Why does the EC2 Instance Hours report shows instances running for more hours than available in a month?

Products

• CloudHealth

Issue/Introduction

When you launch an EC2 instance, it first enters the pending state and then transitions to the running state. When you stop that instance, it first enters the stopping state and then transitions to the stopped state.

Each time an instance transitions from stopped to running, AWS charges for a full instance hour, even if these transitions happen multiple times within a single hour.

Therefore, if you restart an EC2 instance multiple times in an hour, each restart incurs an hour of usage. When these restarts occur consistently throughout a month, the instance usage hours tend to exceed the total available hours in that month.

For more information, see EC2 Instance Lifecycle.