In the AWS Billing section of Chapter 11, Highly-Available Cloud Infrastructure on AWS, we covered the monthly costs of operating a web server, ranging from $5/month to $45/month, from a single-server instance scenario to a highly-available infrastructure. For most needs, budgeting discussions will begin and end with this monthly number. You can execute load tests, as suggested in the Advanced Load Testing section, to predict your per server user capacity and get a general idea of how many servers you may need. In a dynamically scaling cloud environment with dozens of servers running 24/7, this is an overly simplistic way to calculate a budget.
If you operate a web property of any significant scale, things get invariably complicated. You will be operating multiple servers on different tech stacks, serving different purposes. It can be difficult to gauge or...