public void setLookBackPeriod(String lookBackPeriod) {
        this.lookBackPeriod = lookBackPeriod;
    }
<p>
The preference to control the number of days the utilization metrics of the Amazon Web Services resource are
analyzed. When this preference isn't specified, we use the default value <code>DAYS_14</code>.
</p>
<note>
<p>
You can only set this preference for the Amazon EC2 instance and Auto Scaling group resource types.
</p>
</note>

@param lookBackPeriod
       The preference to control the number of days the utilization metrics of the Amazon Web Services resource
       are analyzed. When this preference isn't specified, we use the default value <code>DAYS_14</code>. </p>
       <note>
       <p>
       You can only set this preference for the Amazon EC2 instance and Auto Scaling group resource types.
       </p>
@see LookBackPeriodPreference
aws-java-sdk-computeoptimizer/src/main/java/com/amazonaws/services/computeoptimizer/model/PutRecommendationPreferencesRequest.java