Exam AWS Certified Solutions Architect - Associate SAA-C02 topic 1 question 295 discussion

D: auto-scaling with target tracking

Answer is D. Reason is within the url: https://docs.aws.amazon.com/AmazonECS/latest/developerguide/service-autoscaling-targettracking.html With target tracking scaling policies, you select a metric and set a target value. Amazon ECS Service Auto Scaling creates and manages the CloudWatch alarms that trigger the scaling policy and calculates the scaling adjustment based on the metric and the target value. The scaling policy adds or removes service tasks as required to keep the metric at, or close to, the specified target value. In addition to keeping the metric close to the target value, a target tracking scaling policy also adjusts to the fluctuations in the metric due to a fluctuating load pattern and minimizes rapid fluctuations in the number of tasks running in your service.

The answer is D Target tracking scaling helps to improve application availability and reduce costs. For example, you can use Auto Scaling to automatically launch EC2 instances for your Auto Scaling group when demand increases to help maintain performance, and terminate instances when demand drops to save money. https://aws.amazon.com/about-aws/whats-new/2017/07/introducing-target-tracking-scaling-policies-for-auto-scaling/

why not lambda?

Fargate so D

Agree with D

Recall that in case of ECS ,scaling applies for service/application as well as underlying instance. ECS ahs 2 launch types-EC2(based on servers to manage) or Fargate(no EC2s to manage) Here, Fargate means no EC2 to maanage or scale,so A and C are out. B -Lambda is not needed to scale D fits.

https://docs.aws.amazon.com/autoscaling/application/userguide/what-is-application-auto-scaling.html: "Application Auto Scaling is a web service for developers and system administrators who need a solution for automatically scaling their scalable resources for individual AWS services beyond Amazon EC2. Application Auto Scaling allows you to configure automatic scaling for the following resources: AppStream 2.0 fleets Aurora replicas Amazon Comprehend document classification and entity recognizer endpoints DynamoDB tables and global secondary indexes Amazon Elastic Container Service (ECS) services" Answer is D

Ans=D. Use AWS Application Auto Scaling with target tracking policies to scale when ECS metric breaches trigger an Amazon CloudWatch alarm.

And use the Fargate option on ECS which means it doesn´t use EC2 instances. So it´s D

Why the website indicates A as a correct answer when it's clearly D?

D. ECS with Fargate launch type supports autoscaling with target tracking.

D is the answer https://docs.aws.amazon.com/AmazonECS/latest/developerguide/service-autoscaling-targettracking.html

Auto Scaling with target tracking ::D

should be D

D https://docs.aws.amazon.com/AmazonECS/latest/developerguide/service-auto-scaling.html Amazon ECS Service Auto Scaling supports the following types of automatic scaling: 1. Target Tracking Scaling Policies 2. Step Scaling Policies 3. Scheduled Scaling

Its D for sure