Sign in

v1

latestOpenAPI 3.0.0Apache 2.0 License2026-07-171,1822,9897.4 MB

Creates a Spot Fleet request.

The Spot Fleet request specifies the total target capacity and the On-Demand target capacity. Amazon EC2 calculates the difference between the total capacity and On-Demand capacity, and launches the difference as Spot capacity.

You can submit a single request that includes multiple launch specifications that vary by instance type, AMI, Availability Zone, or subnet.

By default, the Spot Fleet requests Spot Instances in the Spot Instance pool where the price per unit is the lowest. Each launch specification can include its own instance weighting that reflects the value of the instance type to your application workload.

Alternatively, you can specify that the Spot Fleet distribute the target capacity across the Spot pools included in its launch specifications. By ensuring that the Spot Instances in your Spot Fleet are in different Spot pools, you can improve the availability of your fleet.

You can specify tags for the Spot Fleet request and instances launched by the fleet. You cannot tag other resource types in a Spot Fleet request because only the spot-fleet-request and instance resource types are supported.

For more information, see Spot Fleet requests in the Amazon EC2 User Guide.

We strongly discourage using the RequestSpotFleet API because it is a legacy API with no planned investment. For options for requesting Spot Instances, see Which is the best Spot request method to use? in the Amazon EC2 User Guide.

get/#Action=RequestSpotFleet

Query parameters

DryRunboolean

Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.

AllocationStrategy'lowestPrice' | 'diversified' | 'capacityOptimized' | 'capacityOptimizedPrioritized' | 'priceCapacityOptimized'
<p>The strategy that determines how to allocate the target Spot Instance capacity across the Spot Instance pools specified by the Spot Fleet launch configuration. For more information, see <a href="https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/spot-fleet-allocation-strategy.html">Allocation strategies for Spot Instances</a> in the <i>Amazon EC2 User Guide</i>.</p> <dl> <dt>priceCapacityOptimized (recommended)</dt> <dd> <p>Spot Fleet identifies the pools with the highest capacity availability for the number of instances that are launching. This means that we will request Spot Instances from the pools that we believe have the lowest chance of interruption in the near term. Spot Fleet then requests Spot Instances from the lowest priced of these pools.</p> </dd> <dt>capacityOptimized</dt> <dd> <p>Spot Fleet identifies the pools with the highest capacity availability for the number of instances that are launching. This means that we will request Spot Instances from the pools that we believe have the lowest chance of interruption in the near term. To give certain instance types a higher chance of launching first, use <code>capacityOptimizedPrioritized</code>. Set a priority for each instance type by using the <code>Priority</code> parameter for <code>LaunchTemplateOverrides</code>. You can assign the same priority to different <code>LaunchTemplateOverrides</code>. EC2 implements the priorities on a best-effort basis, but optimizes for capacity first. <code>capacityOptimizedPrioritized</code> is supported only if your Spot Fleet uses a launch template. Note that if the <code>OnDemandAllocationStrategy</code> is set to <code>prioritized</code>, the same priority is applied when fulfilling On-Demand capacity.</p> </dd> <dt>diversified</dt> <dd> <p>Spot Fleet requests instances from all of the Spot Instance pools that you specify.</p> </dd> <dt>lowestPrice</dt> <dd> <p>Spot Fleet requests instances from the lowest priced Spot Instance pool that has available capacity. If the lowest priced pool doesn't have available capacity, the Spot Instances come from the next lowest priced pool that has available capacity. If a pool runs out of capacity before fulfilling your desired capacity, Spot Fleet will continue to fulfill your request by drawing from the next lowest priced pool. To ensure that your desired capacity is met, you might receive Spot Instances from several pools. Because this strategy only considers instance price and not capacity availability, it might lead to high interruption rates.</p> </dd> </dl> <p>Default: <code>lowestPrice</code> </p>
OnDemandAllocationStrategy'lowestPrice' | 'prioritized'

The order of the launch template overrides to use in fulfilling On-Demand capacity. If you specify <code>lowestPrice</code>, Spot Fleet uses price to determine the order, launching the lowest price first. If you specify <code>prioritized</code>, Spot Fleet uses the priority that you assign to each Spot Fleet launch template override, launching the highest priority first. If you do not specify a value, Spot Fleet defaults to <code>lowestPrice</code>.

ClientTokenstring

A unique, case-sensitive identifier that you provide to ensure the idempotency of your listings. This helps to avoid duplicate listings. For more information, see <a href="https://docs.aws.amazon.com/AWSEC2/latest/APIReference/Run_Instance_Idempotency.html">Ensuring Idempotency</a>.

ExcessCapacityTerminationPolicy'noTermination' | 'default'
<p>Indicates whether running instances should be terminated if you decrease the target capacity of the Spot Fleet request below the current size of the Spot Fleet.</p> <p>Supported only for fleets of type <code>maintain</code>.</p>
FulfilledCapacitynumber double

The number of units fulfilled by this request compared to the set target capacity. You cannot set this value.

OnDemandFulfilledCapacitynumber double

The number of On-Demand units fulfilled by this request compared to the set target On-Demand capacity.

IamFleetRolestring required

The Amazon Resource Name (ARN) of an Identity and Access Management (IAM) role that grants the Spot Fleet the permission to request, launch, terminate, and tag instances on your behalf. For more information, see <a href="https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/spot-fleet-requests.html#spot-fleet-prerequisites">Spot Fleet prerequisites</a> in the <i>Amazon EC2 User Guide</i>. Spot Fleet can terminate Spot Instances on your behalf when you cancel its Spot Fleet request using <a href="https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_CancelSpotFleetRequests">CancelSpotFleetRequests</a> or when the Spot Fleet request expires, if you set <code>TerminateInstancesWithExpiration</code>.

SpotPricestring
<p>The maximum price per unit hour that you are willing to pay for a Spot Instance. We do not recommend using this parameter because it can lead to increased interruptions. If you do not specify this parameter, you will pay the current Spot price.</p> <important> <p>If you specify a maximum price, your instances will be interrupted more frequently than if you do not specify this parameter.</p> </important>
TargetCapacityinteger required

The number of units to request for the Spot Fleet. You can choose to set the target capacity in terms of instances or a performance characteristic that is important to your application workload, such as vCPUs, memory, or I/O. If the request type is <code>maintain</code>, you can specify a target capacity of 0 and add capacity later.

OnDemandTargetCapacityinteger

The number of On-Demand units to request. You can choose to set the target capacity in terms of instances or a performance characteristic that is important to your application workload, such as vCPUs, memory, or I/O. If the request type is <code>maintain</code>, you can specify a target capacity of 0 and add capacity later.

OnDemandMaxTotalPricestring

The maximum amount per hour for On-Demand Instances that you're willing to pay. You can use the <code>onDemandMaxTotalPrice</code> parameter, the <code>spotMaxTotalPrice</code> parameter, or both parameters to ensure that your fleet cost does not exceed your budget. If you set a maximum price per hour for the On-Demand Instances and Spot Instances in your request, Spot Fleet will launch instances until it reaches the maximum amount you're willing to pay. When the maximum amount you're willing to pay is reached, the fleet stops launching instances even if it hasn’t met the target capacity.

SpotMaxTotalPricestring

The maximum amount per hour for Spot Instances that you're willing to pay. You can use the <code>spotdMaxTotalPrice</code> parameter, the <code>onDemandMaxTotalPrice</code> parameter, or both parameters to ensure that your fleet cost does not exceed your budget. If you set a maximum price per hour for the On-Demand Instances and Spot Instances in your request, Spot Fleet will launch instances until it reaches the maximum amount you're willing to pay. When the maximum amount you're willing to pay is reached, the fleet stops launching instances even if it hasn’t met the target capacity.

TerminateInstancesWithExpirationboolean

Indicates whether running Spot Instances are terminated when the Spot Fleet request expires.

Type'request' | 'maintain' | 'instant'

The type of request. Indicates whether the Spot Fleet only requests the target capacity or also attempts to maintain it. When this value is <code>request</code>, the Spot Fleet only places the required requests. It does not attempt to replenish Spot Instances if capacity is diminished, nor does it submit requests in alternative Spot pools if capacity is not available. When this value is <code>maintain</code>, the Spot Fleet maintains the target capacity. The Spot Fleet places the required requests to meet capacity and automatically replenishes any interrupted instances. Default: <code>maintain</code>. <code>instant</code> is listed but is not used by Spot Fleet.

ValidFromstring date-time

The start date and time of the request, in UTC format (<i>YYYY</i>-<i>MM</i>-<i>DD</i>T<i>HH</i>:<i>MM</i>:<i>SS</i>Z). By default, Amazon EC2 starts fulfilling the request immediately.

ValidUntilstring date-time

The end date and time of the request, in UTC format (<i>YYYY</i>-<i>MM</i>-<i>DD</i>T<i>HH</i>:<i>MM</i>:<i>SS</i>Z). After the end date and time, no new Spot Instance requests are placed or able to fulfill the request. If no value is specified, the Spot Fleet request remains until you cancel it.

ReplaceUnhealthyInstancesboolean

Indicates whether Spot Fleet should replace unhealthy instances.

InstanceInterruptionBehavior'hibernate' | 'stop' | 'terminate'

The behavior when a Spot Instance is interrupted. The default is <code>terminate</code>.

InstancePoolsToUseCountinteger
<p>The number of Spot pools across which to allocate your target Spot capacity. Valid only when Spot <b>AllocationStrategy</b> is set to <code>lowest-price</code>. Spot Fleet selects the cheapest Spot pools and evenly allocates your target Spot capacity across the number of Spot pools that you specify.</p> <p>Note that Spot Fleet attempts to draw Spot Instances from the number of pools that you specify on a best effort basis. If a pool runs out of Spot capacity before fulfilling your target capacity, Spot Fleet will continue to fulfill your request by drawing from the next cheapest pool. To ensure that your target capacity is met, you might receive Spot Instances from more than the number of pools that you specified. Similarly, if most of the pools have no Spot capacity, you might receive your full target capacity from fewer than the number of pools that you specified.</p>
Contextstring

Reserved.

TargetCapacityUnitType'vcpu' | 'memory-mib' | 'units'
<p>The unit for the target capacity. <code>TargetCapacityUnitType</code> can only be specified when <code>InstanceRequirements</code> is specified.</p> <p>Default: <code>units</code> (translates to number of instances)</p>

The configuration for the Spot Fleet request.

Action'RequestSpotFleet' required
Version'2016-11-15' required

Response

Success