# FailoverDBCluster
<a name="API_FailoverDBCluster"></a>

Forces a failover for a DB cluster.

A failover for a DB cluster promotes one of the Read Replicas (read-only instances) in the DB cluster to be the primary instance (the cluster writer).

Amazon Neptune will automatically fail over to a Read Replica, if one exists, when the primary instance fails. You can force a failover when you want to simulate a failure of a primary instance for testing. Because each instance in a DB cluster has its own endpoint address, you will need to clean up and re-establish any existing connections that use those endpoint addresses when the failover is complete.

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

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

 ** DBClusterIdentifier **   
A DB cluster identifier to force a failover for. This parameter is not case-sensitive.  
Constraints:  
+ Must match the identifier of an existing DBCluster.
Type: String  
Required: No

 ** TargetDBInstanceIdentifier **   
The name of the instance to promote to the primary instance.  
You must specify the instance identifier for an Read Replica in the DB cluster. For example, `mydbcluster-replica1`.  
Type: String  
Required: No

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

The following element is returned by the service.

 ** DBCluster **   
Contains the details of an Amazon Neptune DB cluster.  
This data type is used as a response element in the [DescribeDBClusters](API_DescribeDBClusters.md).  
Type: [DBCluster](API_DBCluster.md) object

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

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

 ** DBClusterNotFoundFault **   
 *DBClusterIdentifier* does not refer to an existing DB cluster.  
HTTP Status Code: 404

 ** InvalidDBClusterStateFault **   
The DB cluster is not in a valid state.  
HTTP Status Code: 400

 ** InvalidDBInstanceState **   
The specified DB instance is not in the *available* state.  
HTTP Status Code: 400

## See Also
<a name="API_FailoverDBCluster_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/neptune-2014-10-31/FailoverDBCluster) 
+  [AWS SDK for .NET V4](https://docs.aws.amazon.com/goto/DotNetSDKV4/neptune-2014-10-31/FailoverDBCluster) 
+  [AWS SDK for C\$1\$1](https://docs.aws.amazon.com/goto/SdkForCpp/neptune-2014-10-31/FailoverDBCluster) 
+  [AWS SDK for Go v2](https://docs.aws.amazon.com/goto/SdkForGoV2/neptune-2014-10-31/FailoverDBCluster) 
+  [AWS SDK for Java V2](https://docs.aws.amazon.com/goto/SdkForJavaV2/neptune-2014-10-31/FailoverDBCluster) 
+  [AWS SDK for JavaScript V3](https://docs.aws.amazon.com/goto/SdkForJavaScriptV3/neptune-2014-10-31/FailoverDBCluster) 
+  [AWS SDK for Kotlin](https://docs.aws.amazon.com/goto/SdkForKotlin/neptune-2014-10-31/FailoverDBCluster) 
+  [AWS SDK for PHP V3](https://docs.aws.amazon.com/goto/SdkForPHPV3/neptune-2014-10-31/FailoverDBCluster) 
+  [AWS SDK for Python](https://docs.aws.amazon.com/goto/boto3/neptune-2014-10-31/FailoverDBCluster) 
+  [AWS SDK for Ruby V3](https://docs.aws.amazon.com/goto/SdkForRubyV3/neptune-2014-10-31/FailoverDBCluster)