Describes the strategy for using unused Capacity Reservations for fulfilling On-Demand capacity.
This strategy can only be used if the EC2 Fleet is of type
For more information about Capacity Reservations, see On-Demand Capacity Reservations in the Amazon Elastic Compute Cloud User Guide. For examples of using Capacity Reservations in an EC2 Fleet, see EC2 Fleet Example Configurations in the Amazon Elastic Compute Cloud User Guide.
Indicates whether to use unused Capacity Reservations for fulfilling On-Demand capacity.
If you specify
use-capacity-reservations-first, the fleet uses unused Capacity Reservations to fulfill On-Demand capacity up to the target On-Demand capacity. If multiple instance pools have unused Capacity Reservations, the On-Demand allocation strategy (
prioritized) is applied. If the number of unused Capacity Reservations is less than the On-Demand target capacity, the remaining On-Demand target capacity is launched according to the On-Demand allocation strategy (
If you do not specify a value, the fleet fulfils the On-Demand capacity according to the chosen On-Demand allocation strategy.