How do min_instance and min_idle_instance affect app engine autoscaling?

[Yating Li]

I understand the number of instances may also be affected by traffic and other flags. 

So ideally which one of the attached pic shows the mechanism of app engine autoscaling if only min_instance and min_idle_instance are counted?

Assumption 1 is based on this formular : numTotalInstances = max(min_instances, min_idle_instances + needed_instance_count) [1], 

If it's correct, can I believe that when min_instance is smaller than min_idle_instances, min_instance is no longer a factor can affect total number of instance (since min_idle_instances + needed_instance_count is always bigger)?

[1]https://medium.com/google-cloud/app-engine-resident-instances-and-the-startup-time-problem-8c6587040a80

[Jose Antonio Soni Solchaga]

Hello, 

I see that image 2 explains it better as it is clear the instances that were just added and the instances that just got traffic. 

As an improvement I would add the description in the top part for the red  ones that they are active, and give enough space for the text not to be in two rows as borrowed in the first column.