SOA-C02 Cost and Performance Optimization Practice Test 7 — 15 Questions

Question 1

A company has an S3 bucket that stores millions of small objects (1-10 KB) and uses S3 Standard storage. The bucket receives frequent PUT requests and occasional GET requests. The monthly bill shows high costs for S3 PUT requests. Which action would reduce costs?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Aggregate small objects into larger files (e.g., 1 MB) before uploading to S3.. Aggregating small objects into larger files reduces the number of PUT requests, which are billed per request. This directly addresses the high PUT request costs. Option A is wrong because S3 Glacier Deep Archive is for archival storage and does not reduce PUT request costs; in fact, PUT requests to Glacier are more expensive. Option C is wrong because S3 Intelligent-Tiering optimizes storage costs by moving data between tiers based on access patterns, but it does not reduce PUT request costs. Option D is wrong because lifecycle policies transition objects after upload and do not reduce the cost of the initial PUT requests.

Answer

Move the objects to S3 Glacier Deep Archive to reduce storage cost.

Answer

Move the objects to S3 Intelligent-Tiering to optimize storage costs.

Answer

Use S3 Lifecycle policies to transition objects to S3 Standard-IA after 30 days.

Question 2

A SysOps administrator wants to monitor the cost and usage of AWS resources for different departments. Which AWS service should they use to tag resources and generate cost allocation reports?

Accepted Answer

AWS Cost Explorer with cost allocation tags. AWS Cost Explorer with cost allocation tags allows filtering and grouping of costs by tags (e.g., department), enabling cost allocation reporting. Option A (AWS Trusted Advisor) provides optimization recommendations, not cost reports. Option B (AWS Budgets) sets cost alerts but does not generate detailed cost allocation reports. Option C (AWS Config) tracks resource configuration changes, not costs.

Answer

AWS Trusted Advisor

Answer

AWS Budgets

Answer

AWS Config

Question 3

A company is using Amazon RDS for MySQL with Multi-AZ deployment. They want to optimize costs while maintaining high availability. Which TWO actions should the SysOps administrator take?

Accepted Answer

Purchase Reserved Instances for the database instance.. Purchasing Reserved Instances for a Multi-AZ RDS instance provides significant discounts over On-Demand pricing, reducing costs while maintaining high availability. Option D is correct because reviewing and downsizing the instance size if it is over-provisioned directly reduces costs without impacting availability. Option B is incorrect because removing Multi-AZ would eliminate high availability. Option C is incorrect because RDS does not support auto scaling for compute capacity; you can use read replicas or adjust instance size manually. Option E is incorrect because moving to a single-AZ deployment sacrifices high availability, which conflicts with the requirement.

Answer

Remove Multi-AZ to reduce costs.

Answer

Enable auto scaling for the RDS instance to handle variable load.

Answer

Move to a single-AZ deployment and take snapshots for recovery.

Question 4

A company runs a critical web application on EC2 instances behind an ALB. The application experiences unpredictable traffic spikes. The SysOps administrator wants to ensure that the application can handle spikes without performance degradation while minimizing costs. Which TWO actions should the administrator take?

Accepted Answer

Use a mix of On-Demand and Spot Instances in the Auto Scaling group.. Spot Instances can reduce costs if the application can handle interruptions. Option D is correct because target tracking scaling adjusts capacity based on load. Option B is wrong because DynamoDB auto scaling is not relevant for EC2. Option C is wrong because scheduled scaling cannot handle unpredictable spikes. Option E is wrong because increasing instance size may not be as cost-effective as scaling out.

Answer

Use Amazon DynamoDB auto scaling to handle the spikes.

Answer

Use scheduled scaling to add instances during expected peak hours.

Answer

Use larger EC2 instance types to handle spikes.

Question 5

A company is using Amazon S3 to store data for analytics. The data is accessed frequently for the first 30 days, then rarely after that. The company wants to optimize storage costs. Which THREE actions should the SysOps administrator recommend?

Accepted Answer

Use S3 Intelligent-Tiering to automatically optimize storage costs.. The correct actions are A, C, D. Option A: S3 Intelligent-Tiering automatically moves data between tiers based on access patterns, optimizing costs for data with changing access patterns. Option C: A lifecycle policy to transition objects to S3 Glacier Deep Archive after 90 days is appropriate for data that is rarely accessed after the initial 30 days. Option D: A lifecycle policy to transition objects to S3 Standard-IA after 30 days is a good cost-saving measure for data that is accessed infrequently after the first 30 days. Option B is incorrect because S3 One Zone-IA is not durable enough for analytics data that may need availability, and it does not automatically optimize costs like Intelligent-Tiering. Option E is incorrect because using S3 Standard for all data would be more expensive than using the lifecycle policies or Intelligent-Tiering.

Answer

Use S3 One Zone-IA for all data after 30 days to reduce costs.

Answer

Use S3 Standard storage for all data to ensure high performance.

Question 6

A company is using Amazon CloudFront to deliver content to users worldwide. They notice high data transfer costs. Which THREE actions can reduce CloudFront data transfer costs?

Accepted Answer

Use a CloudFront price class that only uses the cheapest edge locations.. Using a lower price class restricts CloudFront to the cheapest edge locations, reducing data transfer costs. Option C is correct because enabling compression reduces the amount of data transferred to users, lowering costs. Option E is correct because CloudFront Origin Shield adds an additional caching layer that reduces origin requests, decreasing data transfer from origin to edge. Option A is incorrect because Lambda@Edge incurs additional compute charges, not reducing costs. Option D is incorrect because adding more edge locations does not inherently reduce costs; it may increase coverage but does not guarantee lower transfer fees.

Answer

Use Lambda@Edge to customize content.

Answer

Add more edge locations to improve cache hit ratio.

Question 7

A company runs a web application on EC2 instances in an Auto Scaling group behind an ALB. The application experiences variable traffic, with peak usage during business hours and low traffic at night. The SysOps administrator wants to reduce costs while maintaining performance. The current setup uses On-Demand instances only. The application is stateful and stores session data in an ElastiCache Redis cluster. The administrator has identified that the application can handle Spot Instance interruptions gracefully by redirecting users to a fallback page. The company has a budget of $10,000 per month for EC2 instances, and current costs are $8,000 per month. The administrator wants to reduce costs further without compromising availability for most users. Which solution is MOST cost-effective?

Accepted Answer

Use a mixed instances policy with Spot Instances during off-peak hours and On-Demand during peak hours, using Auto Scaling scheduled scaling.. The most cost-effective because it leverages Spot Instances during off-peak hours (low traffic) to reduce costs significantly while maintaining On-Demand instances during peak hours to ensure performance and availability. Auto Scaling scheduled scaling aligns with the predictable traffic pattern. Option A is less cost-effective because a large On-Demand base capacity would increase costs unnecessarily; Spot can be used more aggressively during off-peak. Option B is not ideal because Reserved Instances require upfront commitment and are best for steady-state workloads, not variable traffic. Option C would risk excessive Spot interruptions during peak hours, degrading user experience despite the fallback page.

Answer

Increase the On-Demand base capacity to handle peak load and use Spot for any additional capacity.

Answer

Purchase Reserved Instances for the minimum expected capacity and use On-Demand for the rest.

Answer

Use only Spot Instances at all times to maximize savings, and rely on the fallback page for interruptions.

Question 8

A company runs a data processing pipeline on AWS. The pipeline consists of EC2 instances that process data from an S3 bucket and write results to another S3 bucket. The processing job runs every hour and takes approximately 45 minutes. The current setup uses On-Demand instances. The SysOps administrator wants to reduce costs because the monthly EC2 bill is $5,000. The application is fault-tolerant and can handle interruptions by reprocessing data from the last checkpoint. The administrator has tested Spot Instances and found that they are interrupted about 10% of the time. The company has a strict requirement that the job must complete within 60 minutes every hour. Which solution would reduce costs while ensuring the job completes on time?

Accepted Answer

Use a Spot Fleet with a fallback to On-Demand if Spot capacity is not available.. A Spot Fleet with a fallback to On-Demand ensures the job completes within the 60-minute window even if Spot Instances are interrupted, while reducing costs by using cheaper Spot Instances when available. Option A is wrong because Reserved Instances require a 1- or 3-year commitment and may not be cost-effective for a job that runs only 45 minutes per hour, leading to wasted capacity. Option B is wrong because using a single larger On-Demand instance would increase costs, not reduce them. Option D is wrong because using Spot Instances only, even with more instances, risks exceeding the 60-minute deadline due to the 10% interruption rate; the fallback to On-Demand is necessary to guarantee completion time.

Answer

Purchase Reserved Instances for the expected capacity to get a discount.

Answer

Use a single larger On-Demand instance to complete the job faster.

Answer

Use Spot Instances only and increase the number of instances to compensate for interruptions.

Question 9

A company is running a production web application on EC2 instances behind an Application Load Balancer. The company wants to optimize costs without sacrificing performance. Which TWO actions should the SysOps administrator take?

Accepted Answer

Purchase Reserved Instances for the baseline capacity.. (Reserved Instances) provides a significant discount for steady-state workloads, and Option C (Auto Scaling) ensures capacity matches demand, preventing over-provisioning. Option B (Dedicated Hosts) is more expensive and unnecessary. Option D (T3 unlimited) could cause unexpected costs if credits exhausted. Option E (Multiple instance types per AZ) is not a cost optimization.

Answer

Use Dedicated Hosts for all instances to control placement.

Answer

Enable T2/T3 unlimited to handle spikes without throttling.

Answer

Use multiple instance types in each Availability Zone.

Question 10

A SysOps administrator manages a fleet of 50 EC2 instances running a batch processing application. The instances are launched via an Auto Scaling group with a dynamic scaling policy based on CPU utilization. The company recently switched to a new workload that is memory-intensive, causing frequent scale-out events. The administrator notices that the CPU utilization remains below 40%, but memory usage is consistently above 80%. The scaling policy does not trigger appropriately, leading to performance degradation. The administrator must optimize the solution to respond to memory pressure without incurring unnecessary costs. Which action should the administrator take?

Accepted Answer

Create a custom CloudWatch metric for memory utilization and configure a target tracking scaling policy using that metric.. It directly addresses the memory bottleneck by creating a custom CloudWatch metric for memory utilization and using a target tracking scaling policy. This allows the Auto Scaling group to automatically adjust capacity based on actual memory pressure, which is the real performance issue. Option B (manual scaling) is not automated and may lead to over-provisioning or under-provisioning. Option C (step scaling with CPU) does not solve the memory problem, and a wider cooldown would only delay scaling. Option D (changing instance type) is a reactive measure that does not provide dynamic scaling and may increase costs without eliminating the need for scaling policies.

Answer

Increase the minimum size of the Auto Scaling group to 10 instances and use manual scaling for peak times.

Answer

Change the dynamic scaling policy to a step scaling policy based on CPU utilization with a wider cooldown period.

Answer

Replace the current instance type with a memory-optimized instance type such as r5.large.

Question 11

A company runs a fleet of EC2 instances in a production environment. The instances are part of an Auto Scaling group that uses a launch template with a m5.large instance type. The company's SysOps administrator notices that the instances are often over-provisioned, with average CPU utilization below 20% for the past month. The administrator wants to reduce costs without affecting application performance. The application is stateless and can handle temporary performance degradation. Which action should the administrator take?

Accepted Answer

Modify the launch template to use a t3.medium instance type.. Switching to a smaller instance type (t3.medium) reduces cost while still providing burstable performance for occasional spikes. Option A (increase minimum) would increase cost. Option C (purchase Reserved Instances for current size) locks in over-provisioned capacity. Option D (enable detailed monitoring) increases CloudWatch costs without addressing instance size.

Answer

Purchase Reserved Instances for the current m5.large instances to lower hourly cost.

Answer

Enable detailed monitoring on all instances to collect more data.

Answer

Increase the minimum size of the Auto Scaling group to reduce scale-out events.

Question 12

A SysOps administrator is responsible for an AWS account that hosts a development environment. The environment includes several EC2 instances that are used only during business hours (9 AM to 5 PM) on weekdays. The administrator wants to reduce costs by stopping the instances during off-hours. Which action should the administrator take to automate this process?

Accepted Answer

Use the AWS Instance Scheduler to define a schedule that stops instances at 5 PM and starts them at 9 AM on weekdays.. AWS Instance Scheduler is a solution that automatically starts and stops EC2 instances on a defined schedule, ideal for reducing costs during off-hours. Option A is manual, not automated. Option B: Auto Scaling with scheduled scaling sets desired capacity to 0, but it terminates instances rather than stopping them, and the instances would be recreated when scaled up, not resumed. Option C: A CloudWatch alarm based on low CPU utilization could stop instances, but it is not a fixed schedule and may not align with business hours, leading to premature stops or missed stops.

Answer

Manually stop the instances at 5 PM and start them at 9 AM each weekday.

Answer

Create an Auto Scaling group with a scheduled scaling action to set desired capacity to 0 during off-hours.

Answer

Set up a CloudWatch alarm that stops instances when CPU utilization is below 1% for 30 minutes.

Question 13

A company runs a web application on EC2 instances behind an Application Load Balancer (ALB). The application experiences variable traffic with occasional spikes. The SysOps administrator wants to optimize costs while ensuring that the application can handle spikes without performance degradation. The current setup uses a fixed number of instances. Which action should the administrator take?

Accepted Answer

Implement an Auto Scaling group with a target tracking scaling policy based on ALB request count per target.. Implementing an Auto Scaling group with a target tracking scaling policy based on ALB request count per target automatically adjusts the number of EC2 instances to match traffic patterns. During spikes, it adds instances to handle the load without performance degradation, and during low traffic, it reduces instances to optimize costs. Option A (Reserved Instances) lowers hourly cost but locks in a fixed capacity, which cannot handle variable traffic efficiently. Option C (Spot Instances) can be interrupted, risking performance degradation during spikes. Option D (increasing instance size) may handle spikes but is expensive and does not dynamically scale down.

Answer

Purchase Reserved Instances for the current number of instances to reduce hourly cost.

Answer

Replace on-demand instances with Spot Instances for all traffic.

Answer

Increase the instance size to a compute-optimized type to handle spikes.

Question 14

A company runs a web application on EC2 instances behind an Application Load Balancer. The application experiences variable traffic patterns. The operations team notices that during low traffic periods, there are still a large number of running instances, leading to higher costs. What should the team do to reduce costs while maintaining performance?

Accepted Answer

Implement a target tracking scaling policy based on average CPU utilization.. Implementing a target tracking scaling policy based on average CPU utilization allows the Auto Scaling group to automatically scale the number of EC2 instances in response to demand. This ensures that during low traffic periods, the group reduces instance count to minimize costs, while during high traffic it adds instances to maintain performance. Option A is incorrect because using larger instance types would not reduce the number of running instances during low traffic and could increase costs. Option C is incorrect because manual scaling is not automated and may not respond quickly to traffic changes. Option D is incorrect because Reserved Instances provide a discount but do not address the issue of over-provisioning during low traffic; they lock in capacity that may still be unused.

Answer

Replace the existing instances with larger instance types to handle peak load.

Answer

Manually scale down the number of instances during off-peak hours.

Answer

Purchase Reserved Instances for the baseline capacity.

Question 15

A company uses a centralized logging solution with Amazon OpenSearch Service. The log volume has grown significantly, increasing costs. The logs are retained for 90 days for compliance, but only the last 30 days are frequently accessed. Which combination of actions would reduce costs without compromising compliance?

Accepted Answer

Migrate indices older than 30 days to UltraWarm nodes.. Migrating indices older than 30 days to UltraWarm nodes reduces storage costs because UltraWarm provides cost-effective storage for infrequently accessed data. This retains data for the full 90-day compliance period while keeping the last 30 days in hot storage for fast access. Option A is incorrect because moving logs to S3 Glacier would make querying impractical and is not designed for OpenSearch. Option B is incorrect because increasing data nodes would increase costs without addressing storage optimization. Option D is incorrect because deleting indices after 30 days would violate the 90-day retention requirement.

Answer

Move the logs to Amazon S3 Glacier and use a Lambda function to query them.

Answer

Increase the number of data nodes to improve indexing performance.

Answer

Configure an index lifecycle policy to delete indices older than 30 days.