EMR Spark allows users to configure the amount of Memory and CPU cores that it will utilize. However, tuning these values has until now been a manual process for customers that can be complex. For instance, too little memory can result in out-of-memory exceptions but allocating too much can result in over-spending on idle resources. Vertical autoscaling automatically scales the memory and CPU allocated to an EMR Spark application based on its real-time and historic resource utilization. This simplifies the process of tuning resources and optimizing costs for an application while helping improve its reliability.