Information
Auto Scaling helps maintain application availability and allows you to scale your Amazon EC2 capacity up or down automatically according to conditions you define.
You can use Auto Scaling to help ensure that you are running your desired number of Amazon EC2 instances or can automatically increase the number of Amazon EC2 instances during demand spikes to maintain performance and decrease capacity during lulls to reduce costs.
These properties can be defined within the Auto-Scaling Group configuration.
Additional properties can be defined through the launch configuration such as:
* Instance Type
* Amazon Machine Image (Pre-configured Operating System Images - allows for O.S Hardening)
* IAM Role
* Security Groups
Instances within the App Tier Auto-Scaling Group, are launched using the Security Group configured in the Auto-Scaling Launch Configuration. This Security Group allows only traffic specific to the App Tier, and you must ensure that only this App Tier Security Group is configured in the Launch Configuration.
Solution
Using the Amazon unified command line interface:
* Create new launch configuration for the App tier using the App Tier Security Group :
aws autoscaling create-launch-configuration --launch-configuration-name <_new_app_tier_launch_config_> --image-id <_app_tier_ami>_ --key-name <_your_key_pair>_ --security-groups <app_tier_security_group_>_ --instance-type <_desired_instance_type>_ --iam-instance-profile <_app_tier_instance_profile>_