Types of auto scaling
Two kinds of auto scaling policies are defined:
- Target tracking scaling policies
- Step scaling policies
We shall discuss these two kinds of auto scaling policy next, before demonstrating the use of auto scaling.
Target tracking scaling policies
The target being referred to is a target value for a specific metric that CloudWatch metrics monitor. The two ECS metrics CloudWatch monitors are CPU utilization and memory utilization. With target tracking scaling policies, the number of tasks is increased or decreased with the objective that the target value of a metric is kept. It may not be feasible to keep the precise target value of a metric because the number of tasks are increased/decreased in increments/decrements of 1. The metric is kept at the precise configured target value or close to the target value. A target tracking scaling policy itself adjusts itself to the fluctuations in a metric value to avoid rapid fluctuations in the number of tasks. For high application availability...
