, and then click the target instance's ID.
In the upper-right corner of the page, click Modify Instance.
(This step is required only for subscription instances.) In the Change Configurations dialog box, select a modification method and click Next.
- Standard Modification: Use for any modification that does not decrease the instance type or storage capacity. You can also keep the same instance type and change only the minor engine version, parameters, and other instance configurations.
- Downgrade: Reduce the instance type and storage capacity. You can also modify other configurations, such as the minor engine version and parameters.
Modify the instance configurations. For more information about the modifiable items, see Modifiable items and their impacts.
Select when to apply the configuration changes.
- Execute Immediately: The switchover to the new specifications occurs immediately after the data migration is complete.
- Switch Within Maintenance Window: You can schedule the switchover to occur during the specified maintenance window.
Note
- Instances that use cloud disks: If you only increase the storage capacity or change the ESSD storage type, there is no service interruption. The change is applied immediately. You do not need to select Switch Within Maintenance Window.
- Instances that use local SSDs: We recommend that you select Switch Within Maintenance Window. If the host where the instance is located has sufficient storage space for the expansion, the upgrade occurs immediately without service interruption. If the storage space is insufficient, data migration is triggered. After the migration is complete, the switchover occurs at your selected time. Incremental data is synchronized during the migration.
On the Upgrade Instance page, confirm the instance configurations before and after the modification, read the terms of service, and then click Pay Now to complete the payment.
Warning
- You cannot cancel a modification order after you submit it. Evaluate your business requirements before you proceed.
- To ensure a stable modification process, do not perform any DDL operations from the time you submit the order until the modification is complete.

Related APIs

API	Description
ModifyDBInstanceSpec	Change the instance type or storage capacity of an RDS instance.