Customizing the MCS Autoscaler for ECS

This Tutorial will explain how Custom ECS Autoscaler work and includes a guide on how to setup a Custom ECS AutoScaler in your ECS integrated Elastigroup.

How it works

The Spotinst ECS autoscaler dynamically scales your cluster up to ensure there are always sufficient resources to run all tasks. With the “Custom” option the Spotinst ECS autoscaler analyzes your ECS cluster topology and according to your specified buffer of spare capacity, called Headroom [link to headroom concept], configures your cluster’s autoscaling for optimized performance and costs.

  1. Enable ECS AutoScaler in custom mode:

In Elastigroup’s Creation Wizard, under the Compute tab scroll down to the Integrations section and enable the ECS AutoScaler. Once the Autoscaler is enabled select Custom mode and configure the following settings:

  • Autoscaler cooldown time: Cooldown is the number of seconds between one scaling activity to the next one.
  • Evaluation periods: The number of consecutive periods that should pass before the scaling action is triggered.
Note: The default is 5 evaluation periods (1 evaluation period = 1 minute).
  • Headroom units count: Headroom is a buffer of spare capacity (in terms of both memory and CPU) that makes sure that when you want to scale more tasks, you don’t have to wait for new instances to launch while preventing instances from being over-utilized. For more on the Headroom concept see Autoscaler Headroom.