Explanation
Why the waste happens and who it affects.
This leads to idle compute capacity and unnecessary EC2 charges.Instead, ECS Capacity Providers support target tracking scaling policies that can scale the ASG to zero when idle and automatically increase capacity when new tasks or services are scheduled. Failing to adopt this pattern results in persistent idle infrastructure and unnecessary costs in ECS environments that do not require always-on compute.
Billing model
The pricing dimensions that drive this cost.
- EC2 container instances in ECS are billed like regular EC2 instances - by the second, based on type and size
- ASGs that maintain a minimum capacity > 0 will keep EC2 instances running even if no ECS services or tasks are scheduled
- ECS Capacity Providers can scale ASGs dynamically using target tracking, enabling min = 0 when idle
How to detect
4 checks to find it in your estate.
- Identify ECS clusters using EC2 launch type
- Check the associated ASG for a minimum capacity > 0
- Analyze task scheduling patterns to confirm periods of inactivity
- Correlate EC2 uptime with lack of ECS service or task activity
How to fix
4 ways to remove the waste.
- Configure an ECS Capacity Provider for the cluster and attach a target tracking scaling policy
- Set the ASG minimum capacity to 0 to allow scale-down during idle periods
- Ensure ECS services are configured with appropriate scaling triggers (e.g., CPU or memory utilization)
- Monitor for unintended delays when new tasks are scheduled to validate scaling responsiveness
Documentation
Vendor references for pricing and configuration.