**Example 1: To start an instance refresh using command line parameters** The following ``start-instance-refresh`` example starts an instance refresh using command line arguments. The optional ``preferences`` parameter specifies an ``InstanceWarmup`` of ``60`` seconds and a ``MinHealthyPercentage`` of ``50`` percent. :: aws autoscaling start-instance-refresh \ --auto-scaling-group-name my-asg \ --preferences '{"InstanceWarmup": 60, "MinHealthyPercentage": 50}' Output:: { "InstanceRefreshId": "08b91cf7-8fa6-48af-b6a6-d227f40f1b9b" } For more information, see `Start an instance refresh <https://docs.aws.amazon.com/en_us/autoscaling/ec2/userguide/start-instance-refresh.html>`__ in the *Amazon EC2 Auto Scaling User Guide*. **Example 2: To start an instance refresh using a JSON file** The following ``start-instance-refresh`` example starts an instance refresh using a JSON file. You can specify the Auto Scaling group and define your desired configuration and preferences in a JSON file, as shown in the following example. :: aws autoscaling start-instance-refresh \ --cli-input-json file://config.json Contents of ``config.json``:: { "AutoScalingGroupName": "my-asg", "DesiredConfiguration": { "LaunchTemplate": { "LaunchTemplateId": "lt-068f72b729example", "Version": "$Default" } }, "Preferences": { "InstanceWarmup": 60, "MinHealthyPercentage": 50, "AutoRollback": true, "ScaleInProtectedInstances": Ignore, "StandbyInstances": Terminate } } Output:: { "InstanceRefreshId": "08b91cf7-8fa6-48af-b6a6-d227f40f1b9b" } For more information, see `Start an instance refresh <https://docs.aws.amazon.com/en_us/autoscaling/ec2/userguide/start-instance-refresh.html>`__ in the *Amazon EC2 Auto Scaling User Guide*.