This is the new *CloudFormation Template Reference Guide*. Please update your bookmarks and links. For help getting started with CloudFormation, see the [AWS CloudFormation User Guide](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/Welcome.html).

# AWS::EMR::InstanceGroupConfig
<a name="aws-resource-emr-instancegroupconfig"></a>

Use `InstanceGroupConfig` to define instance groups for an EMR cluster. A cluster can not use both instance groups and instance fleets. For more information, see [Create a Cluster with Instance Fleets or Uniform Instance Groups](https://docs.aws.amazon.com//emr/latest/ManagementGuide/emr-instance-group-configuration.html) in the *Amazon EMR Management Guide*.

**Important**  
You can currently only add task instance groups to a cluster with this resource. If you use this resource, CloudFormation waits for the cluster launch to complete before adding the task instance group to the cluster. In order to add task instance groups to the cluster as part of the cluster launch and minimize delays in provisioning task nodes, use the `TaskInstanceGroups` subproperty for the [AWS::EMR::Cluster JobFlowInstancesConfig](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-elasticmapreduce-cluster-jobflowinstancesconfig.html) property instead. To use this subproperty, see [AWS::EMR::Cluster](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-elasticmapreduce-cluster.html) for examples.

## Syntax
<a name="aws-resource-emr-instancegroupconfig-syntax"></a>

To declare this entity in your CloudFormation template, use the following syntax:

### JSON
<a name="aws-resource-emr-instancegroupconfig-syntax.json"></a>

```
{
  "Type" : "AWS::EMR::InstanceGroupConfig",
  "Properties" : {
      "[AutoScalingPolicy](#cfn-emr-instancegroupconfig-autoscalingpolicy)" : AutoScalingPolicy,
      "[BidPrice](#cfn-emr-instancegroupconfig-bidprice)" : String,
      "[Configurations](#cfn-emr-instancegroupconfig-configurations)" : [ Configuration, ... ],
      "[CustomAmiId](#cfn-emr-instancegroupconfig-customamiid)" : String,
      "[EbsConfiguration](#cfn-emr-instancegroupconfig-ebsconfiguration)" : EbsConfiguration,
      "[InstanceCount](#cfn-emr-instancegroupconfig-instancecount)" : Integer,
      "[InstanceRole](#cfn-emr-instancegroupconfig-instancerole)" : String,
      "[InstanceType](#cfn-emr-instancegroupconfig-instancetype)" : String,
      "[JobFlowId](#cfn-emr-instancegroupconfig-jobflowid)" : String,
      "[Market](#cfn-emr-instancegroupconfig-market)" : String,
      "[Name](#cfn-emr-instancegroupconfig-name)" : String
    }
}
```

### YAML
<a name="aws-resource-emr-instancegroupconfig-syntax.yaml"></a>

```
Type: AWS::EMR::InstanceGroupConfig
Properties:
  [AutoScalingPolicy](#cfn-emr-instancegroupconfig-autoscalingpolicy): 
    AutoScalingPolicy
  [BidPrice](#cfn-emr-instancegroupconfig-bidprice): String
  [Configurations](#cfn-emr-instancegroupconfig-configurations): 
    - Configuration
  [CustomAmiId](#cfn-emr-instancegroupconfig-customamiid): String
  [EbsConfiguration](#cfn-emr-instancegroupconfig-ebsconfiguration): 
    EbsConfiguration
  [InstanceCount](#cfn-emr-instancegroupconfig-instancecount): Integer
  [InstanceRole](#cfn-emr-instancegroupconfig-instancerole): String
  [InstanceType](#cfn-emr-instancegroupconfig-instancetype): String
  [JobFlowId](#cfn-emr-instancegroupconfig-jobflowid): String
  [Market](#cfn-emr-instancegroupconfig-market): String
  [Name](#cfn-emr-instancegroupconfig-name): String
```

## Properties
<a name="aws-resource-emr-instancegroupconfig-properties"></a>

`AutoScalingPolicy`  <a name="cfn-emr-instancegroupconfig-autoscalingpolicy"></a>
`AutoScalingPolicy` is a subproperty of `InstanceGroupConfig`. `AutoScalingPolicy` defines how an instance group dynamically adds and terminates EC2 instances in response to the value of a CloudWatch metric. For more information, see [Using Automatic Scaling in Amazon EMR](https://docs.aws.amazon.com//emr/latest/ManagementGuide/emr-automatic-scaling.html) in the *Amazon EMR Management Guide*.  
*Required*: No  
*Type*: [AutoScalingPolicy](aws-properties-emr-instancegroupconfig-autoscalingpolicy.md)  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`BidPrice`  <a name="cfn-emr-instancegroupconfig-bidprice"></a>
If specified, indicates that the instance group uses Spot Instances. This is the maximum price you are willing to pay for Spot Instances. Specify `OnDemandPrice` to set the amount equal to the On-Demand price, or specify an amount in USD.  
*Required*: No  
*Type*: String  
*Pattern*: `[\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*`  
*Minimum*: `0`  
*Maximum*: `256`  
*Update requires*: [Replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

`Configurations`  <a name="cfn-emr-instancegroupconfig-configurations"></a>
Amazon EMR releases 4.x or later.
The list of configurations supplied for an Amazon EMR cluster instance group. You can specify a separate configuration for each instance group (master, core, and task).  
*Required*: No  
*Type*: Array of [Configuration](aws-properties-emr-instancegroupconfig-configuration.md)  
*Update requires*: [Replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

`CustomAmiId`  <a name="cfn-emr-instancegroupconfig-customamiid"></a>
The custom AMI ID to use for the provisioned instance group.  
*Required*: No  
*Type*: String  
*Pattern*: `[\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*`  
*Minimum*: `0`  
*Maximum*: `256`  
*Update requires*: [Replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

`EbsConfiguration`  <a name="cfn-emr-instancegroupconfig-ebsconfiguration"></a>
`EbsConfiguration` determines the EBS volumes to attach to EMR cluster instances.  
*Required*: No  
*Type*: [EbsConfiguration](aws-properties-emr-instancegroupconfig-ebsconfiguration.md)  
*Update requires*: [Replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

`InstanceCount`  <a name="cfn-emr-instancegroupconfig-instancecount"></a>
Target number of instances for the instance group.  
*Required*: Yes  
*Type*: Integer  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`InstanceRole`  <a name="cfn-emr-instancegroupconfig-instancerole"></a>
The role of the instance group in the cluster.  
*Allowed Values*: TASK  
*Required*: Yes  
*Type*: String  
*Update requires*: [Replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

`InstanceType`  <a name="cfn-emr-instancegroupconfig-instancetype"></a>
The Amazon EC2 instance type for all instances in the instance group.  
*Required*: Yes  
*Type*: String  
*Pattern*: `[\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*`  
*Minimum*: `1`  
*Maximum*: `256`  
*Update requires*: [Replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

`JobFlowId`  <a name="cfn-emr-instancegroupconfig-jobflowid"></a>
The ID of an Amazon EMR cluster that you want to associate this instance group with.  
*Required*: Yes  
*Type*: String  
*Update requires*: [Replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

`Market`  <a name="cfn-emr-instancegroupconfig-market"></a>
Market type of the Amazon EC2 instances used to create a cluster node.  
*Required*: No  
*Type*: String  
*Allowed values*: `ON_DEMAND | SPOT`  
*Update requires*: [Replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

`Name`  <a name="cfn-emr-instancegroupconfig-name"></a>
Friendly name given to the instance group.  
*Required*: No  
*Type*: String  
*Pattern*: `[\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*`  
*Minimum*: `0`  
*Maximum*: `256`  
*Update requires*: [Replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

## Return values
<a name="aws-resource-emr-instancegroupconfig-return-values"></a>

### Ref
<a name="aws-resource-emr-instancegroupconfig-return-values-ref"></a>

When you pass the logical ID of this resource to the intrinsic `Ref` function, `Ref` returns returns the ID of the instance group.

For more information about using the `Ref` function, see [https://docs.aws.amazon.com/AWSCloudFormation/latest/TemplateReference/intrinsic-function-reference-ref.html](https://docs.aws.amazon.com/AWSCloudFormation/latest/TemplateReference/intrinsic-function-reference-ref.html).

### Fn::GetAtt
<a name="aws-resource-emr-instancegroupconfig-return-values-fn--getatt"></a>

## Examples
<a name="aws-resource-emr-instancegroupconfig--examples"></a>

Example instance group configuration specifications.

**Topics**
+ [Add a task instance group](#aws-resource-emr-instancegroupconfig--examples--Add_a_task_instance_group)
+ [Specify an Automatic Scaling Policy](#aws-resource-emr-instancegroupconfig--examples--Specify_an_Automatic_Scaling_Policy)

### Add a task instance group
<a name="aws-resource-emr-instancegroupconfig--examples--Add_a_task_instance_group"></a>

The following example adds a task instance group to a cluster named `TestCluster`.

#### JSON
<a name="aws-resource-emr-instancegroupconfig--examples--Add_a_task_instance_group--json"></a>

```
"TestInstanceGroupConfig": {
    "Type": "AWS: : EMR: : InstanceGroupConfig",
    "Properties": {
        "InstanceCount": 2,
        "InstanceType": "m3.xlarge",
        "InstanceRole": "TASK",
        "Market": "ON_DEMAND",
        "Name": "cfnTask2",
        "JobFlowId": {
            "Ref": "cluster"
        }
    }
}
```

#### YAML
<a name="aws-resource-emr-instancegroupconfig--examples--Add_a_task_instance_group--yaml"></a>

```
TestInstanceGroupConfig: 
  Properties: 
    InstanceCount: 2
    InstanceRole: TASK
    InstanceType: m3.xlarge
    JobFlowId: 
      Ref: cluster
    Market: ON_DEMAND
    Name: cfnTask2
  Type: "AWS::EMR::InstanceGroupConfig"
```

### Specify an Automatic Scaling Policy
<a name="aws-resource-emr-instancegroupconfig--examples--Specify_an_Automatic_Scaling_Policy"></a>

The following example defines an `AutoScalingPolicy` for an `InstanceGroupConfig` resource.

#### JSON
<a name="aws-resource-emr-instancegroupconfig--examples--Specify_an_Automatic_Scaling_Policy--json"></a>

```
"MyInstanceGroupConfig": {
  "Type": "AWS::EMR::InstanceGroupConfig",
  "Properties": {
    "InstanceCount": 1,
    "InstanceType": {
      "Ref": "InstanceType"
    },
    "InstanceRole": "TASK",
    "Market": "ON_DEMAND",
    "Name": "cfnTask",
    "JobFlowId": {
      "Ref": "MyCluster"
    },
    "AutoScalingPolicy": {
      "Constraints": {
        "MinCapacity": {
          "Ref": "MinCapacity"
        },
        "MaxCapacity": {
          "Ref": "MaxCapacity"
        }
      },
      "Rules": [
        {
          "Name": "Scale-out",
          "Description": "Scale-out policy",
          "Action": {
            "SimpleScalingPolicyConfiguration": {
              "AdjustmentType": "CHANGE_IN_CAPACITY",
              "ScalingAdjustment": 1,
              "CoolDown": 300
            }
          },
          "Trigger": {
            "CloudWatchAlarmDefinition": {
              "Dimensions": [
                {
                  "Key": "JobFlowId",
                  "Value": "${emr.clusterId}"
                }
              ],
              "EvaluationPeriods": 1,
              "Namespace": "AWS/ElasticMapReduce",
              "Period": 300,
              "ComparisonOperator": "LESS_THAN",
              "Statistic": "AVERAGE",
              "Threshold": 15,
              "Unit": "PERCENT",
              "MetricName": "YARNMemoryAvailablePercentage"
            }
          }
        },
        {
          "Name": "Scale-in",
          "Description": "Scale-in policy",
          "Action": {
            "SimpleScalingPolicyConfiguration": {
              "AdjustmentType": "CHANGE_IN_CAPACITY",
              "ScalingAdjustment": -1,
              "CoolDown": 300
            }
          },
          "Trigger": {
            "CloudWatchAlarmDefinition": {
              "Dimensions": [
                {
                  "Key": "JobFlowId",
                  "Value": "${emr.clusterId}"
                }
              ],
              "EvaluationPeriods": 1,
              "Namespace": "AWS/ElasticMapReduce",
              "Period": 300,
              "ComparisonOperator": "GREATER_THAN",
              "Statistic": "AVERAGE",
              "Threshold": 75,
              "Unit": "PERCENT",
              "MetricName": "YARNMemoryAvailablePercentage"
            }
          }
        }
      ]
    }
  }
}
```

#### YAML
<a name="aws-resource-emr-instancegroupconfig--examples--Specify_an_Automatic_Scaling_Policy--yaml"></a>

```
MyInstanceGroupConfig:
  Type: 'AWS::EMR::InstanceGroupConfig'
  Properties:
    InstanceCount: 1
    InstanceType: !Ref InstanceType
    InstanceRole: TASK
    Market: ON_DEMAND
    Name: cfnTask
    JobFlowId: !Ref MyCluster
    AutoScalingPolicy:
      Constraints:
        MinCapacity: !Ref MinCapacity
        MaxCapacity: !Ref MaxCapacity
      Rules:
        - Name: Scale-out
          Description: Scale-out policy
          Action:
            SimpleScalingPolicyConfiguration:
              AdjustmentType: CHANGE_IN_CAPACITY
              ScalingAdjustment: 1
              CoolDown: 300
          Trigger:
            CloudWatchAlarmDefinition:
              Dimensions:
                - Key: JobFlowId
                  Value: '${emr.clusterId}'
              EvaluationPeriods: 1
              Namespace: AWS/ElasticMapReduce
              Period: 300
              ComparisonOperator: LESS_THAN
              Statistic: AVERAGE
              Threshold: 15
              Unit: PERCENT
              MetricName: YARNMemoryAvailablePercentage
        - Name: Scale-in
          Description: Scale-in policy
          Action:
            SimpleScalingPolicyConfiguration:
              AdjustmentType: CHANGE_IN_CAPACITY
              ScalingAdjustment: -1
              CoolDown: 300
          Trigger:
            CloudWatchAlarmDefinition:
              Dimensions:
                - Key: JobFlowId
                  Value: '${emr.clusterId}'
              EvaluationPeriods: 1
              Namespace: AWS/ElasticMapReduce
              Period: 300
              ComparisonOperator: GREATER_THAN
              Statistic: AVERAGE
              Threshold: 75
              Unit: PERCENT
              MetricName: YARNMemoryAvailablePercentage
```