Modify the instance specification of a Classic Load Balancer - Server Load Balancer

Operation description

Pay-by-specification CLB instances have been discontinued since 00:00:00 on June 1, 2025 (UTC+8). For more information, see .

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

slb:ModifyLoadBalancerInstanceSpec

update

*loadbalancer

acs:slb:{#regionId}:{#accountId}:loadbalancer/{#loadbalancerId}

slb:tag
slb:tag

None

Request parameters

Parameter	Type	Required	Description	Example
RegionId	string	No	The region ID of the CLB instance. You can query the region ID from the list or by calling the operation.	cn-hangzhou
LoadBalancerId	string	Yes	The ID of the CLB instance.	lb-bp1b6c719df*********
LoadBalancerSpec	string	Yes	The specification of the CLB instance. Valid values: slb.s1.small slb.s2.small slb.s2.medium slb.s3.small slb.s3.medium slb.s3.large The specifications available vary by region. For more information about the specifications, see . Note When you switch a shared-resource CLB instance to a high-performance CLB instance, your service may be interrupted for 10 to 30 seconds. We recommend that you modify the specification during off-peak hours or use Alibaba Cloud DNS to schedule your workloads to another CLB instance before you modify the specification.	slb.s2.small
AutoPay	boolean	No	Specifies whether to enable automatic payment. Valid values: true: automatically completes the payment. false (default): If you select this option, you must complete the payment in the Order Center. Note This parameter takes effect only for subscription instances.	false

Response elements

Element	Type	Description	Example
	object
OrderId	integer	The order ID of the subscription CLB instance.	201429619788910
RequestId	string	The request ID.	365F4154-92F6-4AE4-92F8-7FF34B540710

Examples

Success response

JSON format

{
  "OrderId": 201429619788910,
  "RequestId": "365F4154-92F6-4AE4-92F8-7FF34B540710"
}

Error codes

HTTP status code	Error code	Error message
400	ModifySpecNotAllowed	LoadBalancerSpec not allowed for this instance
400	Operation.NotAllowed	Operation Denied, Your account does not have enough balance.
400	InvalidParameter.Bandwidth	The param Bandwidth is invalid.
400	ChangeLbSpecNotAllowed	You cannot change the specification for the specified load balancer.
400	OperationDenied.PayByCLCU	The operation is not allowed because the instanceChargeType of loadbalancer is PayByCLCU.

See Error Codes for a complete list.

Release notes

See Release Notes for a complete list.