Howtoforge published a tutorial about setting up EC2 Auto Scaling Group (ASG) on AWS.

How to setup EC2 Auto Scaling Group (ASG) on AWS

ASG(Auto Scaling Group) feature comes along with EC2 (Elastic Compute Cloud) service of AWS(Amazon Web Services) Cloud. An ASG contains a collection of EC2 instances that are treated as a logical grouping for the purpose of automatic scaling. An ASG enables to use EC2 Auto Scaling features such as health check replacements and scaling policies. It helps to maintain the number of instances in an ASG and automatic scaling of the EC2 Auto Scaling service. To create and ASG, we first need to create a Launch Configuration.

How to setup EC2 Auto Scaling Group (ASG) on AWS