Issue
Normally my monthly consumptions go from 25 to 30 dollars but these last two months it has doubled and reviewing the concepts I can see the following, do you know the reason for this if no change has been made?
Solution
It would appear that your T3a burstable instance used more CPU credits than it accrued, so was charged for the excess credits consumed.
The credits concept can be quite confusing, but I think you can avoid this from happening if you deactivate the Unlimited option.
From Key concepts and definitions for burstable performance instances - Amazon Elastic Compute Cloud:
Unlimited mode: Credit configuration mode, which allows an instance to burst above the baseline by sustaining high CPU utilization for any period of time whenever required. The hourly instance price automatically covers all CPU usage spikes if the average CPU utilization of the instance is at or below the baseline over a rolling 24-hour period or the instance lifetime, whichever is shorter. If the instance runs at higher CPU utilization for a prolonged period, it can do so for a flat additional rate per vCPU-hour.
Answered By - John Rotenstein Answer Checked By - Robin (WPSolving Admin)