Metric your cluster will track in order to scale in and out. For example, CPU_UTILIZATION_PERCENTAGE is the average CPU usage across all nodes in a cluster.
Desired value of chosen auto_scaling_metric. When metric drops below this value, cluster will scale in. When metric goes above this value, cluster will scale out. Can be set between 0 and 100 percent.
Lowest number of nodes to scale. Must be at least 1 and less than the max_node_count. If nodes in cluster belong to multiple availability zones, then min_node_count must be at least 3.