GET

/#Action=PutWarmPool

http://autoscaling.{region}.amazonaws.com/#Action=PutWarmPool

Creates or updates a warm pool for the specified Auto Scaling group. A warm pool is a pool of pre-initialized EC2 instances that sits alongside the Auto Scaling group. Whenever your application needs to scale out, the Auto Scaling group can draw on the warm pool to meet its new desired capacity. For more information and example configurations, see <a href="https://docs.aws.amazon.com/autoscaling/ec2/userguide/ec2-auto-scaling-warm-pools.html">Warm pools for Amazon EC2 Auto Scaling</a> in the Amazon EC2 Auto Scaling User Guide. This operation must be called from the Region in which the Auto Scaling group was created. This operation cannot be called on an Auto Scaling group that has a mixed instances policy or a launch template or launch configuration that requests Spot Instances. You can view the instances in the warm pool using the <a>DescribeWarmPool</a> API call. If you are no longer using a warm pool, you can delete it by calling the <a>DeleteWarmPool</a> API.

Access Token Required: API Key

Query Params

AutoScalingGroupNamestringrequired

The name of the Auto Scaling group.

MaxGroupPreparedCapacityinteger

Specifies the maximum number of instances that are allowed to be in the warm pool or in any state except <code>Terminated</code> for the Auto Scaling group. This is an optional property. Specify it only if you do not want the warm pool size to be determined by the difference between the group's maximum capacity and its desired capacity. <important> If a value for <code>MaxGroupPreparedCapacity</code> is not specified, Amazon EC2 Auto Scaling launches and maintains the difference between the group's maximum capacity and its desired capacity. If you specify a value for <code>MaxGroupPreparedCapacity</code>, Amazon EC2 Auto Scaling uses the difference between the <code>MaxGroupPreparedCapacity</code> and the desired capacity instead. The size of the warm pool is dynamic. Only when <code>MaxGroupPreparedCapacity</code> and <code>MinSize</code> are set to the same value does the warm pool have an absolute size. </important> If the desired capacity of the Auto Scaling group is higher than the <code>MaxGroupPreparedCapacity</code>, the capacity of the warm pool is 0, unless you specify a value for <code>MinSize</code>. To remove a value that you previously set, include the property but specify -1 for the value.

MinSizeinteger

Specifies the minimum number of instances to maintain in the warm pool. This helps you to ensure that there is always a certain number of warmed instances available to handle traffic spikes. Defaults to 0 if not specified.

PoolStatestring

Sets the instance state to transition to after the lifecycle actions are complete. Default is <code>Stopped</code>.

Allowed:

InstanceReusePolicyobject

Indicates whether instances in the Auto Scaling group can be returned to the warm pool on scale in. The default is to terminate instances in the Auto Scaling group when the group scales in.

Actionstringrequired

Allowed:

Versionstringrequired

Allowed:

Responses

{
  "success": true,
  "data": {
    "id": "abc123",
    "created_at": "2025-01-01T00:00:00Z"
  }
}

{
  "success": false,
  "error": {
    "code": "VALIDATION_ERROR",
    "message": "Invalid request parameters"
  }
}

Language

CredentialsAPI KEY

API Key

Enter token below to save for later

cURL Request

1curl --request GET \
2     --url 'http://autoscaling.{region}.amazonaws.com/#Action=PutWarmPool' \
3     --header 'accept: application/json' \
4     --header 'content-type: application/json'

Response

1{
2  "success": true,
3  "data": {
4    "id": "abc123",
5    "created_at": "2025-01-01T00:00:00Z"
6  }
7}