[
    {
        "InstanceGroupType": "MASTER",
        "InstanceCount": 1,
        "Name": "Master Instance Group",
        "InstanceType": "m1.large"
    },
    {
        "InstanceGroupType": "CORE",
        "InstanceCount": 2,
        "Name": "Core Instance Group",
        "InstanceType": "m1.xlarge"
    },
    {
        "InstanceGroupType": "TASK",
        "InstanceCount": 3,
        "Name": "Task Instance Group",
        "BidPrice": "3.45",
        "InstanceType": "m1.xlarge"
    }
]