CloudFormationで新旧LaunchConfigurationをrolling updateで切り替える ref: http://qiita.com/ryo0301/items/7b9ab1d74c230806f492

file0.txt

{
  "Resources": {
    "Group": {
      "Type": "AWS::AutoScaling::AutoScalingGroup",
      "UpdatePolicy": {
        "AutoScalingRollingUpdate": {
          "MaxBatchSize": "2",
          "MinInstancesInService": "5",
          "PauseTime": "PT10M",
          "WaitOnResourceSignals": "true"
        },
        "AutoScalingScheduledAction" : {
          "IgnoreUnmodifiedGroupSizeProperties" : "true"
        }
      },
      "Properties": {
        :
      }
    }
  }
}