Service Limits

The total scope of the AWS cloud is vast. It’s hard to even visualize just how much compute and storage capacity is available for its customers. And the scalability of its design means that there shouldn’t be a practical ceiling on how much infrastructure any customer is able to access on demand.

Nevertheless, for various reasons, AWS imposes limits on the scope of resources you can use. That’s why if you don’t properly plan ahead, your service requests might sometimes push your share of AWS resources past your account limit and fail.

So, for instance, you’re allowed to run only 20 on-demand and 20 reserved instances of the EC2 m5.large instance type at any one time within a single AWS Region. Other instance types are limited to similar maximums. This would seem to reflect Amazon’s desire to ensure that all classes of resources should be reliably available to meet new demand and not all held by a few large customers. But it...