Exam AWS Certified Solutions Architect - Associate SAA-C02 topic 1 question 200 discussion

D is correct as the SLA is based on the age of the message.

Agreee with D

C. Create an Amazon Machine image (AMI) from the instance used for processing. Create an Auto Scaling group using this image in its launch configuration. Configure the group with a target tracking policy to keep its aggregate CPU utilization below 70%. By creating an AMI from the existing instance and configuring an Auto Scaling group with a target tracking policy based on CPU utilization, the system can automatically scale out by launching additional instances when the CPU utilization exceeds the threshold. This ensures that the system can handle increased load by dynamically adding resources as needed to meet performance requirements. Additionally, using a target tracking policy based on CPU utilization is a common approach for scaling applications as it provides a simple and effective way to manage resource allocation based on system demand.

Option D suggests creating an Auto Scaling group with a target tracking policy based on the age of the oldest message in the SQS queue. While this approach might seem intuitive, it may not be the most effective way to scale the processing infrastructure. Using the age of the oldest message in the SQS queue as a scaling metric could lead to unpredictable scaling behavior. For example, if there is a sudden spike in message processing time due to a temporary increase in workload or an unexpected issue, the scaling action triggered by the age of the oldest message may not be able to respond quickly enough to address the performance degradation. D - is not correct

C is the right answer can configure ASG based on CPU Utilization

Agreed with D

D - thanks that many agree on this too

A&B clearly wrong as they don't "manage any level of load". Between C&D: Being I/O intensive (assume disk I/O here), CPU usage could still be quite low but the queue is getting very long as it is disk I/O constrained, not CPU constrained, so it wouldn't scale up with C. Makes D correct

D is correct as the SLA is based on the age of the message.

Answer is D. SLA hampered due to no of messages/ageing messages ,use this instead of CPU to track (C vs D) Only concern is whether the custom metric is supported in the first place? A does not do any dynamic scaling, not a feasible option over C/D. B has no relevance /dedicated instance implies its launched on a host reserved for the organization(cannot control placement). Does not help address the rise in message volume. Organisation may not even have this option purchased.

D makes the most sense obviously. This solution isn't part of any of the given answers --- but wouldnt a FIFO address the issue and meet SLA requirement?

D. Create an Amazon Machine Image (AMI) from the instance used for processing. Create an Auto Scaling group using this image in its launch configuration. Configure the group with a target tracking policy based on the age of the oldest message in the SQS queue. D. Create an Amazon Machine Image (AMI) from the instance used for processing. Create an Auto Scaling group using this image in its launch configuration. Configure the group with a target tracking policy based on the age of the oldest message in the SQS queue.

Answer D but have limitations with AWS Management Console to get custom metrics Limitations and prerequisites To use this configuration, you need to be aware of the following limitations: You must use the AWS CLI or an SDK to publish your custom metric to CloudWatch. You can then monitor your metric with the AWS Management Console. After publishing your custom metric, you must use the AWS CLI or an SDK to create a target tracking scaling policy with a customized metric specification. https://docs.aws.amazon.com/autoscaling/ec2/userguide/as-using-sqs-queue.html

Correct Answer is D

A and B are definitely wrong; both do not address the qn of meeting SLA of "maximum amount of time that can elapse" C is also wrong; why 70% and not another metric level percentage? Answer is D

Answer is D for sure. https://docs.aws.amazon.com/autoscaling/ec2/userguide/as-using-sqs-queue.html

Answer=D