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Examples for creating and managing warm pools with the Amazon CLI

You can create and manage warm pools using the Amazon Web Services Management Console, Amazon Command Line Interface (Amazon CLI), or SDKs.

The following examples show you how to create and manage warm pools using the Amazon CLI.

Example 1: Keep instances in the Stopped state

The following put-warm-pool example creates a warm pool that keeps instances in a Stopped state.

aws autoscaling put-warm-pool --auto-scaling-group-name my-asg /
  --pool-state Stopped

Example 2: Keep instances in the Running state

The following put-warm-pool example creates a warm pool that keeps instances in a Running state instead of a Stopped state.

aws autoscaling put-warm-pool --auto-scaling-group-name my-asg /
  --pool-state Running

Example 3: Keep instances in the Hibernated state

The following put-warm-pool example creates a warm pool that keeps instances in a Hibernated state instead of a Stopped state. This lets you stop instances without deleting their memory contents (RAM).

aws autoscaling put-warm-pool --auto-scaling-group-name my-asg /
  --pool-state Hibernated

Example 4: Return instances to the warm pool when scaling in

The following put-warm-pool example creates a warm pool that keeps instances in a Stopped state and includes the --instance-reuse-policy option. The instance reuse policy value '{"ReuseOnScaleIn": true}' tells Amazon EC2 Auto Scaling to return instances to the warm pool when your Auto Scaling group scales in.

aws autoscaling put-warm-pool --auto-scaling-group-name my-asg /
  --pool-state Stopped --instance-reuse-policy '{"ReuseOnScaleIn": true}'

Example 5: Specify the minimum number of instances in the warm pool

The following put-warm-pool example creates a warm pool that maintains a minimum of 4 instances, so that there are at least 4 instances available to handle traffic spikes.

aws autoscaling put-warm-pool --auto-scaling-group-name my-asg /
  --pool-state Stopped --min-size 4

Example 6: Define the warm pool size using a custom specification

By default, Amazon EC2 Auto Scaling manages the size of your warm pool as the difference between the maximum and desired capacity of the Auto Scaling group. However, you can manage the size of the warm pool independently from the group's maximum capacity by using the --max-group-prepared-capacity option.

The following put-warm-pool example creates a warm pool and sets the maximum number of instances that can exist concurrently in both the warm pool and Auto Scaling group. If the group has a desired capacity of 800, the warm pool will initially have a size of 100 as it initializes after running this command.

aws autoscaling put-warm-pool --auto-scaling-group-name my-asg /
  --pool-state Stopped --max-group-prepared-capacity 900

To maintain a minimum number of instances in the warm pool, include the --min-size option with the command, as follows.

aws autoscaling put-warm-pool --auto-scaling-group-name my-asg /
  --pool-state Stopped --max-group-prepared-capacity 900 --min-size 25

Example 7: Define an absolute warm pool size

If you set the same values for the --max-group-prepared-capacity and --min-size options, the warm pool has an absolute size. The following put-warm-pool example creates a warm pool that maintains a constant warm pool size of 10 instances.

aws autoscaling put-warm-pool --auto-scaling-group-name my-asg /
  --pool-state Stopped --min-size 10 --max-group-prepared-capacity 10

Example 8: Delete a warm pool

Use the following delete-warm-pool command to delete a warm pool.

aws autoscaling delete-warm-pool --auto-scaling-group-name my-asg

If there are instances in the warm pool, or if scaling activities are in progress, use the delete-warm-pool command with the --force-delete option. This option also terminates the Amazon EC2 instances and any outstanding lifecycle actions.

aws autoscaling delete-warm-pool --auto-scaling-group-name my-asg --force-delete