Instance lifecycle in a group

When a Capacity Reservation in a group changes state, the impact on your running instances depends on the reservation type.

On-Demand Capacity Reservations

When an On-Demand Capacity Reservation in a group is canceled, expires, or has its capacity reduced, instances that target the group match with any other On-Demand Capacity Reservation in the group that has matching attributes (instance type, platform, Availability Zone, and tenancy) and available capacity. If the group does not have an On-Demand Capacity Reservation with matching attributes and available capacity, the instances run using On-Demand capacity. If you add a matching On-Demand Capacity Reservation to the group later, Amazon EC2 automatically moves the instances into its reserved capacity.

Interruptible Capacity Reservations

When the capacity of an interruptible Capacity Reservation is reclaimed, instances receive an interruption notice 2 minutes before termination. For more information, see Interruption experience.

Capacity Blocks

Instances running in a Capacity Block in a Capacity Reservation Resource Group are terminated before the Capacity Block ends, the same as for a Capacity Block that you target directly. For more information, see How Amazon EC2 Capacity Blocks work.