Auto Scaling
API Reference (API Version 2011-01-01)


Describes one or more scaling activities for the specified Auto Scaling group.

Request Parameters

For information about the parameters that are common to all actions, see Common Parameters.


The activity IDs of the desired scaling activities. If you omit this parameter, all activities for the past six weeks are described. If you specify an Auto Scaling group, the results are limited to that group. The list of requested activities cannot contain more than 50 items. If unknown activities are requested, they are ignored with no error.

Type: array of Strings

Pattern: [\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*

Required: No


The name of the group.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 1600.

Pattern: [\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*

Required: No


The maximum number of items to return with this call.

Type: Integer

Required: No


The token for the next set of items to return. (You received this token from a previous call.)

Type: String

Pattern: [\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*

Required: No

Response Elements

The following elements are returned by the service.


The scaling activities. Activities are sorted by start time. Activities still in progress are described first.

Type: array of Activity objects


The token to use when requesting the next set of items. If there are no additional items to return, the string is empty.

Type: String

Pattern: [\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*


For information about the errors that are common to all actions, see Common Errors.


The NextToken value is not valid.

HTTP Status Code: 400


You already have a pending update to an Auto Scaling resource (for example, a group, instance, or load balancer).

HTTP Status Code: 500


Sample Request

Sample Response

<DescribeScalingActivitiesResponse xmlns="">
        <Cause>At 2012-04-12T17:31:30Z a user request created an AutoScalingGroup changing the desired capacity from 0 to 1.  At 2012-04-12T17:32:07Z an instance was started in response to a difference between desired and actual capacity, increasing the capacity from 0 to 1.</Cause>
        <Description>Launching a new EC2 instance.  Status Reason: The image id 'ami-4edb0327' does not exist. Launching EC2 instance failed.</Description>
        <StatusMessage>The image id 'ami-4edb0327' does not exist. Launching EC2 instance failed.</StatusMessage>