AttachDBInstances - Auto Scaling - Alibaba Cloud Documentation Center

Attaches ApsaraDB RDS instances to a scaling group. You can adjust the number of ApsaraDB RDS instances attached to your scaling group based on your business requirements to increase usage flexibility.

Usage notes

Before you attach an ApsaraDB RDS instance to a scaling group, make sure that the following requirements are met:

The ApsaraDB RDS instance and the scaling group belong to the same Alibaba Cloud account.
The ApsaraDB RDS instance is unlocked. For more information about the lock policy, see ApsaraDB RDS usage notes.
The ApsaraDB RDS instance is in the Running state.
If your scaling group has an attached ApsaraDB RDS instance and you want to attach the same instance to your scaling group again, the number of the ApsaraDB RDS instances attached to your scaling group remains unchanged after the attachment. Instead, Auto Scaling automatically adds the private IP addresses of all Elastic Compute Service (ECS) instances in the scaling group to the IP address whitelist of the ApsaraDB RDS instance.

Note

After an ApsaraDB RDS instance is attached to the scaling group, the default IP address whitelist of the ApsaraDB RDS instance can contain no more than 1,000 IP addresses. For more information, see Configure IP address whitelists for the RDS instance.

Debugging

OpenAPI Explorer automatically calculates the signature value. For your convenience, we recommend that you call this operation in OpenAPI Explorer. OpenAPI Explorer dynamically generates the sample code of the operation for different SDKs.

Request parameters

Parameter	Type	Required	Example	Description
Action	String	Yes	AttachDBInstances	The operation that you want to perform. Set the value to AttachDBInstances.
ScalingGroupId	String	Yes	asg-bp1avr6ensitts3w****	The ID of the scaling group.
ForceAttach	Boolean	No	false	Specifies whether to add the private IP addresses of instances in the scaling group to the IP address whitelist of the ApsaraDB RDS instance during the attachment. Valid values: true false Default value: false.
ClientToken	String	No	123e4567-e89b-12d3-a456-42665544****	The client token that is used to ensure the idempotence of the request. You can use the client to generate the token, but you must make sure that the token is unique among different requests. The token can contain only ASCII characters and cannot exceed 64 characters in length. For more information, see Ensure idempotence.
DBInstance.N	String	No	rm-bp12cy3****	The ID of the ApsaraDB RDS instance N that you want to attach to the scaling group. Valid values of N: 1 to 5.
RegionId	String	No	cn-qingdao	The region ID of the scaling group.
AttachMode	String	No	SecurityIp	The method that you want to use to associate the database with the scaling group. Valid values: SecurityIp: Auto Scaling adds the private IP addresses of the scaled out instances to the IP address whitelist of the database. You can set the value to SecurityIp only if the database that you want to attach is an ApsaraDB RDS instance. SecurityGroup: Auto Scaling adds the security group of the effective scaling configuration to the security group whitelist of the database to enable secure access from instances in the scaling group to the database. Default value: SecurityIp.
Type	String	No	RDS	The type of the database. Valid values: RDS: an ApsaraDB RDS instance. Redis: an ApsaraDB for Redis instance. MongoDB: an ApsaraDB for MongoDB instance. Default value: RDS.

Response parameters

Parameter	Type	Example	Description
RequestId	String	473469C7-AA6F-4DC5-B3DB-A3DC0DE3****	The request ID.

Examples

Sample requests

http(s)://ess.aliyuncs.com/?Action=AttachDBInstances
&ScalingGroupId=asg-bp1avr6ensitts3w****
&ForceAttach=false
&ClientToken=123e4567-e89b-12d3-a456-42665544****
&DBInstance=["rm-bp12cy3****"]
&RegionId=cn-qingdao
&AttachMode=SecurityIp
&Type=RDS
&<Common request parameters>

Sample success responses

XML format

HTTP/1.1 200 OK
Content-Type:application/xml

<AttachDBInstancesResponse>
    <RequestId>473469C7-AA6F-4DC5-B3DB-A3DC0DE3****</RequestId>
</AttachDBInstancesResponse>

JSON format

HTTP/1.1 200 OK
Content-Type:application/json

{
  "RequestId" : "473469C7-AA6F-4DC5-B3DB-A3DC0DE3****"
}

Error codes

For a list of error codes, see Service error codes.

HTTP status code	Error code	Description	Description
404	InvalidScalingGroupId.NotFound	The specified scaling group does not exist.	The specified scaling group does not exist within your Alibaba Cloud account.
400	QuotaExceeded.RDS	"RDS" quota exceeded.	The maximum number of ApsaraDB RDS instances that can be attached to the scaling group has been reached.
400	InvalidDBInstanceId.NotFound	The specified value of parameter "%s" is not valid.	The specified ApsaraDB RDS instance does not exist.
400	IncorrectDBInstanceStatus	The current status of DB instance "%s" does not support this action.	The operation is not supported when the ApsaraDB RDS instance is in the current state.
400	QuotaExceeded.DBInstanceSecurityIP	Security IP quota exceeded in DB instance "%s".	The maximum number of IP addresses in the IP address whitelist of the ApsaraDB RDS instance has been reached.
400	InvalidInstanceIds.PrivateIpNotFound	Can not find all private ips of instances in specific scaling group.	The private IP address of an instance in the scaling group cannot be obtained.