SOA-C02 Cost and Performance Optimization Practice Test 13 — 15 Questions

Question 1

A company runs a web application on a fleet of Amazon EC2 instances behind an Application Load Balancer. The application has predictable traffic patterns with high traffic during business hours and low traffic at night. The SysOps administrator wants to reduce compute costs while ensuring the application remains responsive during peak hours. The administrator has already implemented Auto Scaling based on CPU utilization. Which additional action should the administrator take to optimize costs?

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

Accepted Answer

Purchase Reserved Instances for the baseline capacity and use Spot Instances for the additional capacity during peak hours. It combines Reserved Instances for predictable baseline capacity (lower cost per hour) with Spot Instances for elastic peak demand, leveraging Auto Scaling to handle variable traffic. This hybrid approach reduces compute costs compared to using On-Demand instances for all capacity, while maintaining responsiveness during peak hours.

Answer

Use On-Demand instances only

Answer

Increase the minimum number of instances in the Auto Scaling group

Answer

Use Dedicated Hosts to reduce licensing costs

Question 2

An application runs on c5.xlarge EC2 instances 24 hours a day, 7 days a week in us-east-1. The workload is stable and will not change instance type for at least 12 months. The team wants to reduce compute costs by 30 to 40 percent compared to On-Demand pricing. Which purchasing option achieves this with the lowest financial risk?

Accepted Answer

Purchase a 1-year Standard Reserved Instance for c5.xlarge in us-east-1 with All Upfront or Partial Upfront payment. A 1-year Standard Reserved Instance (RI) with All Upfront or Partial Upfront payment offers a 30-40% discount over On-Demand pricing for a stable, always-on workload. This option provides the lowest financial risk because it commits to a fixed instance type and region for only one year, matching the workload's stable nature without the flexibility premium of Convertible RIs or the interruption risk of Spot Instances.

Answer

Use Spot Instances with an interruption tolerance of 5 minutes for the workload

Answer

Enable EC2 Auto Scaling with a target tracking policy to scale down to zero instances during off-peak hours

Answer

Purchase a 3-year Convertible Reserved Instance to maximize the discount percentage

Question 3

A media company stores millions of video files in S3. Some files are accessed heavily after upload (when new) and rarely afterward; others are accessed unpredictably across months. The team cannot predict which files will be accessed and when. They want to minimize storage costs without risking retrieval latency penalties or per-object retrieval fees. Which storage class is appropriate?

Accepted Answer

Use S3 Intelligent-Tiering so objects automatically move between Frequent and Infrequent Access tiers based on access patterns, with no retrieval fees. S3 Intelligent-Tiering is the correct choice because it automatically moves objects between Frequent Access and Infrequent Access tiers based on changing access patterns, with no retrieval fees and no performance impact (millisecond latency). This matches the unpredictable access pattern described, as the service monitors access at the object level and adjusts storage tier without manual lifecycle rules or retrieval costs.

Answer

Use S3 Standard-IA and configure a lifecycle policy to move objects back to Standard after every access

Answer

Use S3 Glacier Instant Retrieval for all objects because it offers the lowest storage cost with millisecond retrieval

Answer

Use S3 Standard for all objects because it has no retrieval fees and provides the best availability

Question 4

The finance team was surprised by a $12,000 spike in EC2 costs last month caused by a runaway Auto Scaling group. They want to receive an email alert within hours whenever any AWS service cost behaves unexpectedly, without manually setting fixed dollar thresholds for each service. Which AWS cost management feature provides this?

Accepted Answer

Enable Cost Anomaly Detection with an AWS services monitor and create an alert subscription to email the finance team when an anomaly is detected. Cost Anomaly Detection uses machine learning to model historical spending patterns for each AWS service and automatically detects unusual spikes without requiring manual thresholds. By creating an AWS services monitor and linking an alert subscription, the finance team receives email notifications within hours when any service deviates from its expected cost behavior, directly addressing the need for service-agnostic, threshold-free alerts.

Answer

Create an AWS Budget with a monthly EC2 cost threshold of $10,000 and an alert at 80 percent of the threshold

Answer

Enable AWS Cost Explorer and review the daily cost breakdown each morning to spot unexpected charges

Answer

Configure CloudWatch Billing alarms with a static threshold for each AWS service individually

Question 5

Drag and drop the steps to configure a VPC peering connection between two VPCs into the correct order.

Accepted Answer

Step 1: Create the peering request, Step 2: Accept the peering request, Step 3: Update route tables in both VPCs, Step 4: Adjust security groups.. First create the peering request, then accept it, then update route tables in both VPCs, and finally adjust security groups.

Answer

Step 1: Create the peering request, Step 2: Update route tables in both VPCs, Step 3: Accept the peering request, Step 4: Adjust security groups.

Answer

Step 1: Accept the peering request, Step 2: Create the peering request, Step 3: Update route tables in both VPCs, Step 4: Adjust security groups.

Answer

Step 1: Update route tables in both VPCs, Step 2: Create the peering request, Step 3: Accept the peering request, Step 4: Adjust security groups.

Question 6

A company is using Amazon S3 to store historical data. The data is accessed frequently for the first 30 days, then accessed infrequently for the next 90 days, and after 120 days it is rarely accessed but must be retained for 7 years for compliance. Which S3 lifecycle policy provides the LOWEST cost while meeting these requirements?

Accepted Answer

Standard for 30 days, then transition to Standard-IA for 90 days, then to Glacier Deep Archive.. It aligns the storage class transitions precisely with the access patterns: Standard for frequent access (first 30 days), Standard-IA for infrequent access (next 90 days), and Glacier Deep Archive for long-term retention (after 120 days). This minimizes cost by avoiding paying for premium storage when data is rarely accessed, while still meeting the 7-year compliance requirement at the lowest possible storage cost.

Answer

Standard for 30 days, then transition to One Zone-IA for 90 days, then to Glacier Deep Archive.

Answer

Standard for 120 days, then transition to Glacier Deep Archive.

Answer

Standard for 30 days, then transition to Glacier for the remaining life.

Question 7

A company uses Amazon S3 for static website hosting. The website serves thousands of users globally, and the company wants to reduce latency and lower data transfer costs. Which solution should the SysOps administrator implement?

Accepted Answer

Set up Amazon CloudFront as a content delivery network (CDN) in front of the S3 bucket.. Amazon CloudFront is a global content delivery network (CDN) that caches static content at edge locations closer to users, reducing latency and lowering data transfer costs by minimizing direct requests to the S3 origin. By serving cached objects from edge locations, CloudFront also reduces the amount of data transferred from S3, which can significantly decrease S3 data transfer egress charges.

Answer

Use S3 Intelligent-Tiering storage class.

Answer

Enable cross-region replication and serve from multiple buckets.

Answer

Enable S3 Transfer Acceleration on the bucket.

Question 8

A company wants to receive alerts when its AWS costs exceed a certain threshold. Which AWS service should be used?

Accepted Answer

AWS Budgets. AWS Budgets allows you to set custom cost and usage budgets and receive alerts when actual or forecasted costs exceed a defined threshold. It directly supports cost-based alerting with actions such as sending an SNS notification or applying an IAM policy to restrict resources when the budget limit is breached.

Answer

Amazon CloudWatch

Answer

AWS Cost Explorer

Answer

AWS Trusted Advisor

Question 9

A SysOps administrator notices that the monthly bill for Amazon S3 has increased significantly. The company uses S3 for storing application logs and user uploads. The logs are accessed rarely but must be retained for 3 years. User uploads are accessed frequently for the first 30 days, then rarely after. Which S3 lifecycle policy will optimize storage costs?

Accepted Answer

Transition logs to S3 Glacier Deep Archive after 30 days, and transition user uploads to S3 Standard-IA after 30 days, then to Glacier Deep Archive after 90 days.. This lifecycle policy optimizes costs by transitioning logs (rarely accessed but need retention) directly to S3 Glacier Deep Archive after 30 days, and for user uploads (frequently accessed for the first 30 days, then rarely), transition to S3 Standard-IA after 30 days, then to Glacier Deep Archive after 90 days. Option B is wrong because it transitions user uploads (initially frequent access) to Glacier Deep Archive too early, causing retrieval costs. Option C is wrong because logs should be archived, but deleting user uploads after 1 year may be premature. Option D is wrong because it transitions logs to Standard-IA, which is not cost-effective for long-term retention, and user uploads to One Zone-IA, which lacks durability.

Answer

Transition user uploads to S3 Glacier Deep Archive after 30 days, and transition logs to S3 Glacier after 90 days.

Answer

Move logs to S3 Glacier Deep Archive after 30 days, and delete user uploads after 1 year.

Answer

Transition logs to S3 Standard-IA after 30 days, and transition user uploads to S3 One Zone-IA after 30 days.

Question 10

A SysOps administrator needs to reduce data transfer costs for a web application hosted on EC2 instances in a VPC. The application serves content to users over the internet. Which TWO actions will help reduce data transfer costs? (Choose TWO.)

Accepted Answer

Use a VPC Gateway Endpoint for Amazon S3 to keep S3 traffic within AWS.. The correct answers are B and C. Using a VPC Gateway Endpoint for Amazon S3 allows instances to access S3 over the AWS network without traversing the internet, reducing data transfer costs. Amazon CloudFront caches content at edge locations worldwide, so users receive content from edge locations instead of the EC2 origin, reducing data transfer from EC2 to the internet. Option A is incorrect because migrating to private subnets and using AWS Direct Connect does not serve users over the internet; Direct Connect is a dedicated network connection that does not reduce data transfer costs for internet users. Option D is incorrect because an Application Load Balancer distributes traffic but does not inherently reduce data transfer costs; it may even add cost. Option E is incorrect because a larger NAT Gateway increases cost and does not reduce data transfer costs for outbound traffic.

Answer

Move all instances to private subnets and use AWS Direct Connect for user access.

Answer

Use an Application Load Balancer to distribute traffic.

Answer

Use a larger NAT Gateway to improve throughput.

Question 11

A SysOps administrator is investigating a cost increase in a production AWS account. They notice that an EC2 instance with a Reservation has been running continuously for months. The instance type is m5.large in us-east-1. The administrator sees that the instance is using a Standard Reserved Instance (RI) that was purchased 6 months ago for a 1-year term. However, the current utilization shows that the instance is only used for 4 hours per day. What should the administrator do to optimize costs without affecting availability?

Accepted Answer

Modify the existing RI to a smaller instance size (e.g., m5.large to m5.xlarge? no, smaller: e.g., t3.medium) and use Auto Scaling with a schedule to start/stop the instance during business hours.. By modifying the existing Standard RI to a smaller instance size (e.g., within the same family or by converting to a Convertible RI to allow family changes), the administrator can better match the actual low utilization pattern. Additionally, using Auto Scaling with a scheduled scaling policy to start and stop the instance during business hours ensures availability during needed times and reduces waste. Option A is incorrect because stopping the instance does not stop the RI charges; Reserved Instance benefits are applied only to running instances, so the RI would be wasted during off-hours. Option B is incorrect because selling the RI on the Reserved Instance Marketplace typically incurs a loss of the upfront payment and does not directly address the over-provisioning issue. Option D is incorrect because converting to a larger instance family would increase compute capacity per hour, leading to higher costs and even more waste given the low utilization.

Answer

Stop the instance during off-hours using Instance Scheduler, but keep the RI as-is.

Answer

Sell the current RI on the Reserved Instance Marketplace and purchase a new Convertible RI for a smaller instance type.

Answer

Convert the RI to a Convertible RI and exchange it for a larger instance family to get more compute per hour.

Question 12

A company has an S3 bucket policy as shown. A developer tries to upload an object using the AWS CLI without the --no-verify-ssl flag. What will happen?

Accepted Answer

The upload will succeed because the CLI uses HTTPS by default.. The bucket policy denies requests that do not use secure transport (HTTP) but allows HTTPS requests. The AWS CLI uses HTTPS by default, and since the developer did not use --no-verify-ssl, the request is made over HTTPS. Therefore, the upload succeeds. Option D is correct. Option A is incorrect because the CLI uses HTTPS, not HTTP. Option B is incorrect because the policy does not deny all s3:* actions; it only denies requests over HTTP. Option C is incorrect because the policy requires HTTPS, and the CLI complies, so the upload does not fail.

Answer

The upload will succeed only if the developer uses HTTP.

Answer

The upload will fail because the policy denies all s3:* actions.

Answer

The upload will fail because the policy requires explicit HTTPS.

Question 13

A company runs a batch processing job every night that takes 2 hours on a single m5.xlarge EC2 instance. The job is fault-tolerant and can be interrupted. The SysOps administrator wants to reduce costs. Which solution is MOST cost-effective?

Accepted Answer

Use a Spot Instance with a Spot Fleet that includes a fallback to On-Demand if Spot is not available.. The most cost-effective solution is to use a Spot Instance with a Spot Fleet that includes a fallback to On-Demand if Spot is not available (Option B). The job is fault-tolerant and can be interrupted, making it ideal for Spot Instances which offer significant cost savings (up to 90% compared to On-Demand). The Spot Fleet with an On-Demand fallback ensures the job completes even if Spot capacity is unavailable. Option A (On-Demand with CloudWatch alarm) does not reduce costs since On-Demand is more expensive. Option C (Dedicated Host) is costly and unnecessary for a batch job. Option D (Reserved Instance) requires a 1- or 3-year commitment and is not cost-effective for a 2-hour daily job.

Answer

Use an On-Demand instance and set up a CloudWatch alarm to stop it when the job completes.

Answer

Use a Dedicated Host to run the job.

Answer

Purchase a Reserved Instance for the m5.xlarge instance.

Question 14

A SysOps administrator notices that an S3 bucket's storage costs have increased significantly. The bucket stores log files and is configured with S3 Standard storage class. Most logs are accessed only once after 30 days. Which action will reduce costs without affecting data retrieval?

Accepted Answer

Create a lifecycle policy to transition objects to S3 Glacier Instant Retrieval after 30 days.. Transitioning to S3 Glacier Instant Retrieval after 30 days reduces storage cost while maintaining millisecond access. Option A is wrong because S3 Standard-IA has retrieval fees that might increase cost for single access. Option B is wrong because S3 Glacier Deep Archive has long retrieval times (hours), making it unsuitable for logs that may need to be accessed occasionally. Option D is wrong because S3 One Zone-IA is less durable (does not replicate across AZs) and may not be appropriate for log data.

Answer

Create a lifecycle policy to transition objects to S3 Standard-IA after 30 days.

Answer

Create a lifecycle policy to transition objects to S3 Glacier Deep Archive after 30 days.

Answer

Create a lifecycle policy to transition objects to S3 One Zone-IA after 30 days.

Question 15

An administrator runs the above command to list EC2 instances. The company wants to optimize costs. Which instance should the administrator consider terminating first?

Accepted Answer

i-0mnop3456 (t3.medium, stopped in us-east-1c). The instance i-0mnop3456 is stopped but still incurs costs for EBS volumes and possibly Elastic IPs. Terminating it will eliminate those costs. The running instances are in use and may be necessary. The t3.medium instances are smaller and may be needed.

Answer

i-0efgh5678 (t3.large, running in us-east-1b)

Answer

i-0abcd1234 (t3.medium, running in us-east-1a)

Answer

i-0ijkl9012 (t3.xlarge, running in us-east-1a)