All Products
Search
Document Center

PolarDB:CreateDBNodes

Last Updated:Oct 16, 2025

Adds read-only nodes to a PolarDB cluster.

Try it now

Try this API in OpenAPI Explorer, no manual signing needed. Successful calls auto-generate SDK code matching your parameters. Download it with built-in credential security for local usage.

Test

RAM authorization

The table below describes the authorization required to call this API. You can define it in a Resource Access Management (RAM) policy. The table's columns are detailed below:

  • Action: The actions can be used in the Action element of RAM permission policy statements to grant permissions to perform the operation.

  • API: The API that you can call to perform the action.

  • Access level: The predefined level of access granted for each API. Valid values: create, list, get, update, and delete.

  • Resource type: The type of the resource that supports authorization to perform the action. It indicates if the action supports resource-level permission. The specified resource must be compatible with the action. Otherwise, the policy will be ineffective.

    • For APIs with resource-level permissions, required resource types are marked with an asterisk (*). Specify the corresponding Alibaba Cloud Resource Name (ARN) in the Resource element of the policy.

    • For APIs without resource-level permissions, it is shown as All Resources. Use an asterisk (*) in the Resource element of the policy.

  • Condition key: The condition keys defined by the service. The key allows for granular control, applying to either actions alone or actions associated with specific resources. In addition to service-specific condition keys, Alibaba Cloud provides a set of common condition keys applicable across all RAM-supported services.

  • Dependent action: The dependent actions required to run the action. To complete the action, the RAM user or the RAM role must have the permissions to perform all dependent actions.

Action

Access level

Resource type

Condition key

Dependent action

polardb:CreateDBNodes

create

*dbcluster

acs:polardb:{#regionId}:{#accountId}:dbcluster/{#dbclusterId}

None

None

Request parameters

Parameter

Type

Required

Description

Example

ResourceGroupId

string

No

The ID of the resource group.

rg-************

DBClusterId

string

Yes

The cluster ID.

pc-*************

ClientToken

string

No

A client token to ensure the idempotence of the request. The client generates this value, which must be unique among different requests. The token is case-sensitive and can contain up to 64 ASCII characters.

6000170000591aed949d0f54a343f1a4233c1e7d1c5c******

EndpointBindList

string

No

The ID of the cluster endpoint to which the new node is added. To add the new node to multiple endpoints, separate the endpoint IDs with commas (,).

Note

  • To view the details of the cluster endpoints, including the endpoint IDs, call the DescribeDBClusterEndpoints operation.

  • You can specify the IDs of the default cluster endpoint and custom cluster endpoints.

  • If you leave this parameter empty, the new node is added to all cluster endpoints for which the Auto Add New Nodes feature is enabled. The AutoAddNewNodes parameter is set to Enable for these endpoints.

pe-****************,pe-****************

PlannedStartTime

string

No

The earliest start time to add the node. The task is executed within a specified period of time. Specify the time in the YYYY-MM-DDThh:mm:ssZ format. The time must be in UTC.

Note

  • The start time can be any point in time within the next 24 hours. For example, if the current time is 2021-01-14T09:00:00Z, you can specify a start time that is between 2021-01-14T09:00:00Z and 2021-01-15T09:00:00Z.

  • If you leave this parameter empty, the task to add the node is executed immediately.

2021-01-14T09:00:00Z

PlannedEndTime

string

No

The latest start time for the scheduled task. Specify the time in the YYYY-MM-DDThh:mm:ssZ format. The time must be in UTC.

Note

  • The latest start time must be at least 30 minutes later than the earliest start time.

  • If you specify PlannedStartTime but not this parameter, the latest start time is PlannedStartTime + 30 minutes. For example, if you set PlannedStartTime to 2021-01-14T09:00:00Z and leave this parameter empty, the task will start at the latest by 2021-01-14T09:30:00Z.

2021-01-14T09:30:00Z

DBNode

array<object>

Yes

The information about the new node.

object

No

TargetClass

string

No

The specifications of the new node. The specifications must be the same as the original node. See more below:

Note

  • You must specify at least one of DBNode.N.ZoneId and DBNode.N.TargetClass. N is an integer that starts from 1. The maximum value of N is 16 minus the number of existing nodes.

  • Currently, you can add multiple read-only nodes to a PolarDB for MySQL cluster at a time. You can add up to 15 read-only nodes.

  • Required for PolarDB for PostgreSQL (Oracle Compatible) clusters and PolarDB for PostgreSQL clusters. Optional for PolarDB for MySQL clusters.

polar.mysql.x4.medium

ZoneId

string

No

The zone ID of the new node. The zone must be the same as the original node. To query the zone ID, call the DescribeRegions operation.

Note

  • You must specify at least one of DBNode.N.ZoneId and DBNode.N.TargetClass. N is an integer that starts from 1. The maximum value of N is 16 minus the number of existing nodes.

  • Currently, you can add multiple read-only nodes to a PolarDB for MySQL cluster at a time. You can add up to 15 read-only nodes.

  • This parameter is required for PolarDB for PostgreSQL (Oracle Compatible) clusters and PolarDB for PostgreSQL clusters. This parameter is optional for PolarDB for MySQL clusters.

cn-qingdao-c

DBNodeType

string

No

The node type. Valid values:

  • RO

  • STANDBY

  • DLNode

Valid values:

  • DLNode :

    AI node

  • STANDBY :

    Standby node

  • RO :

    Read-only node

RO

ImciSwitch

string

No

Specifies whether to enable the In-Memory Column Index (IMCI) feature. Valid values:

  • ON: Enables the feature.

  • OFF: Disables the feature. This is the default value.

Note

This parameter is not supported for PolarDB for PostgreSQL (Oracle Compatible) clusters and PolarDB for PostgreSQL clusters.

ON

Response elements

Element

Type

Description

Example

object

DBNodeIds

object

DBNodeId

array

A list of created DBNodeIds.

string

A list of created DBNodeIds.

pi-***************

RequestId

string

The request ID.

E053E730-5755-4AA9-AA9D-A47867******

DBClusterId

string

The ID of the database cluster.

pc-***************

OrderId

string

The order ID.

2148126708*****

Examples

Success response

JSON format

{ "DBNodeIds": { "DBNodeId": [ "pi-***************" ] }, "RequestId": "E053E730-5755-4AA9-AA9D-A47867******", "DBClusterId": "pc-***************", "OrderId": "2148126708*****" }

Error codes

HTTP status code

Error code

Error message

Description

400

ORDER.ARREARAGE

您有欠费账单，不符合购买条件，请先结清账单后再购买

You must settle the overdue payments for your account before you can make a purchase.

400

InvalidDBNodeNum.Malformed

The number of parameter DBNode.N is not valid.

The specified number of database nodes is invalid.

400

InvalidDBNode.Malformed

The specified parameter DBNode.N is not valid.

The specified DBNode.N parameter is invalid.

400

OperationDenied.CreateDBNodesWithStrictConsistencyOn

3AZ cluster does not allow create db nodes.

Nodes cannot be added for multi-zone clusters.

400

InvalidZoneId.Malformed

The specified parameter ZoneId is not valid.

The specified ZoneId parameter is invalid.

403

OperationDenied.ClusterCategory

The operation is not permitted due to cluster category.

This series is not supported by the cluster.

403

OperationDenied.DbVersion

The operation is not permitted due to DbVersion.

This operation is not supported by the database version.

404

InvalidDBClusterId.NotFound

The DBClusterId provided does not exist in our records.

The specified DBClusterId parameter does not exist in the current record.

404

InvalidDBClusterId.Malformed

The specified parameter DBClusterId is not valid.

The specified DBClusterId parameter is invalid.

See Error Codes for a complete list.

Release notes

See Release Notes for a complete list.