# DescribeClusterExtension
<a name="API_DescribeClusterExtension"></a>

Retrieves information about an extension installed on a SageMaker HyperPod cluster. The information includes the extension's version, configuration, and status, and a summary of how many cluster nodes are running the current version and configuration of the extension. If the extension has problems on some nodes, the response also lists the problems and how many nodes each one affects.

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

```
{
   "ClusterArn": "{{string}}",
   "ExtensionArn": "{{string}}"
}
```

## Request Parameters
<a name="API_DescribeClusterExtension_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.

 ** [ClusterArn](#API_DescribeClusterExtension_RequestSyntax) **   <a name="sagemaker-DescribeClusterExtension-request-ClusterArn"></a>
The Amazon Resource Name (ARN) of the SageMaker HyperPod cluster on which the extension is installed.  
Type: String  
Length Constraints: Minimum length of 0. Maximum length of 256.  
Pattern: `arn:aws[a-z\-]*:sagemaker:[a-z0-9\-]*:[0-9]{12}:cluster/[a-z0-9]{12}`   
Required: Yes

 ** [ExtensionArn](#API_DescribeClusterExtension_RequestSyntax) **   <a name="sagemaker-DescribeClusterExtension-request-ExtensionArn"></a>
The Amazon Resource Name (ARN) of the extension to describe. `CreateClusterExtension` returns this ARN, and `ListClusterExtensions` lists it. If you delete an extension and create it again, the new extension has a new ARN.  
Type: String  
Length Constraints: Minimum length of 1. Maximum length of 256.  
Pattern: `arn:aws[a-z\-]*:sagemaker:[a-z0-9\-]*:[0-9]{12}:extension/(sagemaker|eks|pcs)-[a-z0-9-]+/[a-z0-9-]+/[a-z0-9]+`   
Required: Yes

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

```
{
   "ExtensionDetails": { 
      "ClusterArn": "string",
      "ConfigurationValues": "string",
      "CreationTime": number,
      "ExtensionArn": "string",
      "ExtensionName": "string",
      "ExtensionVersion": "string",
      "LastModifiedTime": number,
      "Status": "string"
   },
   "Health": { 
      "Issues": [ 
         { 
            "Code": "string",
            "Message": "string",
            "NodeCount": number
         }
      ]
   },
   "NodeSummary": { 
      "ActiveCount": number,
      "TotalCount": number
   }
}
```

## Response Elements
<a name="API_DescribeClusterExtension_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.

 ** [ExtensionDetails](#API_DescribeClusterExtension_ResponseSyntax) **   <a name="sagemaker-DescribeClusterExtension-response-ExtensionDetails"></a>
The details of the extension.  
Type: [ExtensionDetails](API_ExtensionDetails.md) object

 ** [Health](#API_DescribeClusterExtension_ResponseSyntax) **   <a name="sagemaker-DescribeClusterExtension-response-Health"></a>
The problems that affect the extension on the cluster's nodes, grouped by cause, with the number of nodes that each problem affects. Use it to find out why `ActiveCount` is lower than `TotalCount`, or why the status is `Degraded`, `CreateFailed`, or `UpdateFailed`. SageMaker HyperPod omits `Health` when no node has a problem. Nodes where SageMaker HyperPod hasn't finished installing or updating the extension aren't counted in any issue, unless an earlier attempt failed on them.  
Type: [ExtensionHealth](API_ExtensionHealth.md) object

 ** [NodeSummary](#API_DescribeClusterExtension_ResponseSyntax) **   <a name="sagemaker-DescribeClusterExtension-response-NodeSummary"></a>
A summary of how many nodes in your cluster the extension targets, and how many of them run the extension's current version and configuration.  
Type: [ExtensionNodeSummary](API_ExtensionNodeSummary.md) object

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

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

 ** ResourceNotFound **   
Resource being access is not found.  
HTTP Status Code: 400

## See Also
<a name="API_DescribeClusterExtension_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/sagemaker-2017-07-24/DescribeClusterExtension) 
+  [AWS SDK for .NET V4](https://docs.aws.amazon.com/goto/DotNetSDKV4/sagemaker-2017-07-24/DescribeClusterExtension) 
+  [AWS SDK for C\+\+](https://docs.aws.amazon.com/goto/SdkForCpp/sagemaker-2017-07-24/DescribeClusterExtension) 
+  [AWS SDK for Go v2](https://docs.aws.amazon.com/goto/SdkForGoV2/sagemaker-2017-07-24/DescribeClusterExtension) 
+  [AWS SDK for Java V2](https://docs.aws.amazon.com/goto/SdkForJavaV2/sagemaker-2017-07-24/DescribeClusterExtension) 
+  [AWS SDK for JavaScript V3](https://docs.aws.amazon.com/goto/SdkForJavaScriptV3/sagemaker-2017-07-24/DescribeClusterExtension) 
+  [AWS SDK for Kotlin](https://docs.aws.amazon.com/goto/SdkForKotlin/sagemaker-2017-07-24/DescribeClusterExtension) 
+  [AWS SDK for PHP V3](https://docs.aws.amazon.com/goto/SdkForPHPV3/sagemaker-2017-07-24/DescribeClusterExtension) 
+  [AWS SDK for Python (Boto3)](https://docs.aws.amazon.com/goto/boto3/sagemaker-2017-07-24/DescribeClusterExtension) 
+  [AWS SDK for Ruby V3](https://docs.aws.amazon.com/goto/SdkForRubyV3/sagemaker-2017-07-24/DescribeClusterExtension)