What is the cause of the error and how can it be corrected?
AWS does not currently have enough capacity to service the request for that instance type. A different Availability Zone or instance type must be used.
The account has reached its concurrent running instance limit. An EC2 limit increase request must be filed with AWS Support.
The APIs that service the EC2 requests have received too many requests and capacity has been reached. The request should be attempted again in a few minutes.
The Administrator did not specify the correct size of the instance to support the capacity requirements of the workload. Select a bigger instance.
Explanations:
The “InsufficientInstanceCapacity” error occurs when AWS does not have enough capacity available to fulfill the request for that specific instance type. Changing the Availability Zone or instance type resolves this issue.
This error is not related to an account’s running instance limit, but rather to the lack of available capacity for the requested instance type.
This error is not caused by too many requests to the EC2 API; it’s related to the physical capacity of the availability zone. The request will not necessarily succeed by retrying later.
The instance size is not the issue here. The error is due to lack of capacity for the requested instance type, not because the instance size was incorrect.
From my perspective, the answer is:
AWS does not currently have enough capacity to service the request for that instance type. A different Availability Zone or instance type must be used.