Help Center/ GaussDB/ API Reference/ APIs (Recommended)/ Instance Management/ Changing the CPU and Memory Specifications of an Instance
Updated on 2025-12-26 GMT+08:00
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Changing the CPU and Memory Specifications of an Instance

Function

This API is used to change the CPU and memory specifications of a DB instance. Before calling this API:

Constraints

  • The OS architecture of the new specifications must be the same as that of the old specifications.

Debugging

You can debug this API in API Explorer.

URI

PUT /v3/{project_id}/instances/{instance_id}/flavor

Table 1 Parameter description

Parameter

Mandatory

Description

project_id

Yes

Definition

Project ID of a tenant in a region.

To obtain the value, see Obtaining a Project ID.

Constraints

N/A

Range

The value can contain 32 characters. Only letters and digits are allowed.

Default Value

N/A

instance_id

Yes

Definition

Instance ID, which uniquely identifies an instance.

Constraints

N/A

Range

The value can contain 36 characters. Only letters and digits are allowed.

Default Value

N/A

Request Parameters

Table 2 Parameter description

Name

Mandatory

Type

Description

flavor_ref

Yes

String

Definition

New specification code. To obtain its value, see the Specification Code column in Table 1.

To obtain its value, see the spec_code field in Querying Instance Specifications.

Constraints

N/A

Range

N/A

Default Value

N/A

is_auto_pay

No

Boolean

Definition

Whether the order will be automatically paid after yearly/monthly instances are created. This parameter does not affect the payment mode of automatic renewal.

Constraints

N/A

Range

  • true: The order is automatically paid from the account.
  • false: The order is manually paid from the account.

Default Value

false

cn_concurrent_resize_num

No

Integer

Definition

Number of concurrent CN specification changes.

You can increase the number of CN specification change operations that can be performed concurrently to speed up the specification change. The default value is recommended. If you need to adjust the number, evaluate the workload changes of remaining CNs based on the current system load to ensure that the service stability and interruption duration are within acceptable ranges.

Constraints

This parameter takes effect only for instances in the independent deployment model.

Range

[1,floor(Total number of CNs/2)]. Specifications of up to 20 CNs can be changed in a single batch.

Default Value

1

dn_concurrent_resize_num

No

Integer

Definition

Number of concurrent DN specification changes.

You can increase the number of DN specification change operations that can be performed concurrently to speed up the specification change. The default value is recommended. If you need to adjust the number, evaluate the number of DN switchovers in a short period based on the current system load to ensure that the service stability and interruption duration are within acceptable ranges.

Constraints

N/A

Range

  • [1,Total number of shards] when the total number of shards is less than or equal to 5.
  • [1,max(floor(Number of shards/2),5)] when the total number of shards is greater than 5. Specifications of up to 20 DN shards can be changed in a single batch.

Default Value

The default value varies depending on the total number of shards in an instance:

  • When the instance contains five or fewer shards, the specifications of all shards are changed together by default.
  • When the instance contains more than five shards, the specifications of five shards are changed at a time by default, with the final batch possibly containing fewer than five shards.

Response Parameters

Table 3 Response parameter description

Name

Type

Description

job_id

String

Definition

ID of changing instance specifications. This parameter is returned only when you change the specifications of a pay-per-use instance.

Range

N/A

order_id

String

Definition

Order ID. This parameter is returned only when you change the specifications of a yearly/monthly instance.

Range

N/A

Example Request

Changing the specifications of a pay-per-use instance to 16 vCPUs and 128 GB

PUT https://gaussdb-opengauss.ap-southeast-1.myhuaweicloud.com/opengauss/v3/0483b6b16e954cb88930a360d2c4e663/instances/dsfae23fsfdsae3435in14/flavor
{ 
        "flavor_ref":"gaussdb.opengauss.ee.dn.m6.4xlarge.8.in" 
 }
Changing the specifications of a yearly/monthly instance from 8 vCPUs and 64 GB to 16 vCPUs and 128 GB 
PUT https://gaussdb-opengauss.ap-southeast-1.myhuaweicloud.com/opengauss/v3/0483b6b16e954cb88930a360d2c4e663/instances/dsfae23fsfdsae3435in14/flavor
{ 
        "flavor_ref":"gaussdb.opengauss.ee.dn.m6.4xlarge.8.in",
        "is_auto_pay":true
 }

Example Response

Instance specifications changed.

{
	"job_id": "2b414788a6004883a02390e2eb0ea227"
}

Status Codes

Error Codes

For details, see Error Codes.

Parent topic: Instance Management