Help Center/ GaussDB/ API Reference/ APIs (Recommended)/ Instance Management/ Adding CNs and DN Shards and Scaling Up Storage
Updated on 2025-08-18 GMT+08:00
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Adding CNs and DN Shards and Scaling Up Storage

Function

This API is used to add CNs, add DN shards, and scale up storage. Before calling this API:

Constraints

  • Scaling up storage
    • The storage space must be a multiple of (Number of shards x 4 GB).
    • All nodes must be available.

URI

POST https://{Endpoint}/v3/{project_id}/instances/{instance_id}/action

Table 1 Parameter description

Name

Mandatory

Description

project_id

Yes

Explanation:

Project ID of a tenant in a region.

For details about how to obtain the project ID, see Obtaining a Project ID.

Restrictions:

None

Value range:

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

Default value:

None

instance_id

Yes

Instance ID.

Request

Table 2 Parameter description

Name

Mandatory

Type

Description

expand_cluster

No

Object

This parameter is mandatory when you add CNs or shards.

For details, see Table 3.

enlarge_volume

No

Object

New storage space after scaling up. This parameter is mandatory for scaling up storage.

For details, see Table 6.
Table 3 expand_cluster field data structure description

Name

Mandatory

Type

Description

coordinators

No

Array of Coordinators objects

This parameter is mandatory for adding CNs. For details, see Table 4.

shard

No

Shard object

This parameter is mandatory for adding shards. For details, see Table 5.
Table 4 coordinators parameter description

Name

Mandatory

Type

Description

az_code

Yes

String

AZs to which CNs are to be added. If multiple CNs need to be added, enter the AZ where each CN is located.
Table 5 shard parameter description

Name

Mandatory

Type

Description

count

Yes

Integer

Number of shards to be added.
Table 6 enlarge_volume field data structure description

Name

Mandatory

Type

Description

size

Yes

Integer

Storage space, which must always be a multiple of (Number of shards x 4 GB). Value range: (Number of shards x 40 GB) to (Number of shards x 24 TB).

Response Parameters

Table 7 Response parameters

Name

Type

Description

job_id

String

Task ID. This parameter is returned when your instance is billed at a pay-per-use basis.

Example Request

  • Adding a CN 
    POST https://gaussdb-opengauss.eu-west-101.myhuaweicloud.eu/v3/0483b6b16e954cb88930a360d2c4e663/instances/dsfae23fsfdsae3435in14/action
{
    "expand_cluster": {
        "coordinators": [
            {
            }
        ]
    }
}
  • Adding multiple CNs 
    POST https://gaussdb-opengauss.eu-west-101.myhuaweicloud.eu/v3/0483b6b16e954cb88930a360d2c4e663/instances/dsfae23fsfdsae3435in14/action
{
    "expand_cluster": {
        "coordinators": [
            {
            },
            {
            },
            {
            }
        ]
    }
}
  • Adding a DN shard 
    POST https://gaussdb-opengauss.eu-west-101.myhuaweicloud.eu/v3/0483b6b16e954cb88930a360d2c4e663/instances/dsfae23fsfdsae3435in14/action
{
    "expand_cluster": {
        "shard": {
            "count": 1
        }
    }
}
  • Scaling up storage to 400 GB 
    POST https://gaussdb-opengauss.eu-west-101.myhuaweicloud.eu/v3/0483b6b16e954cb88930a360d2c4e663/instances/dsfae23fsfdsae3435in14/action
{
    "enlarge_volume": {
        "size": 400
    }
}

Example Response

{
	"job_id": "2b414788a6004883a02390e2eb0ea227"
}

Status Code

Error Code

For details, see Error Codes.

Parent topic: Instance Management