You can call this operation to move the specified instances in a scaling group into the standby state.


If a Server Load Balancer (SLB) instance is specified in the scaling group, the weight of an ECS instance attached to the SLB instance is set to 0.

  • When an instance is in the standby state, you can manually remove it from the scaling group and delete it.
  • The changes in the number of instances in a scaling group and scale-in events triggered by monitoring tasks will not remove ECS instances in the standby state.
  • When an instance in the standby state is unhealthy (stopped or restarted), its health check status is not updated and it will not trigger a scale-in event to remove unhealthy instances. The health check status is updated only after the instance is moved out of the standby state by calling the ExitStandby operation.


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
InstanceId.N RepeatList Yes i-28wt4****

The IDs of the ECS instances.

ScalingGroupId String Yes AG6CQdPU8OKdwLjgZcJ****

The ID of the scaling group.

Action String Yes EnterStandby

The operation that you want to perform. Set the value to EnterStandby.

Response parameters

Parameter Type Example Description
RequestId String 473469C7-AA6F-4DC5-B3DB-A3DC0DE3C83E

The ID of the request.


Sample requests
&<Common request parameters>

Sample success responses

XML format


JSON format


Error codes

For more information about error codes, visit API Error Center.

HTTP status code

Error code

Error message




A required authorization for the specified action is not supplied.

The error message returned because the RAM user does not have permissions to call this operation. Contact the Alibaba Cloud account to grant permissions to the RAM user before trying again.



Instance "XXX" does not exist.

The error message returned because the specified ECS instance does not exist.



The specified scaling group does not exist.

The error message returned because the specified scaling group does not exist.