Note: To perform this exercise, you need at least one EC2 instance running and with AWS Cost Explorer and Amazon EC2 Resource Optimization enabled.
The first step to choosing the correct EC2 size is to monitor and analyze current service users to gain insight into the performance of virtual machines and the patterns in use. To collect enough data, it is necessary to observe usage over a period of at least 2 weeks (ideally 1 month) to understand workload and peak periods. The most common metrics used to determine virtual machine performance are vPCU, memory, network, and disk usage.