# Placement


Describes the placement of an instance.

## Contents


 ** Affinity ** (request), ** affinity ** (response)  
The affinity setting for the instance on the Dedicated Host.  
This parameter is not supported for [CreateFleet](https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_CreateFleet) or [ImportInstance](https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_ImportInstance.html).  
Type: String  
Required: No

 ** AvailabilityZone ** (request), ** availabilityZone ** (response)  
The Availability Zone of the instance.  
On input, you can specify `AvailabilityZone` or `AvailabilityZoneId`, but not both. If you specify neither one, Amazon EC2 automatically selects an Availability Zone for you.  
This parameter is not supported for [CreateFleet](https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_CreateFleet).  
Type: String  
Required: No

 ** AvailabilityZoneId ** (request), ** availabilityZoneId ** (response)  
The ID of the Availability Zone of the instance.  
On input, you can specify `AvailabilityZone` or `AvailabilityZoneId`, but not both. If you specify neither one, Amazon EC2 automatically selects an Availability Zone for you.  
This parameter is not supported for [CreateFleet](https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_CreateFleet).  
Type: String  
Required: No

 ** GroupId ** (request), ** groupId ** (response)  
The ID of the placement group that the instance is in.  
On input, you can specify `GroupId` or `GroupName`, but not both.  
Type: String  
Required: No

 ** GroupName ** (request), ** groupName ** (response)  
The name of the placement group that the instance is in.  
On input, you can specify `GroupId` or `GroupName`, but not both.  
Type: String  
Required: No

 ** HostId ** (request), ** hostId ** (response)  
The ID of the Dedicated Host on which the instance resides.  
This parameter is not supported for [CreateFleet](https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_CreateFleet) or [ImportInstance](https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_ImportInstance.html).  
Type: String  
Required: No

 ** HostResourceGroupArn ** (request), ** hostResourceGroupArn ** (response)  
The ARN of the host resource group in which to launch the instances.  
On input, if you specify this parameter, either omit the **Tenancy** parameter or set it to `host`.  
This parameter is not supported for [CreateFleet](https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_CreateFleet).  
Type: String  
Required: No

 ** PartitionNumber ** (request), ** partitionNumber ** (response)  
The number of the partition that the instance is in. Valid only if the placement group strategy is set to `partition`.  
This parameter is not supported for [CreateFleet](https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_CreateFleet).  
Type: Integer  
Required: No

 ** SpreadDomain ** (request), ** spreadDomain ** (response)  
Reserved for future use.  
Type: String  
Required: No

 ** Tenancy ** (request), ** tenancy ** (response)  
The tenancy of the instance. An instance with a tenancy of `dedicated` runs on single-tenant hardware.  
This parameter is not supported for [CreateFleet](https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_CreateFleet). The `host` tenancy is not supported for [ImportInstance](https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_ImportInstance.html) or for T3 instances that are configured for the `unlimited` CPU credit option.  
Type: String  
Valid Values: `default | dedicated | host`   
Required: No

## See Also


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/Placement) 
+  [AWS SDK for Java V2](https://docs.aws.amazon.com/goto/SdkForJavaV2/ec2-2016-11-15/Placement) 
+  [AWS SDK for Ruby V3](https://docs.aws.amazon.com/goto/SdkForRubyV3/ec2-2016-11-15/Placement)