AWS EC2 Server Group Launch Settings

Launch Settings

An AWS Server Group can be set up with either a launch template or a launch configuration. However, you must enable launch templates support for all of your applications if you want to use the latest AWS features. AWS strongly recommends using launch templates over launch configurations because launch configurations do NOT provide full functionality for Amazon EC2 Auto Scaling or Amazon EC2.

• (Newer) Launch template is similar to a launch configuration, in that it specifies instance configuration information. However, defining a launch template instead of a launch configuration, you can:

  • create and maintain multiple versions of a launch template.
  • access the launch-template-only AWS features like diversification of instances of a server group across instance type, purchase options (On-Demand / Spot), and allocation strategies.
    • Enable launch templates support .
    • Learn more about launch template features](/docs/setup/other_config/server-group-launch-settings/aws-ec2/launch-templates).

• (Older) Launch configuration is an instance configuration template that an AWS Auto Scaling group uses to launch EC2 instances.

Enhance your EC2 Spot experience

Amazon EC2 Spot Instances let you take advantage of unused EC2 capacity in the AWS Cloud. Spot Instances are available at up to a 90% discount compared to On-Demand prices.

Spot Instances are tightly integrated with AWS services, like Amazon EC2 Auto Scaling. Auto Scaling groups let you tweak a number of configuration parameters that decide how to launch and maintain your applications running on Spot Instances.

Here are some configuration parameters to consider:

• Use MixedInstancesPolicy features detailed here (requires Launch Template support to be enabled). For example,
  • Launch your Spot capacity from optimal instance pools using spotAllocationStrategy capacity-optimized
  • Specify a flexible set of instance types for your server group using launch template overrides.
• Enable capacityRebalance to allow EC2 Auto Scaling to monitor and automatically respond to changes that affect availability of your Spot Instances. This feature works best with the capacity-optimized spotAllocationStrategy. For more information about capacity rebalancing, see Amazon EC2 Auto Scaling Capacity Rebalancing

Learn more about AWS recommended best practices .