Configure instance retention - Amazon EC2 Auto Scaling

Configure instance retention

Set up your Amazon EC2 Auto Scaling group to retain instances when termination lifecycle actions fail.

To use instance lifecycle policies in your Auto Scaling group, you must also configure a termination lifecycle hook. If you configure an instance lifecycle policy but don't have any termination lifecycle hooks, the policy has no effect. Instance lifecycle policies will only apply when termination lifecycle actions are abandoned, not when they complete successfully with the CONTINUE result.

Instance lifecycle policies use retention triggers to determine when to retain an instance. The TerminateHookAbandon trigger causes retention in several scenarios:

  • When you explicitly call the CompleteLifecycleAction API with the ABANDON result.

  • When a termination lifecycle action with default result ABANDON times out because the heartbeat timeout is reached without receiving a heartbeat.

  • When the global timeout is reached on a termination lifecycle action with default result ABANDON, which is 48 hours or 100 times the heartbeat timeout, whichever is smaller

Console
To configure instance retention

  1. Open the Amazon EC2 Auto Scaling console

  2. Create your Auto Scaling group (instance lifecycle policy defaults to Terminate)

  3. Go to your Auto Scaling group details page and choose the Instance Management tab

  4. In Instance lifecycle policy for lifecycle hooks, choose Retain

  5. Create your termination lifecycle hooks with:

    • Lifecycle transition set to Instance terminate

    • Default result set to Abandon

AWS CLI
To configure instance retention

Use the create-auto-scaling-group command with an instance lifecycle policy: 

aws autoscaling create-auto-scaling-group \
--auto-scaling-group-name my-asg \
--launch-template LaunchTemplateName=my-template,Version='$Latest' \
--min-size 1 \
--max-size 3 \
--desired-capacity 2 \
--vpc-zone-identifier subnet-12345678 \
--instance-lifecycle-policy file://lifecycle-policy.json

Contents of lifecycle-policy.json:

{
    "RetentionTriggers": {
        "TerminateHookAbandon": "retain"
    }
}
To add a termination lifecycle hook

Use the put-lifecycle-hook command:

aws autoscaling put-lifecycle-hook \
--lifecycle-hook-name my-termination-hook \
--auto-scaling-group-name my-asg \
--lifecycle-transition autoscaling:EC2_INSTANCE_TERMINATING \
--default-result ABANDON \
--heartbeat-timeout 300