# OnDemandOptionsRequest
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Describes the configuration of On-Demand Instances in an EC2 Fleet.

## Contents
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 ** AllocationStrategy **   
The strategy that determines the order of the launch template overrides to use in fulfilling On-Demand capacity.  
 `lowest-price` - EC2 Fleet uses price to determine the order, launching the lowest price first.  
 `prioritized` - EC2 Fleet uses the priority that you assigned to each launch template override, launching the highest priority first.  
Default: `lowest-price`   
Type: String  
Valid Values: `lowest-price | prioritized`   
Required: No

 ** CapacityReservationOptions **   
The strategy for using unused Capacity Reservations for fulfilling On-Demand capacity.  
Supported only for fleets of type `instant`.  
Type: [CapacityReservationOptionsRequest](API_CapacityReservationOptionsRequest.md) object  
Required: No

 ** MaxTotalPrice **   
The maximum amount per hour for On-Demand Instances that you're willing to pay.  
If your fleet includes T instances that are configured as `unlimited`, and if their average CPU usage exceeds the baseline utilization, you will incur a charge for surplus credits. The `MaxTotalPrice` does not account for surplus credits, and, if you use surplus credits, your final cost might be higher than what you specified for `MaxTotalPrice`. For more information, see [Surplus credits can incur charges](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/burstable-performance-instances-unlimited-mode-concepts.html#unlimited-mode-surplus-credits) in the *Amazon EC2 User Guide*.
Type: String  
Required: No

 ** MinTargetCapacity **   
The minimum target capacity for On-Demand Instances in the fleet. If this minimum capacity isn't reached, no instances are launched.  
Constraints: Maximum value of `1000`. Supported only for fleets of type `instant`.  
At least one of the following must be specified: `SingleAvailabilityZone` \$1 `SingleInstanceType`   
Type: Integer  
Required: No

 ** SingleAvailabilityZone **   
Indicates that the fleet launches all On-Demand Instances into a single Availability Zone.  
Supported only for fleets of type `instant`.  
Type: Boolean  
Required: No

 ** SingleInstanceType **   
Indicates that the fleet uses a single instance type to launch all On-Demand Instances in the fleet.  
Supported only for fleets of type `instant`.  
Type: Boolean  
Required: No

## See Also
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For more information about using this API in one of the language-specific AWS SDKs, see the following:
+  [AWS SDK for C\$1\$1](https://docs.aws.amazon.com/goto/SdkForCpp/ec2-2016-11-15/OnDemandOptionsRequest) 
+  [AWS SDK for Java V2](https://docs.aws.amazon.com/goto/SdkForJavaV2/ec2-2016-11-15/OnDemandOptionsRequest) 
+  [AWS SDK for Ruby V3](https://docs.aws.amazon.com/goto/SdkForRubyV3/ec2-2016-11-15/OnDemandOptionsRequest)