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Server Load Balancer:ModifyLoadBalancerInstanceSpec

Last Updated:Mar 14, 2024

Modifies the specification of a Server Load Balancer (SLB) instance.


OpenAPI Explorer automatically calculates the signature value. For your convenience, we recommend that you call this operation in OpenAPI Explorer.

Authorization information

The following table shows the authorization information corresponding to the API. The authorization information can be used in the Action policy element to grant a RAM user or RAM role the permissions to call this API operation. Description:

  • Operation: the value that you can use in the Action element to specify the operation on a resource.
  • Access level: the access level of each operation. The levels are read, write, and list.
  • Resource type: the type of the resource on which you can authorize the RAM user or the RAM role to perform the operation. Take note of the following items:
    • The required resource types are displayed in bold characters.
    • If the permissions cannot be granted at the resource level, All Resources is used in the Resource type column of the operation.
  • Condition Key: the condition key that is defined by the cloud service.
  • Associated operation: other operations that the RAM user or the RAM role must have permissions to perform to complete the operation. To complete the operation, the RAM user or the RAM role must have the permissions to perform the associated operations.
OperationAccess levelResource typeCondition keyAssociated operation
  • loadbalancer
  • slb:tag

Request parameters


The region ID of the CLB instance.

You can query the region ID from the Regions and zones list or by calling the DescribeRegions operation.


The ID of the CLB instance.


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 High-performance CLB instance.

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.

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.

Response parameters


The order ID of the subscription CLB instance.


The request ID.



Sample success responses


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

Error codes

HTTP status codeError codeError messageDescription
400ModifySpecNotAllowedLoadBalancerSpec not allowed for this instance-
400Operation.NotAllowedOperation Denied, Your account does not have enough balance.-
400Operation.NotAllowedOperation Denied. Unfinished order exists.-
400Operation.NotAllowedOperation Denied. Unfinished purchase exists.The specified action is invalid. Your account contains incomplete purchase orders.
400Operation.NotAllowedOperation Denied. Prepay instance only permitted to increase loadBalancerSpec.-
400Operation.NotAllowedOperation Denied. The Purchase status of the instance is not valid.-
400InvalidParameter.BandwidthThe param Bandwidth is invalid.-
400ChangeLbSpecNotAllowedYou cannot change the specification for the specified load balancer.-
400OperationDenied.PayByCLCUThe operation is not allowed because the instanceChargeType of loadbalancer is PayByCLCU.-

For a list of error codes, visit the Service error codes.