EC2 Auto Scaling customers can now use Amazon CloudWatch Metric Math to customize the metrics they use with Target Tracking policy without actually having to publish and pay for customized metrics. Customers can use both arithmetic operators (such as +, -, /, and *) and mathematical functions (such as Sum and Average) to easily create custom metrics based on existing CloudWatch metrics. Target Tracking, like other EC2 Auto Scaling policies, helps customers maintain high availability while reducing costs by auto scaling their environments to meet changing demand. Specifically, Target Tracking works like a thermostat: it constantly changes the capacity of an Auto Scaling group to maintain the specified metric at a customer-defined target level. Today’s release makes it easier and cheaper to configure Target Tracking with custom metrics.