# CfnAutoScalingInstanceRefresh

To specify how AWS CloudFormation handles instance refresh for an Auto Scaling group, use the AutoScalingInstanceRefresh update policy.

When properties that trigger an instance refresh change
(such as LaunchTemplate or MixedInstancesPolicy), CloudFormation starts an instance refresh to
replace instances gradually.

This policy is mutually exclusive with AutoScalingRollingUpdate.

- Source: [`core/lib/cfn-resource-policy.ts`](https://github.com/aws/aws-cdk/blob/v2.275.0/packages/aws-cdk-lib/core/lib/cfn-resource-policy.ts#L314)
- Type last changed: v2.263.0 · 31 Jul 2026

## Example

```ts
// The code below shows an example of how to instantiate this type.
// The values are placeholders you should change.
import * as cdk from 'aws-cdk-lib';
const cfnAutoScalingInstanceRefresh: cdk.CfnAutoScalingInstanceRefresh = {
  strategy: 'strategy',

  // the properties below are optional
  preferences: {
    alarmSpecification: {
      alarms: ['alarms'],
    },
    bakeTime: 123,
    checkpointDelay: 123,
    checkpointPercentages: [123],
    instanceWarmup: 123,
    maxHealthyPercentage: 123,
    minHealthyPercentage: 123,
    scaleInProtectedInstances: 'scaleInProtectedInstances',
    skipMatching: false,
    standbyInstances: 'standbyInstances',
  },
};
```

## Properties

- `preferences`: [CfnAutoScalingInstanceRefreshPreferences](/cdk/api/v2/docs/aws-cdk-lib.CfnAutoScalingInstanceRefreshPreferences.html) — The preferences for the instance refresh.

- `strategy`: string (required) — The strategy to use for the instance refresh.