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# AWS::MediaTailor::PrefetchSchedule TrafficShapingRetrievalWindow
<a name="aws-properties-mediatailor-prefetchschedule-trafficshapingretrievalwindow"></a>

The configuration that tells AWS Elemental MediaTailor how many seconds to spread out requests to the ad decision server (ADS). Instead of sending ADS requests for all sessions at the same time, MediaTailor spreads the requests across the amount of time specified in the retrieval window.

## Syntax
<a name="aws-properties-mediatailor-prefetchschedule-trafficshapingretrievalwindow-syntax"></a>

To declare this entity in your Amazon CloudFormation template, use the following syntax:

### JSON
<a name="aws-properties-mediatailor-prefetchschedule-trafficshapingretrievalwindow-syntax.json"></a>

```
{
  "[RetrievalWindowDurationSeconds](#cfn-mediatailor-prefetchschedule-trafficshapingretrievalwindow-retrievalwindowdurationseconds)" : {{Integer}}
}
```

### YAML
<a name="aws-properties-mediatailor-prefetchschedule-trafficshapingretrievalwindow-syntax.yaml"></a>

```
  [RetrievalWindowDurationSeconds](#cfn-mediatailor-prefetchschedule-trafficshapingretrievalwindow-retrievalwindowdurationseconds): {{Integer}}
```

## Properties
<a name="aws-properties-mediatailor-prefetchschedule-trafficshapingretrievalwindow-properties"></a>

`RetrievalWindowDurationSeconds`  <a name="cfn-mediatailor-prefetchschedule-trafficshapingretrievalwindow-retrievalwindowdurationseconds"></a>
The amount of time, in seconds, that MediaTailor spreads prefetch requests to the ADS.   
*Required*: No  
*Type*: Integer  
*Update requires*: [Replacement](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)