Help Center/ Document Database Service/ API Reference/ APIs V3.0 (Recommended)/ DB Instance Management/ Adding Nodes for a Cluster Instance
Updated on 2025-10-24 GMT+08:00
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Adding Nodes for a Cluster Instance

API Description

This API is used to add nodes for a specified cluster instance.

Constraints

  • This API supports both yearly/monthly and pay-per-use DB instances.
  • Only the mongos and shard nodes can be added.

URI

  • URI format

    POST /v3/{project_id}/instances/{instance_id}/enlarge

  • URI example

    https://dds.ap-southeast-1.myhuaweicloud.com/v3/0549b4a43100d4f32f51c01c2fe4acdb/instances/9136fd2a9fcd405ea4674276ce36dae8in02/enlarge

Table 1 Path parameters

Name

Mandatory

Type

IN

Description

project_id

Yes

string

path

Explanation:

Project ID of a tenant in a region. To obtain the project ID, see Obtaining a Project ID.

Constraints:

N/A

Value range:

N/A

Default value:

N/A

instance_id

Yes

string

path

Explanation:

Instance ID, which can be obtained by calling the API described in Querying Instances and Details. If you do not have an instance, call the API described in Creating a DB Instance to create one.

Constraints:

N/A

Value range:

N/A

Default value:

N/A

Request Parameters

Table 2 Request header parameters

Name

Mandatory

Type

IN

Description

X-Auth-Token

Yes

string

header

Definition

User token obtained from IAM. For details, see Authentication.

Constraints

N/A

Value range:

N/A

Default value:

N/A
Table 3 Parameter description

Name

Type

Mandatory

Description

type

String

Yes

Explanation:

Type of the object to be scaled.

Constraints:

N/A

Value range:

  • Set the value to mongos if mongos nodes are to be added.
  • Set the value to shard if shard nodes are to be added.

Default value:

N/A

spec_code

String

Yes

Explanation:

The resource specification code. For details about how to obtain the resource specification code, see the flavors.spec_code parameter in Querying Database Specifications.

Constraints:

N/A

Value range:

N/A

Default value:

N/A

num

String

Yes

Explanation:

The number of mongos or shard nodes to be added.

Constraints:

A cluster instance supports up to 32 mongos nodes and 32 shard nodes.

Value range:

N/A

Default value:

N/A

volume

Object

No

Explanation:

The volume information. For more information, see Table 4.

Constraints:

  • This parameter is not transferred when the mongos nodes are to be added.
  • This parameter is mandatory when the shard nodes are to be added.
    NOTE:

    If multiple shards are added at a time, the shards must have the same specifications and disk capacity.

Value range:

N/A

Default value:

N/A

is_auto_pay

Boolean

No

Explanation:

Whether the order is automatically paid from your account when you add nodes to a yearly/monthly DB instance. This parameter does not affect the payment mode of automatic renewal.

Constraints:

N/A

Value range:

  • true: indicates that the order is automatically paid from the account.
  • false: indicates that the order is manually paid from the account. The default value is false.

Default value:

false
Table 4 volume field data structure description

Name

Type

Mandatory

Description

size

String

Yes

Explanation:

The disk capacity of all new shards.

Constraints:

N/A

Value range:

  • 10 GB to 5,000 GB when the shard node has fewer than 8 vCPUs.
  • 10 GB to 10,000 GB when the shard node has 8 or more vCPUs.

Default value:

N/A

Example Requests

  • Adding one mongos node whose spec_code is set to dds.mongodb.c6.medium.4.mongos 
    { 
	"type": "mongos",
	"spec_code":"dds.mongodb.c6.medium.4.mongos",
	"num": 1
}
  • Adding one shard group whose spec_code is set to dds.mongodb.c6.medium.4.mongos and storage space is 330 GB. 
    {
	"type": "shard",
	"spec_code":"dds.mongodb.c6.medium.4.shard",
	"num": 1,
        "volume": { 
             "size": 330 
    }
}

Response Parameters

  • Parameter description
    Table 5 Parameter description

    Name

    Type

    Mandatory

    Description

    job_id

    String

    Yes

    Explanation:

    Indicates the task ID.

    Value range:

    N/A

    order_id

    String

    No

    Explanation:

    The order ID. This parameter is returned only when the nodes of a yearly/monthly DB instance are added.

    Value range:

    N/A
  • Example Responses 
    { 
    "job_id": "4008c8914b624785a02ab7966d4d" 
}

Status Code

For more information, see Status Code.

Error Code

For more information, see Error Code.

Parent topic: DB Instance Management