[
    {
        "InstanceGroupType": "MASTER",
        "InstanceCount": 1,
        "Name": "Master Instance Group",
        "InstanceType": "d2.xlarge",
        "EbsConfiguration":
                {"EbsBlockDeviceConfigs":
                        [	
                        	{"VolumeSpecification":
	                            {"VolumeType": "standard",
	                             "SizeInGB": 10},
                             "VolumesPerInstance": 4}
                        ],
                 "EbsOptimized": true}
    },
    {
        "InstanceGroupType": "CORE",
        "InstanceCount": 2,
        "Name": "Core Instance Group",
        "InstanceType": "d2.xlarge"
    },
    {
        "InstanceGroupType": "TASK",
        "InstanceCount": 3,
        "Name": "Task Instance Group",
        "BidPrice": "3.45",
        "InstanceType": "d2.xlarge"
    }
]
