The EC2 Resource Utilization Heat Map displays the average CPU utilization, by hour, for all of your EC2 instances over the last 7 days. It provides a visual representation of when, and how much, your instances are being utilized.
There are several options available within the report:
Show for all instances – generates the heat map using the average CPU utilization for all EC2 instances.
Show for specific instance – generates the heat map using the average CPU utilization for an individual EC2 instance (selected in the dropdown).
Map colors by Absolute terms (0-100%) – generates the heat map where 0% is the lowest utilization percentage, and represented by dark blue in the map. And dark red is represented by 100%, the highest utilization percentage. Anything that falls in between will be colored accordingly.
Map colors by Relative terms – generates the heat map where the lowest recorded CPU utilization will be represented by dark blue in the map, and the highest recorded CPU utilization will be dark red.
Show percents in squares – with this option enabled, the heat map will display the recorded CPU utilization within the heat map itself. With it disabled, you can still hover your mouse over the squares on the heat map to see their CPU utilization percentage.
The colored squares in the heat map represent the average CPU utilization for that hour of time. Dark blue is the lowest, white is the middle, and dark red is the highest average CPU utilization.