Domain 4 - Design Cost-Optimized Architectures

Question 1

Ways to optimize EBS for cost

Answer 1

1. Right-size EBS volumes
2. Choose the appropriate volume type
3. Use services like Trusted Advisor
4. Delete old EBS snapshots

Question 2

After reviewing the cost optimization checks in Trusted Advisor, a team finds that it has 10,000 EBS snapshots in its account that are more than 30 days old. the team has determined that it needs to implement better governance for the lifecycle of its resources. Which actions should the team take to automate the lifecycle management of the EBS snapshots with the LEAST effort? (Select TWO)

A: Create and schedule a backup plan with AWS Backup
B: Copy the EBS snapshots to S3, then create lifecycle configurations in the S3 bucket
C: Use Amazon Data Lifecycle Manager (Amazon DLM)
D: Use a scheduled even in Amazon EventBridge (Amazon CloudWatch Events) and invoke AWS Step Functions to manage the snapshots
E: Schedule and run backups in AWS Systems Manager

Answer 2

A: Correct. Will automate the taking of snapshots.
B: Wrong. Works, but lots of manual effort.
C: Correct. Automate the deletion of old snapshots.
D: Wrong. StepFunctions can’t handle the snapshots without code being manually written to make that work
E: Wrong. More effort than AWS Backup and DLM

Question 3

EC2 Pricing Models

Answer 3

On-demand
Reserved 
Dedicated
Spot
Savings Plans

Question 4

A startup company is looking for a solution to cost-effectively run and access micro-services without the operational overhead of managing infrastructure. The solution needs to be able to scale quickly to accommodate rapid changes in the volume of requests and protect against common DDoS attacks. What is the MOST cost-effective solution that meets these requirements?

A: Run the micro-services in containers using Elastic Beanstalk
B: Run the micro-services in Lambda behind and API Gateway
C: Run the micro-services on EC2 in an auto scaling group
D: Run the micro-services in containers using ECS backed by EC2 instances

Answer 4

A: Wrong. Beanstalk is scalable, but it isn’t fast since it uses EC2. Also not very cost effective since there could be idling resources.
B: Correct.
C: Wrong. Same reasons as A.
D: Wrong. Same reasons as A and C.

Question 5

A company is developing an app that runs on EC2 in a private subnet. The EC2 instance uses a NAT gateway to access the internet. An SA must provide a secure option so that developers can log into the instances. Which solution meets these requirements MOST cost-effectively?

A: Configure AWS Systems Manager Session Manager for the EC2 instances to enable login.
B: Configure a bastion host in a public subnet to log in to the EC2 instances in a private subnet
C: Use the existing NAT gateway to log into the EC2 in a private subnet
D: Configure AWS Site-to-Site VPN to log in directly to the EC2

Answer 5

A: Correct. No additional charge. Doesn’t need to open any additional ports.
B: Wrong. Works, but bastion hosts cost money
C: Wrong. NAT gateways don’t allow inbound traffic.
D: Wrong. Works, but VPNs cost money