# DescribeFlywheelIteration
<a name="API_DescribeFlywheelIteration"></a>

Retrieve the configuration properties of a flywheel iteration. For more information about flywheels, see [ Flywheel overview](https://docs.aws.amazon.com/comprehend/latest/dg/flywheels-about.html) in the *Amazon Comprehend Developer Guide*.

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

```
{
   "FlywheelArn": "string",
   "FlywheelIterationId": "string"
}
```

## Request Parameters
<a name="API_DescribeFlywheelIteration_RequestParameters"></a>

For information about the parameters that are common to all actions, see [Common Parameters](CommonParameters.md).

The request accepts the following data in JSON format.

 ** [FlywheelArn](#API_DescribeFlywheelIteration_RequestSyntax) **   <a name="comprehend-DescribeFlywheelIteration-request-FlywheelArn"></a>
  
Type: String  
Length Constraints: Maximum length of 256.  
Pattern: `arn:aws(-[^:]+)?:comprehend:[a-zA-Z0-9-]*:[0-9]{12}:flywheel/[a-zA-Z0-9](-*[a-zA-Z0-9])*`   
Required: Yes

 ** [FlywheelIterationId](#API_DescribeFlywheelIteration_RequestSyntax) **   <a name="comprehend-DescribeFlywheelIteration-request-FlywheelIterationId"></a>
  
Type: String  
Length Constraints: Maximum length of 63.  
Pattern: `[0-9]{8}T[0-9]{6}Z`   
Required: Yes

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

```
{
   "FlywheelIterationProperties": { 
      "CreationTime": number,
      "EndTime": number,
      "EvaluatedModelArn": "string",
      "EvaluatedModelMetrics": { 
         "AverageAccuracy": number,
         "AverageF1Score": number,
         "AveragePrecision": number,
         "AverageRecall": number
      },
      "EvaluationManifestS3Prefix": "string",
      "FlywheelArn": "string",
      "FlywheelIterationId": "string",
      "Message": "string",
      "Status": "string",
      "TrainedModelArn": "string",
      "TrainedModelMetrics": { 
         "AverageAccuracy": number,
         "AverageF1Score": number,
         "AveragePrecision": number,
         "AverageRecall": number
      }
   }
}
```

## Response Elements
<a name="API_DescribeFlywheelIteration_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.

 ** [FlywheelIterationProperties](#API_DescribeFlywheelIteration_ResponseSyntax) **   <a name="comprehend-DescribeFlywheelIteration-response-FlywheelIterationProperties"></a>
The configuration properties of a flywheel iteration.  
Type: [FlywheelIterationProperties](API_FlywheelIterationProperties.md) object

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

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

 ** InternalServerException **   
An internal server error occurred. Retry your request.  
HTTP Status Code: 500

 ** InvalidRequestException **   
The request is invalid.    
 ** Detail **   
Provides additional detail about why the request failed.
HTTP Status Code: 400

 ** ResourceNotFoundException **   
The specified resource ARN was not found. Check the ARN and try your request again.  
HTTP Status Code: 400

 ** TooManyRequestsException **   
The number of requests exceeds the limit. Resubmit your request later.  
HTTP Status Code: 400

## See Also
<a name="API_DescribeFlywheelIteration_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/comprehend-2017-11-27/DescribeFlywheelIteration) 
+  [AWS SDK for .NET V4](https://docs.aws.amazon.com/goto/DotNetSDKV4/comprehend-2017-11-27/DescribeFlywheelIteration) 
+  [AWS SDK for C\$1\$1](https://docs.aws.amazon.com/goto/SdkForCpp/comprehend-2017-11-27/DescribeFlywheelIteration) 
+  [AWS SDK for Go v2](https://docs.aws.amazon.com/goto/SdkForGoV2/comprehend-2017-11-27/DescribeFlywheelIteration) 
+  [AWS SDK for Java V2](https://docs.aws.amazon.com/goto/SdkForJavaV2/comprehend-2017-11-27/DescribeFlywheelIteration) 
+  [AWS SDK for JavaScript V3](https://docs.aws.amazon.com/goto/SdkForJavaScriptV3/comprehend-2017-11-27/DescribeFlywheelIteration) 
+  [AWS SDK for Kotlin](https://docs.aws.amazon.com/goto/SdkForKotlin/comprehend-2017-11-27/DescribeFlywheelIteration) 
+  [AWS SDK for PHP V3](https://docs.aws.amazon.com/goto/SdkForPHPV3/comprehend-2017-11-27/DescribeFlywheelIteration) 
+  [AWS SDK for Python](https://docs.aws.amazon.com/goto/boto3/comprehend-2017-11-27/DescribeFlywheelIteration) 
+  [AWS SDK for Ruby V3](https://docs.aws.amazon.com/goto/SdkForRubyV3/comprehend-2017-11-27/DescribeFlywheelIteration)