Adding a Read Replica to an Instance

API Description

This API is used to add read replicas to DDS instances.

Restrictions

• This API can only be used to add read replicas to replica set instances and cluster instances.
• A maximum of five read replicas can be added to a replica set instance.
• In a cluster instance, up to five read replicas can be added to a shard.
• In a cluster instance, read replicas can be added to only one shard at a time.
• The synchronization delay cannot be set for cluster instances. The default value is 0.
• This API supports both yearly/monthly and pay-per-use DB instances.

URI

• URI format

  POST https://{Endpoint}/v3/{project_id}/instances/{instance_id}/readonly-node

• URI example
  https://dds.cn-north-1.myhuaweicloud.com/v3/0549b4a43100d4f32f51c01c2fe4acdb/instances/9136fd2a9fcd405ea4674276ce36dae8in02/readonly-node

  Table 1 Request parameters

  Name	Mandatory	Type	Description
  project_id	Yes	String	Definition Project ID of a tenant in a region. To obtain the project ID, see Obtaining a Project ID. Constraints N/A Range N/A Default Value N/A
  instance_id	Yes	String	Definition 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 Range N/A Default Value N/A

  Table 2 Request header parameters

  Name	Mandatory	Type	Description
  X-Auth-Token	Yes	String	Definition User token obtained from IAM. For details, see Authentication. Constraints N/A Range N/A Default Value N/A

Request Parameters

• Parameter description

  Table 3 Request body parameters

  Name	Mandatory	Type	Description
  spec_code	Yes	String	Definition The resource specification code. For details about how to obtain the value, see the parameter value in Querying Database Specifications. Example: dds.mongodb.c6.large.4.rr Constraints N/A Range N/A Default Value N/A
  num	Yes	Integer	Definition Number of read replicas to be added. Constraints N/A Range 1–5 Default Value N/A
  delay	No	Integer	Definition Synchronization delay. Constraints This parameter cannot be set for cluster instances. Range 0 to 1,200 ms Default Value 0
  is_auto_pay	No	Boolean	Definition Whether the order is automatically paid from your account when you add read replicas to a yearly/monthly DB instance. 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

Example Request

Adding one read replica who spec_code is set to dds.mongodb.c6.large.4.rr, and delay is set to 0

POST https://dds.cn-north-1.myhuaweicloud.com/v3/0549b4a43100d4f32f51c01c2fe4acdb/instances/9136fd2a9fcd405ea4674276ce36dae8in02/readonly-node 
 
{  
    "spec_code": "dds.mongodb.c6.large.4.rr",
    "num" : 1,  
    "delay" : 0 
}

Response Parameters

Example Response

{ 
  "job_id" : "4008c8914b624785a02ab7966d4d" 
}

Status Code

For details, see Status Code.

Error Code

For details, see Error Code.