Call the ModifyDBInstanceSpec API to modify instance configurations.

Request type

Asynchronous request.

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Request parameters

Parameter	Type	Required?	Example	Description
InstanceId	String	Yes	postgres-21a3333b****	Instance ID.
NodeInfo	Array of NodeInfoObject	No	Refer to the request example.	Instance specification configuration. There is exactly one primary node and one secondary node, with 0 to 10 optional read-only nodes. tip One of the parameters Storage space or this parameter must be selected, and both parameters can be modified simultaneously. Only the nodes involved in the specification modification need to be passed in this parameter.
ModifyType	String	No	Temporary	Modification method. Values are: Usually: regular modification of specification, which takes effect immediately. Default value. Temporary: elastic upgrade, that is, temporary upgrade. tip Only instances with the billing method of subscription support the parameter value Temporary. You can query the instance's billing method by calling the DescribeDBInstanceDetail API.
RollbackTime	String	No	2023-12-16T03:59:10.000Z	Restoration time. The time format is yyyy-MM-ddTHH:mm:ss.sssZ (UTC time). tip This parameter is required when ModifyType is Temporary. This parameter is effective only when ModifyType is Temporary. The set restoration time should not differ from the API call time by more than 2 minutes. The actual restoration time is based on the API call time. Temporary upgrades can be initiated multiple times to extend the temporary upgrade period, but the total duration cannot exceed 30 days (based on the time of the first temporary upgrade initiation). Multiple temporary upgrades can be initiated, but their duration cannot be shortened. If the instance is already in the temporary upgrade period: The new restoration date cannot be earlier than the effective restoration date. When the subscription instance is within five days of expiration, initiating another temporary upgrade is not allowed.
StorageType	String	No	LocalSSD	Instance storage type. Fixed value LocalSSD (local SSD disk). tip One of this parameter and NodeInfo is required, and both can be modified simultaneously. When ModifyType is set to Temporary, setting this parameter is not supported.
StorageSpace	Integer	No	100	Instance storage space. Unit is GB, with a step size of 10 GB. tip Different specifications have different storage space value ranges. For detailed information on storage space value ranges, refer to Product specifications. One of this parameter and NodeInfo is required, and both can be modified simultaneously. When ModifyType is set to Temporary, setting this parameter is not supported.
SwitchType	String	No	Immediate	Execution time. The valid values are: Immediate: switch now (default) MaintainTime: switch during the maintenance window. SpecifiedTime: switch during the specified time period. tip You can call the DescribeDBInstanceDetail API to query the instance's maintenance window. When the value is SpecifiedTime, you must set the start and end time of the time period in the SpecifiedSwitchStartTime and SpecifiedSwitchEndTime parameters.
SpecifiedSwitchStartTime	String	No	2024-12-25T14:00:00Z	The start time for execution within a specific time period. Format is yyyy-MM-ddTHH:mm:ssZ.
SpecifiedSwitchEndTime	String	No	2024-12-25T15:59:00Z	The end time for execution within the specific time period. The time format is yyyy-MM-ddTHH:mm:ssZ. tip When SwitchType is set to SpecifiedTime, this parameter is required. The minimum time period is one hour and fifty-nine minutes.
EstimateOnly	Boolean	No	true	Specifies whether to initiate a specification change assessment. Values: true: yes. false: no. Default value. tip If this parameter is specified, the system evaluates the specification change based on the parameters set for other fields without performing the actual change. After you initiate the evaluation, the system returns the EstimationResult parameter, which describes the impact of the specification change.

NodeInfoObject

Parameter	Type	Required?	Example	Description
NodeId	String	No	postgres-ca7b7019****	Node ID. You can call the DescribeDBInstanceDetail API to query. tip Required when modifying node specification and deleting nodes (ModifyDBInstancesSpec).
ZoneId	String	Yes	cn-beijing-a	The availability zone where the node is located. You can call the DescribeAvailabilityZones API to query it. tip Required when creating an instance (CreateDBInstance), restoring to a new instance (RestoreToNewInstance), and adding or modifying nodes (ModifyDBInstancesSpec). Primary, secondary, and read-only nodes can be deployed in different availability zones within the same region.
NodeType	String	Yes	Primary	Node type, with values: Primary: Primary node. Secondary: indicates the secondary node. ReadOnly: Read-only node.
NodeSpec	String	Yes	rds.postgres.1c2g	Node specification. Query specifications available for sale via DescribeDBInstanceSpecs API.
NodeOperateType	String	No	Create	Operation type. Range: Create: add. Delete: delete. Modify: modify. tip In the CreateDBInstance and RestoreToNewInstance APIs, this field can only be set to Create. When modifying instance configuration, the specified NodeOperateType must be passed in for the involved nodes.

Response parameters

Parameter	Type	Example	Description
InstanceId	String	postgres-21a3333b****	Instance ID.
OrderId	String	Order725743560891294****	Order ID. tip When EstimateOnly is true, this field returns empty.
EstimationResult	Object of ModifyDBInstanceSpecEstimationResult	Refer to the sample response.	Estimated impact on the instance after changing the current configuration. tip This field is not returned if the EstimateOnly parameter is set to false or is not specified.

ModifyDBInstanceSpecEstimationResult

Parameter	Type	Example	Description
Plans	Array of String	["AddNode", "RebuildPrimary"]	The estimated impact on the read/write connection of the instance after the configuration change. Values: AddNode: there are nodes to be added. DeleteNode: there are nodes to be deleted. RebuildPrimary: the primary database may be migrated. RebuildReadOnly: the read-only node may be migrated. RebuildSecondary: the secondary database may be migrated.
Effects	Array of String	["ReadWriteConnectionTransientError", "ReadOnlyConnectionTransientError" ]	The estimated impact on the read/write connection of the instance after the configuration change. Values: ReadOnlyConnectionTransientError: read-only connection transient disconnection. ReadWriteConnectionTransientError: read-write connection transient disconnection.

Example

Request example 1 Regular modification of specification

Sample response 1

Request example 2 Temporary upgrade example (upgrade primary and secondary node specification)

Sample response 2

Request example 3 Modification impact estimation

Sample response 3

RDS for PostgreSQL