SOA-C02 Cost and Performance Optimization Practice Test 10 — 15 Questions

Question 1

A company wants to optimize costs for its Amazon EC2 instances. Which TWO strategies are effective for reducing costs?

Accepted Answer

Use Spot Instances for fault-tolerant workloads.. Using Spot Instances for fault-tolerant workloads can reduce costs significantly (up to 90%). Rightsizing instances ensures you are not paying for unused capacity. Dedicated Hosts increase costs. Increasing provisioned IOPS increases costs. Using EBS General Purpose SSD (gp3) is cost-effective but not a primary cost reduction strategy.

Answer

Increase the provisioned IOPS for EBS volumes.

Answer

Use EBS General Purpose SSD (gp2) volumes instead of gp3.

Answer

Use Dedicated Hosts to meet compliance requirements.

Question 2

A company runs a web application on EC2 instances in an Auto Scaling group. The application experiences variable traffic. The company wants to improve performance and reduce costs. Which THREE actions should the company take?

Accepted Answer

Implement dynamic scaling policies based on CPU utilization.. Using a mix of On-Demand and Spot Instances balances cost and reliability. Implementing dynamic scaling based on CPU utilization ensures capacity matches demand. Using an ELB with connection draining helps maintain performance during scale-in. Increasing instance size increases cost. Reducing the number of instances may cause performance issues.

Answer

Reduce the number of instances in the Auto Scaling group to lower costs.

Answer

Increase the instance size to handle peak load.

Question 3

A company wants to reduce costs for its Amazon S3 storage. Which TWO strategies are effective?

Accepted Answer

Use S3 Lifecycle policies to transition objects to S3 Glacier Deep Archive after a period.. S3 Lifecycle policies transition objects to lower-cost storage classes. S3 Object Tagging helps organize data but does not directly reduce costs. S3 Transfer Acceleration increases costs. S3 Replication increases costs. S3 Intelligent-Tiering can be cost-effective for unknown access patterns.

Answer

Enable S3 Object Tagging to categorize data.

Answer

Enable S3 Replication to another region for disaster recovery.

Answer

Enable S3 Transfer Acceleration for faster uploads.

Question 4

An administrator attaches the above IAM policy to a user. The user needs to stop an EC2 instance to save costs. The user reports that they are unable to stop the instance. What is the MOST likely cause?

Accepted Answer

The instance is part of an Auto Scaling group.. The most likely cause is that the instance is part of an Auto Scaling group (ASG). Although the IAM policy allows ec2:StopInstances, stopping an instance that belongs to an ASG will not effectively reduce costs because the ASG will automatically launch a replacement instance to maintain the desired capacity. Additionally, ASG settings such as health checks or scale-in protection may prevent the instance from being stopped directly or cause it to be immediately replaced, making the stop action ineffective for cost savings. Therefore, the user's inability to stop the instance to save costs is due to the instance being managed by an Auto Scaling group.

Answer

The instance has termination protection enabled.

Answer

The IAM policy does not allow ec2:StopInstances.

Answer

The user does not have permission to describe instances.

Question 5

An administrator runs the above CloudWatch command to analyze CPU utilization for an EC2 instance. The instance is currently running with a t3.large instance type. The company wants to optimize costs. Based on the data, which action should the administrator take?

Accepted Answer

Downsize the instance to t3.medium to reduce costs.. The average CPU utilization over the week is low (around 15.5%), indicating the instance is over-provisioned. Downsizing to a t3.medium (half the vCPUs and memory) would likely be sufficient and reduce costs. Reserved Instances would be cost-effective only if the instance runs consistently, but the current utilization is low. Scaling up would increase costs. Stopping the instance is not an option if needed.

Answer

Stop the instance to save costs immediately.

Answer

Scale up the instance to t3.xlarge to improve performance.

Answer

Purchase a Reserved Instance for the current instance type.

Question 6

A company runs a web application on EC2 instances with Elastic Load Balancing. They notice that costs are higher than expected. What is the MOST cost-effective way to optimize costs while maintaining high availability?

Accepted Answer

Use a combination of Reserved Instances for baseline traffic and On-Demand for spikes.. Reserved Instances provide significant discounts for steady-state workloads. On-Demand is more expensive, and Spot Instances may not ensure high availability. Scaling down instances reduces capacity.

Answer

Use Spot Instances for all traffic.

Answer

Use On-Demand instances for all traffic.

Answer

Reduce the number of instances to one.

Question 7

An application runs on EC2 instances behind an ALB. Users report slow response times. CPU utilization averages 90% during peak hours. What is the MOST effective way to improve performance?

Accepted Answer

Increase the instance size to a larger type.. Increasing the instance size (scaling up) provides more CPU resources directly, addressing the high utilization. While Auto Scaling could add more instances, the question specifically asks about the given options, and D is the most effective among them. Detailed monitoring (A) only provides metrics, not performance improvement. Memory-optimized (B) does not help CPU-bound issues. Security group rules (C) do not affect compute performance.

Answer

Enable detailed monitoring on CloudWatch.

Answer

Switch to a memory-optimized instance type.

Answer

Add more Security Group rules.

Question 8

A SysOps administrator wants to monitor the cost of EC2 instances. Which AWS service should be used to visualize and track costs over time?

Accepted Answer

AWS Cost Explorer. AWS Cost Explorer is designed for cost visualization and analysis. CloudWatch is for performance metrics, Trusted Advisor provides recommendations, and Budgets sets alerts.

Answer

AWS CloudWatch

Answer

AWS Budgets

Answer

AWS Trusted Advisor

Question 9

A company uses S3 standard storage for all data. They have data that is accessed rarely but must be retained for 7 years. Which storage class would be MOST cost-effective?

Accepted Answer

S3 Glacier Deep Archive. S3 Glacier Deep Archive is the lowest-cost storage for long-term archival. S3 Standard is expensive, S3 IA is for infrequent access but not long-term, and S3 One Zone IA is less durable.

Answer

S3 One Zone-IA

Answer

S3 Standard

Answer

S3 Intelligent-Tiering

Question 10

A SysOps administrator notices that a Lambda function is timing out after 30 seconds. The function processes large files from S3. How can the administrator improve performance while minimizing cost?

Accepted Answer

Increase the memory allocation of the Lambda function.. Increasing the memory allocation of the Lambda function also proportionally increases the allocated CPU power, which directly reduces the execution time for CPU-bound tasks like processing large files. This often resolves timeout issues without incurring additional cost per invocation, as the cost is a product of memory and duration, and a faster execution can offset the higher memory price.

Answer

Increase the timeout value to 5 minutes.

Answer

Enable Provisioned Concurrency.

Answer

Deploy the function on an EC2 instance.

Question 11

An application uses an RDS MySQL DB instance. The administrator notices that read performance is poor during peak hours. What is a cost-effective way to improve read performance?

Accepted Answer

Create a read replica in the same region.. Creating a read replica offloads read traffic from the primary RDS instance, improving read performance during peak hours at a relatively low cost. Option A (ElastiCache) adds complexity and additional cost. Option B (Multi-AZ) is for high availability and disaster recovery, not for read performance. Option C (scaling up) addresses performance but is more expensive than adding a read replica.

Answer

Use Amazon ElastiCache for caching.

Answer

Enable Multi-AZ deployment.

Answer

Scale up the DB instance to a larger size.

Question 12

A company wants to receive alerts when their monthly AWS spending exceeds $1,000. Which AWS service should be used?

Accepted Answer

AWS Budgets. AWS Budgets allows setting cost thresholds and alerts. CloudWatch alarms are for metrics, not budgets. Cost Explorer is for visualization. Trusted Advisor provides recommendations.

Answer

AWS Trusted Advisor

Answer

AWS CloudWatch

Answer

AWS Cost Explorer

Question 13

A company is running a production web application on EC2 instances. Which TWO actions would improve both cost efficiency and performance?

Accepted Answer

Purchase Reserved Instances for the baseline capacity.. Options B and E are correct. Purchasing Reserved Instances for the baseline capacity reduces cost compared to On-Demand pricing. Implementing Auto Scaling adjusts capacity based on demand, ensuring performance during peaks and cost savings during low traffic. Option A (detailed monitoring) incurs additional cost without direct performance benefit. Option C (terminating idle instances) saves cost but does not improve performance. Option D (larger instance types) may improve performance but typically increases cost, making it not cost-efficient.

Answer

Enable detailed monitoring on all instances.

Answer

Terminate all idle instances.

Answer

Use larger instance types for all instances.

Question 14

An application writes logs to an S3 bucket. The logs are accessed frequently for the first 30 days, then rarely after that, but must be retained for 7 years. Which THREE steps should be taken to optimize cost? (Choose three.)

Accepted Answer

Use an S3 Lifecycle policy to transition objects to S3 Glacier Deep Archive after 90 days.. S3 Glacier Deep Archive is the lowest-cost storage class for long-term archival data, making it ideal for logs that are rarely accessed after 90 days. An S3 Lifecycle policy automates the transition from a higher-cost class (e.g., Standard-IA) to Glacier Deep Archive, reducing storage costs while retaining the data for the required 7-year period.

Answer

Delete logs older than 30 days.

Answer

Use S3 Intelligent-Tiering to automatically optimize costs.

Question 15

Which TWO AWS services can be used to monitor the performance of an EC2 instance?

Accepted Answer

AWS Systems Manager. Amazon CloudWatch is the primary service for monitoring EC2 performance metrics like CPU utilization, network, and disk I/O. AWS Systems Manager can also collect performance data through Inventory and Run Command, providing operational insights. AWS CloudTrail logs API activity for auditing, not performance. AWS Trusted Advisor offers cost and security recommendations. AWS Config tracks configuration changes, not performance metrics.

Answer

AWS CloudTrail

Answer

AWS Trusted Advisor

Answer

AWS Config