# Create a Spot Fleet
Using the AWS Management Console, you can quickly create a Spot Fleet request by choosing only an AMI and your desired total target capacity. Amazon EC2 will configure a fleet that best meets your needs and follows Spot best practices. Alternatively, you can modify any of the default settings.
If you want to include On-Demand Instances in your fleet, you must specify a launch template in your request and specify you desired On-Demand capacity.
The fleet launches On-Demand Instances when capacity is available, and launches Spot Instances when your maximum price exceeds the Spot price and capacity is available.
If your fleet includes Spot Instances and is of type `maintain`, Amazon EC2 will attempt to maintain your fleet target capacity when your Spot Instances are interrupted.
**Required permissions**
For more information, see [Spot Fleet permissions](spot-fleet-prerequisites.md).
**Topics**
+ [
## Quickly create a Spot Fleet request
](#create-spot-fleet-quick)
+ [
## Create a Spot Fleet request using defined parameters
](#create-spot-fleet-advanced)
+ [
## Create a Spot Fleet that replaces unhealthy Spot Instances
](#spot-fleet-health-checks)
## Quickly create a Spot Fleet request
Follow these steps to quickly create a Spot Fleet request using the Amazon EC2 console.
**To create a Spot Fleet request using the recommended settings**
1. Open the Amazon EC2 console at [https://console.aws.amazon.com/ec2/](https://console.aws.amazon.com/ec2/).
1. In the navigation pane, choose **Spot Requests**.
1. If you are new to Spot, you see a welcome page; choose **Get started**. Otherwise, choose **Create Spot Fleet Request**.
1. Under **Launch parameters**, choose **Manually configure launch parameters**.
1. For **AMI**, choose an AMI.
1. Under **Target capacity**, for **Total target capacity**, specify the number of units to request. For the type of unit, you can choose **Instances**, **vCPUs**, or **Memory (GiB)**.
1. Under **Your fleet request at a glance**, review your fleet configuration, and choose **Launch**.
## Create a Spot Fleet request using defined parameters
You can create a Spot Fleet by using parameters that you define.
------
#### [ Console ]
**To create a Spot Fleet request using defined parameters**
1. Open the Amazon EC2 console at [https://console.aws.amazon.com/ec2/](https://console.aws.amazon.com/ec2/).
1. In the navigation pane, choose **Spot Requests**.
1. If you are new to Spot, you see a welcome page; choose **Get started**. Otherwise, choose **Create Spot Fleet Request**.
1. For **Launch parameters**, you can either manually configure the launch parameters or you can use a launch template, as follows:
1. [Manually configure] To define the launch parameters in the Amazon EC2 console, choose **Manually configure launch parameters**, and then do the following:
1. For **AMI**, choose one of the basic AMIs provided by AWS, or choose **Search for AMI** to use an AMI from our user community, the AWS Marketplace, or one of your own.
**Note**
If an AMI specified in the launch parameters is deregistered or disabled, no new instances can be launched from the AMI. For fleets that are set to maintain target capacity, the target capacity will not be maintained.
1. (Optional) For **Key pair name**, choose an existing key pair or create a new one.
[Existing key pair] Choose the key pair.
[New key pair] Choose **Create new key pair** to go the **Key pairs** page. When you are done, return to the **Spot Requests** page and refresh the list.
1. (Optional) Expand **Additional launch parameters**, and do the following:
1. (Optional) To enable Amazon EBS optimization, for **EBS-optimized**, select **Launch EBS-optimized instances**.
1. (Optional) To add temporary block-level storage for your instances, for **Instance store**, choose **Attach at launch**.
1. (Optional) To add storage, choose **Add new volume**, and specify additional instance store volumes or Amazon EBS volumes, depending on the instance type.
1. (Optional) By default, basic monitoring is enabled for your instances. To enable detailed monitoring, for **Monitoring**, select **Enable CloudWatch detailed monitoring**.
1. (Optional) To run a Dedicated Spot Instance, for **Tenancy**, choose **Dedicated - run a dedicated instance**.
1. (Optional) For **Security groups**, choose one or more security groups or create a new one.
[Existing security group] Choose one or more security groups.
[New security group] Choose **Create new security group** to go the **Security Groups** page. When you are done, return to the **Spot Requests** and refresh the list.
1. (Optional) To make your instances reachable from the internet, for **Auto-assign IPv4 Public IP**, choose **Enable**.
1. (Optional) To launch your Spot Instances with an IAM role, for **IAM instance profile**, choose the role.
1. (Optional) To run a start-up script, copy it to **User data**.
1. (Optional) To add a tag, choose **Create tag** and enter the key and value for the tag, and choose **Create**. Repeat for each tag.
For each tag, to tag the instances and the Spot Fleet request with the same tag, ensure that both **Instances** and **Fleet** are selected. To tag only the instances launched by the fleet, clear **Fleet**. To tag only the Spot Fleet request, clear **Instances**.
1. [Launch template] To use a configuration you created in a launch template, choose **Use a launch template**, and for **Launch template**, choose a launch template.
**Note**
If you want On-Demand capacity in your Spot Fleet, you must specify a launch template.
1. For **Additional request details**, do the following:
1. Review the additional request details. To make changes, clear **Apply defaults**.
1. (Optional) For **IAM fleet role**, you can use the default role or choose a different role. To use the default role after changing the role, choose **Use default role**.
1. (Optional) To create a request that is valid only during a specific time period, edit **Request valid from** and **Request valid until**.
1. (Optional) By default, Amazon EC2 terminates your Spot Instances when the Spot Fleet request expires. To keep them running after your request expires, clear **Terminate the instances when the request expires**.
1. (Optional) To register your Spot Instances with a load balancer, choose **Receive traffic from one or more load balancers** and choose one or more Classic Load Balancers or target groups.
1. For **Target capacity**, do the following:
1. For **Total target capacity**, specify the number of units to request. For the type of unit, you can choose **Instances**, **vCPUs**, or **Memory (MiB)**. To specify a target capacity of 0 so that you can add capacity later, you must first select **Maintain target capacity**.
1. (Optional) For **Include On-Demand base capacity**, specify the number of On-Demand units to request. The number must be less than the **Total target capacity**. Amazon EC2 calculates the difference, and allocates the difference to Spot units to request.
**Important**
To specify optional On-Demand capacity, you must first choose a launch template.
1. (Optional) By default, Amazon EC2 terminates Spot Instances when they are interrupted. To maintain the target capacity, select **Maintain target capacity**. You can then specify that Amazon EC2 terminates, stops, or hibernates Spot Instances when they are interrupted. To do so, choose the corresponding option from **Interruption behavior**.
**Note**
If an AMI specified in the launch parameters is deregistered or disabled, no new instances can be launched from the AMI. In this case, for fleets that are set to maintain target capacity, the target capacity will not be maintained.
1. (Optional) To allow Spot Fleet to launch a replacement Spot Instance when an instance rebalance notification is emitted for an existing Spot Instance in the fleet, select **Capacity rebalance**, and then choose an instance replacement strategy. If you choose **Launch before terminate**, specify the delay (in seconds) before Amazon EC2 terminates the old instances. For more information, see [Use Capacity Rebalancing in EC2 Fleet and Spot Fleet to replace at-risk Spot Instances](ec2-fleet-capacity-rebalance.md).
1. (Optional) To control the amount you pay per hour for all the Spot Instances in your fleet, select **Set maximum cost for Spot Instances** and then enter the maximum total amount you're willing to pay per hour. When the maximum total amount is reached, Spot Fleet stops launching Spot Instances even if it hasn’t met the target capacity. For more information, see [Set a spending limit for your EC2 Fleet or Spot Fleet](ec2-fleet-control-spending.md).
1. For **Network**, do the following:
1. For **Network**, choose an existing VPC or create a new one.
[Existing VPC] Choose the VPC.
[New VPC] Choose **Create new VPC** to go the Amazon VPC console. When you're done, return to this screen and refresh the list.
1. (Optional) For **Availability Zone**, let Amazon EC2 choose the Availability Zones for your Spot Instances, or specify one or more Availability Zones.
If you have more than one subnet in an Availability Zone, choose the appropriate subnet from **Subnet**. To add subnets, choose **Create new subnet** to go to the Amazon VPC console. When you are done, return to this screen and refresh the list.
1. For **Instance type requirements**, you can either specify instance attributes and let Amazon EC2 identify the optimal instance types with these attributes, or you can specify a list of instances. For more information, see [Specify attributes for instance type selection for EC2 Fleet or Spot Fleet](ec2-fleet-attribute-based-instance-type-selection.md).
1. If you choose **Specify instance attributes that match your compute requirements**, specify your instance attributes as follows:
1. For **vCPUs**, enter the desired minimum and maximum number of vCPUs. To specify no limit, select **No minimum** or **No maximum**, or both.
1. For **Memory (GiB)**, enter the desired minimum and maximum amount of memory. To specify no limit, select **No minimum** or **No maximum**, or both.
1. (Optional) For **Additional instance attribute**, you can optionally specify one or more attributes to express your compute requirements in more detail. Each additional attribute adds a further constraint to your request. You can omit the additional attributes; when omitted, the default values are used. For a description of each attribute and their default values, see [get-spot-placement-scores](https://docs.aws.amazon.com/cli/latest/reference/ec2/get-spot-placement-scores.html).
1. (Optional) To view the instance types with your specified attributes, expand **Preview matching instance types**. To exclude instance types from being used in your request, select the instances and then choose **Exclude selected instance types**.
1. If you choose **Manually select instance types**, Spot Fleet provides a default list of instance types. To select more instance types, choose **Add instance types**, select the instance types to use in your request, and choose **Select**. To delete instance types, select the instance types and choose **Delete**.
1. For **Allocation strategy**, choose a Spot allocation strategy and an On-Demand allocation strategy that meets your needs. For more information, see [Use allocation strategies to determine how EC2 Fleet or Spot Fleet fulfills Spot and On-Demand capacity](ec2-fleet-allocation-strategy.md).
1. For **Your fleet request at a glance**, review your fleet configuration, and make any adjustments if necessary.
1. (Optional) To download a copy of the launch configuration for use with the AWS CLI, choose **JSON config**.
1. When you're ready to launch your Spot Fleet, choose **Launch**.
The Spot Fleet request type is `fleet`. When the request is fulfilled, requests of type `instance` are added, where the state is `active` and the status is `fulfilled`.
------
#### [ AWS CLI ]
**To create a Spot Fleet request**
Use the [request-spot-fleet](https://docs.aws.amazon.com/cli/latest/reference/ec2/request-spot-fleet.html) command.
```
aws ec2 request-spot-fleet --spot-fleet-request-config file://config.json
```
For example configuration files, see [Example CLI configurations Spot Fleet](spot-fleet-examples.md).
------
#### [ PowerShell ]
**To create a Spot Fleet request**
Use the [Request-EC2SpotFleet](https://docs.aws.amazon.com/powershell/latest/reference/items/Request-EC2SpotFleet.html) cmdlet. The following example launches Spot Instances in a capacity-optimized fleet.
```
Request-EC2SpotFleet `
-SpotFleetRequestConfig_TargetCapacity 50 `
-SpotFleetRequestConfig_AllocationStrategy "CapacityOptimized" `
-SpotFleetRequestConfig_IamFleetRole "arn:aws:iam::123456789012:role/my-spot-fleet-role" `
-SpotFleetRequestConfig_LaunchTemplateConfig @($launchConfig)
```
Define the launch configuration as follows, setting the launch template and override properties that you need. For example configurations, see [Example CLI configurations Spot Fleet](spot-fleet-examples.md).
```
$lcSpec = Amazon.EC2.Model.FleetLaunchTemplateSpecification
# To do - Set FleetLaunchTemplateSpecification properties
$lcOverrides = New-Object Amazon.EC2.Model.LaunchTemplateOverrides
# To do - Set LaunchTemplateOverrides properties
$launchConfig = New-Object Amazon.EC2.Model.LaunchTemplateConfig
$launchConfig.LaunchTemplateSpecification $lcSpec
$launchConfig.Overrides @($lcOverrides)
```
------
## Create a Spot Fleet that replaces unhealthy Spot Instances
Spot Fleet checks the health status of the Spot Instances in the fleet every two minutes. The health status of an instance is either `healthy` or `unhealthy`.
Spot Fleet determines the health status of an instance by using the status checks provided by Amazon EC2. An instance is determined as `unhealthy` when the status of either the instance status check or the system status check is `impaired` for three consecutive health checks. For more information, see [Status checks for Amazon EC2 instances](monitoring-system-instance-status-check.md).
You can configure your fleet to replace unhealthy Spot Instances. After enabling health check replacement, a Spot Instance is replaced when it is reported as `unhealthy`. The fleet could go below its target capacity for up to a few minutes while an unhealthy Spot Instance is being replaced.
**Requirements**
+ Health check replacement is supported only for Spot Fleets that maintain a target capacity (fleets of type `maintain`), not for one-time Spot Fleets (fleets of type `request`).
+ Health check replacement is supported only for Spot Instances. This feature is not supported for On-Demand Instances.
+ You can configure your Spot Fleet to replace unhealthy instances only when you create it.
+ Users can use health check replacement only if they have permission to call the `ec2:DescribeInstanceStatus` action.
------
#### [ Console ]
**To configure a Spot Fleet to replace unhealthy Spot Instances**
1. Follow the steps for creating a Spot Fleet in [Create a Spot Fleet request using defined parameters](#create-spot-fleet-advanced).
1. To configure the fleet to replace unhealthy Spot Instances, expand **Additional launch parameters**, and under **Health check**, select **Replace unhealthy instances**. To enable this option, you must first choose **Maintain target capacity**.
------
#### [ AWS CLI ]
**To configure a Spot Fleet to replace unhealthy Spot Instances**
Use the [request-spot-fleet](https://docs.aws.amazon.com/cli/latest/reference/ec2/request-spot-fleet.html) command with the `ReplaceUnhealthyInstances` property of `SpotFleetRequestConfig`.
```
{
"SpotFleetRequestConfig": {
"AllocationStrategy": "lowestPrice",
"IamFleetRole": "arn:aws:iam::123456789012:role/aws-ec2-spot-fleet-tagging-role",
"TargetCapacity": 10,
"ReplaceUnhealthyInstances": true
}
}
```
------
#### [ PowerShell ]
**To configure a Spot Fleet request to replace unhealthy Spot Instances**
Use the [Request-EC2SpotFleet](https://docs.aws.amazon.com/powershell/latest/reference/items/Request-EC2SpotFleet.html) cmdlet with the `-SpotFleetRequestConfig_ReplaceUnhealthyInstance` parameter.
```
-SpotFleetRequestConfig_ReplaceUnhealthyInstance $true
```
------