Help Center/ Distributed Database Middleware/ API Reference/ APIs (Recommended)/ DDM Instances/ Scaling In a DDM Instance
Updated on 2026-06-02 GMT+08:00
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Scaling In a DDM Instance

Function

This API is used to remove nodes from a specified DDM instance.

Constraints

Make sure that the associated RDS instances are available and not undergoing other operations.

URI

POST /v2/{project_id}/instances/{instance_id}/action/reduce

Table 1 URI parameters

Parameter

Mandatory

Type

Description

project_id

Yes

String

Project ID of a tenant in a region

To obtain this value, see Obtaining a Project ID.

instance_id

Yes

String

DDM instance ID

Request Parameters

Table 2 Request header parameters

Parameter

Mandatory

Type

Description

X-Auth-Token

Yes

String

User token.

You can obtain the token by calling the IAM API used to obtain a user token.
Table 3 Request body parameters

Parameter

Mandatory

Type

Description

node_number

Yes

Integer

Number of the nodes to be removed. The maximum value is the instance nodes minus 1.

group_id

No

String

Group ID, which specifies the group that is scaled out. This parameter must be specified if there are more than one node group.

Response Parameters

Status code: 200

Table 4 Response body parameters

Parameter

Type

Description

instanceId

String

DDM instance ID

instanceName

String

DDM instance name

jobId

String

Task ID.

orderId

String

Order ID.

Status code: 400

Table 5 Response body parameters

Parameter

Type

Description

errCode

String

Service error code

externalMessage

String

Error message

Status code: 500

Table 6 Response body parameters

Parameter

Type

Description

errCode

String

Service error code

externalMessage

String

Error message

Example Request

  • Scaling in a DDM instance. The number of nodes to be removed is 2. 
    POST https://{endpoint}/v2/{project_id}/instances/{instance_id}/action/reduce

{
  "node_number" : 2
}
  • Scaling in a DDM instance that has more than one group. The number of nodes to be removed is 1. 
    POST https://{endpoint}/v2/{project_id}/instances/{instance_id}/action/reduce

{
  "group_id" : "f080abf2010d45118068c28c8958f5fcgr09",
  "node_number" : 1
}

Example Response

Status code: 200

OK

{
  "instanceId" : "28e8841d0b9c4f6a9a30742ee60e1068in09",
  "instanceName" : "BUG-ddm-fb88-test",
  "jobId" : "1eb697c0-1842-43a3-8671-f562d0385cb9"
}

Status code: 400

Bad request

{
  "externalMessage" : "Parameter error.",
  "errCode" : "DBS.280001"
}

Status code: 500

Server error

{
  "externalMessage" : "Server failure.",
  "errCode" : "DBS.200412"
}

Status Codes

Status Code

Description

200

OK

400

Bad request

500

Server error

Error Codes

For details, see Error Codes.

Parent topic: DDM Instances