Amazon Elastic MapReduce
API Reference (API Version 2009-03-31)

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ModifyInstanceGroups modifies the number of nodes and configuration settings of an instance group. The input parameters include the new target instance count for the group and the instance group ID. The call will either succeed or fail atomically.

Request Syntax

{ "ClusterId": "string", "InstanceGroups": [ { "Configurations": [ { "Classification": "string", "Configurations": [ "Configuration" ], "Properties": { "string" : "string" } } ], "EC2InstanceIdsToTerminate": [ "string" ], "InstanceCount": number, "InstanceGroupId": "string", "ShrinkPolicy": { "DecommissionTimeout": number, "InstanceResizePolicy": { "InstancesToProtect": [ "string" ], "InstancesToTerminate": [ "string" ], "InstanceTerminationTimeout": number } } } ] }

Request Parameters

For information about the parameters that are common to all actions, see Common Parameters.

The request accepts the following data in JSON format.


The ID of the cluster to which the instance group belongs.

Type: String

Required: No


Instance groups to change.

Type: Array of InstanceGroupModifyConfig objects

Required: No

Response Elements

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


For information about the errors that are common to all actions, see Common Errors.


Indicates that an error occurred while processing the request and that the request was not completed.

HTTP Status Code: 400


Sample Request

POST / HTTP/1.1 Content-Type: application/x-amz-json-1.1 X-Amz-Target: ElasticMapReduce.ModifyInstanceGroups Content-Length: 77 User-Agent: aws-sdk-ruby/1.9.2 ruby/1.9.3 i386-mingw32 Host: X-Amz-Date: 20130716T205843Z X-Amz-Content-Sha256: bb1af3d0c6c6a1a09f21ccd7f04a0e2e6c9ce5b5810b0f6777560fe4f81bda8c Authorization: AWS4-HMAC-SHA256 Credential=AKIAIOSFODNN7EXAMPLE/20130716/us-east-1/elasticmapreduce/aws4_request, SignedHeaders=content-length;content-type;host;user-agent;x-amz-content-sha256;x-amz-date;x-amz-target, Signature=17bbbb4448a1f47a14d5657445e9de5cadf16bed58b850585f80865882133b33 Accept: */* {"InstanceGroups": [{ "InstanceGroupId": "ig-1S8NWT31S2OVG", "InstanceCount": 5 }]}

Sample Response

HTTP/1.1 200 OK x-amzn-RequestId: 80a74808-ee5a-11e2-90db-69a5154aeb8d Content-Type: application/x-amz-json-1.1 Content-Length: 0 Date: Tue, 16 Jul 2013 20:58:44 GMT

See Also

For more information about using this API in one of the language-specific AWS SDKs, see the following: