AWS Auto Scaling 

AWS Auto Scaling lets you build scaling plans that automate how groups of different resources respond to changes in demand. You can optimize availability, costs, or a balance of both. AWS Auto Scaling automatically creates all of the scaling policies and sets targets for you, based on your needs.

Auto scaling

AWS Auto Scaling monitors your applications and automatically adjusts capacity to maintain steady, predictable performance at the lowest possible cost. Using AWS Auto Scaling, you can set up application scaling for multiple resources across multiple services in minutes. 

The service provides a simple, powerful user interface that lets you build scaling plans for resources including Amazon EC2 instances and Spot Fleets, and other compute and database services that will be addressed later in the course. 

AWS Auto Scaling makes scaling simple with recommendations that let you optimize performance, costs, or balance between them.

Amazon EC2 Auto Scaling

With Amazon EC2 Auto Scaling, you can build scaling plans that automate how groups of different EC2 resources respond to changes in demand. You can optimize availability, costs, or a balance of both.

If you specify scaling policies, then Amazon EC2 Auto Scaling can launch or terminate instances as demand on your application increases or decreases. Amazon EC2 Auto Scaling integrates with ELB so you can attach one or more load balancers to an existing Amazon EC2 Auto Scaling group. After you attach the load balancer, it automatically registers the instances in the group and distributes incoming traffic across the instances.

Amazon EC2 Auto Scaling components

Launch template	Amazon EC2 Auto Scaling group	Auto scaling policy
What resources do you need?	Where and how many do you need?	When and for how long do you need them?
AMI Instance type Security groups Roles	VPC and subnets Load balancer Define: Minimum instances Maximum instances Desired capacity (optional)	Scheduled On-demand Predictive auto scaling Scale-out policy Scale-in policy

Launch template

A launch template is an instance configuration template that a group uses to launch EC2 instances. Included are the instance type, EBS volume, ID of the AMI, a key pair, security groups, and the other parameters that you use to launch EC2 instances.

Launch templates are the preferred method to configure your group in AWS because they provide:

• A consistent experience
• Simple permissions
• Governance and best practices
• Increased productivity

Optimize cost with EC2 Auto Scaling

Amazon EC2 Auto Scaling supports multiple purchasing options within the same group. You can launch and automatically scale a fleet of On-Demand Instances and Spot Instances within a single Auto Scaling group. In addition to receiving discounts for using Spot Instances, you can use Reserved Instances or a Savings Plan to receive discounted rates of the regular On-Demand Instance pricing. All of these factors combined help you to optimize your cost savings for EC2 instances, while making sure that you obtain the desired scale and performance for your application.

Using Amazon EC2 Fleet, you can define a combination of EC2 instance types to make up the desired capacity of your group. This is defined as a percentage of each type of purchasing option. Amazon EC2 Auto Scaling will maintain the desired cost optimization as your group scales in or out. Groups made up of mixed fleets still support the same lifecycle hooks, instance health checks, and scheduled scaling as a single-fleet group.

Regards

Osama