# PurchaseReservedInstanceOffering
<a name="API_PurchaseReservedInstanceOffering"></a>

Allows you to purchase Amazon OpenSearch Service Reserved Instances.

## Request Syntax
<a name="API_PurchaseReservedInstanceOffering_RequestSyntax"></a>

```
POST /2021-01-01/opensearch/purchaseReservedInstanceOffering HTTP/1.1
Content-type: application/json

{
   "InstanceCount": number,
   "ReservationName": "string",
   "ReservedInstanceOfferingId": "string"
}
```

## URI Request Parameters
<a name="API_PurchaseReservedInstanceOffering_RequestParameters"></a>

The request does not use any URI parameters.

## Request Body
<a name="API_PurchaseReservedInstanceOffering_RequestBody"></a>

The request accepts the following data in JSON format.

 ** [InstanceCount](#API_PurchaseReservedInstanceOffering_RequestSyntax) **   <a name="opensearchservice-PurchaseReservedInstanceOffering-request-InstanceCount"></a>
The number of OpenSearch instances to reserve.  
Type: Integer  
Valid Range: Minimum value of 1.  
Required: No

 ** [ReservationName](#API_PurchaseReservedInstanceOffering_RequestSyntax) **   <a name="opensearchservice-PurchaseReservedInstanceOffering-request-ReservationName"></a>
A customer-specified identifier to track this reservation.  
Type: String  
Length Constraints: Minimum length of 5. Maximum length of 64.  
Pattern: `.*`   
Required: Yes

 ** [ReservedInstanceOfferingId](#API_PurchaseReservedInstanceOffering_RequestSyntax) **   <a name="opensearchservice-PurchaseReservedInstanceOffering-request-ReservedInstanceOfferingId"></a>
The ID of the Reserved Instance offering to purchase.  
Type: String  
Length Constraints: Fixed length of 36.  
Pattern: `\p{XDigit}{8}-\p{XDigit}{4}-\p{XDigit}{4}-\p{XDigit}{4}-\p{XDigit}{12}`   
Required: Yes

## Response Syntax
<a name="API_PurchaseReservedInstanceOffering_ResponseSyntax"></a>

```
HTTP/1.1 200
Content-type: application/json

{
   "ReservationName": "string",
   "ReservedInstanceId": "string"
}
```

## Response Elements
<a name="API_PurchaseReservedInstanceOffering_ResponseElements"></a>

If the action is successful, the service sends back an HTTP 200 response.

The following data is returned in JSON format by the service.

 ** [ReservationName](#API_PurchaseReservedInstanceOffering_ResponseSyntax) **   <a name="opensearchservice-PurchaseReservedInstanceOffering-response-ReservationName"></a>
The customer-specified identifier used to track this reservation.  
Type: String  
Length Constraints: Minimum length of 5. Maximum length of 64.  
Pattern: `.*` 

 ** [ReservedInstanceId](#API_PurchaseReservedInstanceOffering_ResponseSyntax) **   <a name="opensearchservice-PurchaseReservedInstanceOffering-response-ReservedInstanceId"></a>
The ID of the Reserved Instance offering that was purchased.  
Type: String  
Length Constraints: Fixed length of 36.  
Pattern: `\p{XDigit}{8}-\p{XDigit}{4}-\p{XDigit}{4}-\p{XDigit}{4}-\p{XDigit}{12}` 

## Errors
<a name="API_PurchaseReservedInstanceOffering_Errors"></a>

For information about the errors that are common to all actions, see [Common Error Types](CommonErrors.md).

 ** DisabledOperationException **   
An error occured because the client wanted to access an unsupported operation.  
HTTP Status Code: 409

 ** InternalException **   
Request processing failed because of an unknown error, exception, or internal failure.  
HTTP Status Code: 500

 ** LimitExceededException **   
An exception for trying to create more than the allowed number of resources or sub-resources.  
HTTP Status Code: 409

 ** ResourceAlreadyExistsException **   
An exception for creating a resource that already exists.  
HTTP Status Code: 409

 ** ResourceNotFoundException **   
An exception for accessing or deleting a resource that doesn't exist.  
HTTP Status Code: 409

 ** ValidationException **   
An exception for accessing or deleting a resource that doesn't exist.  
HTTP Status Code: 400

## See Also
<a name="API_PurchaseReservedInstanceOffering_SeeAlso"></a>

For more information about using this API in one of the language-specific AWS SDKs, see the following:
+  [AWS Command Line Interface V2](https://docs.aws.amazon.com/goto/cli2/opensearch-2021-01-01/PurchaseReservedInstanceOffering) 
+  [AWS SDK for .NET V4](https://docs.aws.amazon.com/goto/DotNetSDKV4/opensearch-2021-01-01/PurchaseReservedInstanceOffering) 
+  [AWS SDK for C\$1\$1](https://docs.aws.amazon.com/goto/SdkForCpp/opensearch-2021-01-01/PurchaseReservedInstanceOffering) 
+  [AWS SDK for Go v2](https://docs.aws.amazon.com/goto/SdkForGoV2/opensearch-2021-01-01/PurchaseReservedInstanceOffering) 
+  [AWS SDK for Java V2](https://docs.aws.amazon.com/goto/SdkForJavaV2/opensearch-2021-01-01/PurchaseReservedInstanceOffering) 
+  [AWS SDK for JavaScript V3](https://docs.aws.amazon.com/goto/SdkForJavaScriptV3/opensearch-2021-01-01/PurchaseReservedInstanceOffering) 
+  [AWS SDK for Kotlin](https://docs.aws.amazon.com/goto/SdkForKotlin/opensearch-2021-01-01/PurchaseReservedInstanceOffering) 
+  [AWS SDK for PHP V3](https://docs.aws.amazon.com/goto/SdkForPHPV3/opensearch-2021-01-01/PurchaseReservedInstanceOffering) 
+  [AWS SDK for Python](https://docs.aws.amazon.com/goto/boto3/opensearch-2021-01-01/PurchaseReservedInstanceOffering) 
+  [AWS SDK for Ruby V3](https://docs.aws.amazon.com/goto/SdkForRubyV3/opensearch-2021-01-01/PurchaseReservedInstanceOffering)