Understanding Auto Scaling policies
Let's revisit the concept of scaling once more. Scaling refers to the increasing or decreasing of the compute capacity of your application. It usually starts with a scaling action or an event that tells an Auto Scaling group to either launch a new instance or terminate existing ones.
AWS provides a bunch of ways to scale your Auto Scaling group. Let's look at these scaling policies one by one:
- Scale manually: This is the most basic way to scale your resources. You only need to specify the minimum, maximum, or desired capacity of your Auto Scaling group. We used a manual scaling policy in Figure 6.14, where we manually specify the desired, minimum, and maximum capacity.
- Scale based on demand/dynamic scaling: This is an advanced scaling policy where we can define the parameter that controls our scaling process in response to changing demand. For example, so far, we only have two EC2 web instances to handle the application load...