T2 Credits
I’ve now been using an Amazon “t2.nano” EC2 instance for my web hosting. These are designed to allow “Burstable Performance”. Amazon has a few different descriptions from the simplistic:
T2 instances accrue CPU Credits when they are idle, and use CPU credits when they are active.
to a much more detailed explanation.
The later document says that the credits are processed at millisecond resolution. But, the free monitoring tools only sample at 5-minute granularity, so it is difficult to see anything of finer granularity than that.