SOA-C02 Cost and Performance Optimization Practice Test 6 — 15 Questions

Question 1

A company stores 1 PB of data in Amazon S3 Standard. The data is accessed frequently for the first 30 days, then rarely accessed afterwards. The company needs to optimize storage costs. What should they do?

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

Accepted Answer

Configure an S3 Lifecycle policy to transition objects to S3 Standard-IA after 30 days, then to S3 Glacier Deep Archive after 90 days.. It uses an S3 Lifecycle policy to automatically transition objects to S3 Standard-IA after 30 days (when access drops), then to S3 Glacier Deep Archive after 90 days for long-term cold storage. This balances cost and access needs: Standard-IA offers lower storage cost than Standard for infrequent access, and Glacier Deep Archive provides the lowest cost for rarely accessed data after 90 days. The policy automates the transitions, avoiding manual effort and ensuring cost optimization without data loss.

Answer

Move all objects to S3 Intelligent-Tiering immediately.

Answer

Delete objects older than 30 days using S3 Lifecycle expiration.

Answer

Manually change the storage class of each object to S3 Glacier Deep Archive after 30 days.

Question 2

A company uses Amazon CloudWatch Logs to store application logs. The logs are retained indefinitely. The compliance team requires logs to be retained for 7 years. What is the MOST cost-effective way to meet this requirement?

Accepted Answer

Set a log retention policy in CloudWatch Logs to expire logs after 7 years.. Setting a log retention policy in CloudWatch Logs is the most cost-effective way because it automatically deletes logs older than the specified period (7 years) without incurring additional storage or export costs. Option A is incorrect because CloudWatch Logs retention policy, not exporting to S3, is simpler and cheaper. Option B is incorrect because exporting to S3 incurs data transfer costs and S3 storage costs, and while Glacier Deep Archive is cheap, the lifecycle transition may incur costs and the total cost is higher than simple retention policy. Option C is incorrect because disabling logging after 7 years does not address the retention requirement and may violate compliance. Option D is correct as it directly meets the 7-year retention requirement with minimal cost and management overhead.

Answer

Export logs to Amazon S3 and immediately transition to S3 Glacier Deep Archive.

Answer

Export logs to Amazon S3 and create an S3 Lifecycle policy to transition objects to S3 Glacier Deep Archive after 7 years.

Answer

Disable logging after 7 years to stop incurring costs.

Question 3

A company uses an Application Load Balancer (ALB) to distribute traffic to EC2 instances. The SysOps team wants to reduce costs by ensuring that idle capacity is minimized. Which configuration should they implement?

Accepted Answer

Configure an Auto Scaling group with a target tracking scaling policy based on ALB request count per target.. A target tracking scaling policy dynamically adjusts the number of instances to maintain a target metric (ALB request count per target), which minimizes idle capacity. Option A is wrong because while step scaling can be used, target tracking is more efficient and easier to configure for maintaining optimal utilization. Option C is wrong because increasing instances for peak load leads to over-provisioning and wasted resources during off-peak times. Option D is wrong because setting desired capacity to max expected load results in constant idle capacity when demand is lower.

Answer

Configure an Auto Scaling group with a step scaling policy based on CPU utilization.

Answer

Increase the number of EC2 instances in the Auto Scaling group to handle peak load.

Answer

Set the Auto Scaling group desired capacity to the maximum expected load.

Question 4

A company uses this IAM policy to restrict S3 uploads to the STANDARD storage class only. A developer tries to upload an object to the bucket using the CLI without specifying a storage class. What will happen?

Accepted Answer

The upload will succeed because the default storage class is STANDARD.. The IAM policy condition requires s3:x-amz-storage-class to be STANDARD. When the developer does not specify a storage class in the CLI upload command, the default storage class STANDARD is applied, which matches the condition, so the upload succeeds. Option A is wrong because the condition does allow PutObject when the storage class is STANDARD. Option B is wrong because the bucket default storage class does not affect the IAM policy evaluation; the policy checks the actual storage class of the upload, which defaults to STANDARD. Option D is wrong because the condition does not require explicit specification; it only checks the value, and the default satisfies it.

Answer

The upload will fail because the condition does not allow PutObject.

Answer

The upload will succeed if the bucket has a default storage class of STANDARD-IA.

Answer

The upload will fail because the condition requires explicit specification of the storage class.

Question 5

A company wants to reduce costs for their Amazon RDS for PostgreSQL database. Which TWO actions would help achieve this?

Accepted Answer

Stop the database instance during non-business hours.. Options B and E are correct because stopping the database instance during non-business hours reduces compute costs by eliminating charges when the instance is not used, and purchasing a Reserved Instance for a predictable workload provides a significant discount compared to On-Demand pricing. Option A is incorrect because Multi-AZ deployment increases costs due to standby instance charges. Option C is incorrect because deletion protection does not reduce costs. Option D is incorrect because increasing backup retention to 35 days increases storage costs.

Answer

Enable Multi-AZ deployment for high availability.

Answer

Enable deletion protection to prevent accidental deletion.

Answer

Increase the backup retention period to 35 days.

Question 6

A SysOps administrator is optimizing an AWS Lambda function that processes data from an S3 bucket. The function currently runs with 128 MB memory and a 5-second timeout. The function experiences timeouts for large files. The administrator wants to improve performance and reduce cost. Which TWO actions should they take?

Accepted Answer

Enable provisioned concurrency to reduce cold starts.. To improve performance and reduce cost for a Lambda function that times out on large files, the two best actions are enabling provisioned concurrency (B) to reduce cold starts, and increasing memory (E) to provide more CPU and potentially faster execution, which can reduce execution time and may lower cost due to faster processing. Option A is incorrect because increasing timeout to 15 minutes does not improve performance; it may increase cost if the function runs longer. Option C is incorrect because using S3 Standard-IA is for storage cost optimization, not for compute performance. Option D is incorrect because creating multiple Lambda functions does not address the performance of a single function and may increase complexity.

Answer

Increase the function timeout to 15 minutes.

Answer

Configure the S3 event notification to use S3 Standard-IA for the input files.

Answer

Create multiple Lambda functions to process different files concurrently.

Question 7

A company runs a web application on EC2 instances with an Auto Scaling group. The application uses an Amazon RDS MySQL database. During a traffic spike, the database CPU utilization reaches 90%. The SysOps team needs to improve database performance cost-effectively. Which THREE actions should they take?

Accepted Answer

Enable RDS Performance Insights to identify slow queries.. To cost-effectively improve database performance during traffic spikes, the SysOps team should focus on read scaling and connection management. Option C (RDS Performance Insights) helps identify slow queries and performance bottlenecks, enabling targeted optimization. Option D (RDS Read Replicas) offloads read traffic from the primary instance, reducing CPU load for read-heavy workloads. Option E (RDS Proxy) efficiently manages database connections, reducing overhead on the database instance. Option A (Multi-AZ) is for high availability and failover, not performance improvement. Option B (upgrading instance type) involves vertical scaling, which is more expensive and less flexible than horizontal scaling with Read Replicas.

Answer

Enable Multi-AZ for the RDS instance.

Answer

Upgrade the RDS instance to a larger instance type.

Question 8

A company has three EC2 instances as shown in the exhibit. The company pays for a t3.micro Reserved Instance. Which instance(s) will receive the RI discount?

Accepted Answer

Only i-0abcd1234. RI discounts apply to running instances of the same instance size (or size flexible family). The t3.micro RI covers t3.micro instances; the t3.medium is larger and not covered. The stopped instance does not run, so no discount. Option B is wrong because the stopped instance does not run. Option C is wrong because t3.medium is not covered. Option D is wrong because only the t3.micro running instance qualifies.

Answer

i-0abcd1234 and i-0abcd5678

Answer

i-0abcd1234 and i-0abcd9012

Answer

All three instances

Question 9

A SysOps administrator reviews the CloudWatch metrics for an EC2 instance as shown. The instance is part of an Auto Scaling group with a target tracking scaling policy based on average CPU utilization set to 50%. During the time period shown, what is the expected behavior?

Accepted Answer

The Auto Scaling group will scale out because CPU utilization exceeded 50% for several consecutive data points.. CPU utilization peaks at 95.1% at 00:20, exceeding the 50% target, so the Auto Scaling group should scale out. Option A is wrong because it does exceed the target. Option B is wrong because the average over the hour is around 47%, but the policy reacts to sustained breaches; the peak would trigger scaling. Option D is wrong because scaling would occur.

Answer

The Auto Scaling group will not scale because the average CPU utilization over the hour is below 50%.

Answer

The Auto Scaling group will scale in because the CPU utilization dropped below 50% at the end.

Answer

The Auto Scaling group will not scale because the metric shows a decline after the peak.

Question 10

A company runs a web application on EC2 instances behind an ALB. They want to optimize costs for variable traffic patterns while maintaining high availability. Which solution is MOST cost-effective?

Accepted Answer

Use a mix of On-Demand and Spot Instances in an Auto Scaling group with a target tracking scaling policy.. The most cost-effective because it combines On-Demand Instances for baseline capacity and Spot Instances for burstable traffic, leveraging lower Spot prices while maintaining high availability through Auto Scaling with a target tracking policy. Option A is wrong because Dedicated Hosts are expensive and provide no cost benefit for variable traffic. Option C is wrong because Reserved Instances require a 1- or 3-year commitment and are not suitable for variable traffic; they are better for steady-state workloads. Option D is wrong because using only On-Demand Instances is more expensive than using a mix that includes Spot Instances.

Answer

Use Dedicated Hosts to run the application and share resources across multiple accounts.

Answer

Purchase Reserved Instances for the expected baseline capacity and use On-Demand for spikes.

Answer

Use only On-Demand EC2 Instances with an Auto Scaling group to handle variable traffic.

Question 11

A SysOps administrator receives an AWS Budgets alert that the monthly cost for an S3 bucket has increased by 300% compared to the previous month. The bucket stores log files and uses S3 Standard storage. The bucket has versioning enabled and lifecycle policies that transition objects to S3 Glacier Deep Archive after 90 days. What is the MOST likely cause of the cost increase?

Accepted Answer

The cost of lifecycle transition requests to Glacier Deep Archive.. S3 Lifecycle transition requests cost per object, and the transition to Glacier Deep Archive incurs a cost. Option A is wrong because S3 Standard storage costs are for the first 90 days, not the transition. Option C is wrong because object size is not mentioned as a change. Option D is wrong because data transfer costs are not typically associated with lifecycle transitions.

Answer

The increased storage costs due to S3 Standard storage for the first 90 days.

Answer

Data transfer costs for downloading logs from the bucket.

Answer

The cost of storing multiple versions of objects due to versioning.

Question 12

A company is using AWS CloudFormation to deploy infrastructure. They want to reduce costs by identifying unused resources. Which AWS service should they use to monitor and report on resource utilization and cost?

Accepted Answer

AWS Trusted Advisor. AWS Trusted Advisor provides cost optimization checks, including identifying idle resources and underutilized instances, helping reduce costs. Option B (AWS Config) is incorrect because it tracks configuration changes and compliance, not cost optimization. Option C (Amazon CloudWatch) is incorrect because it monitors metrics and logs, not cost optimization directly. Option D (AWS CloudTrail) is incorrect because it logs API activity, not cost or resource utilization.

Answer

AWS Config

Answer

Amazon CloudWatch

Answer

AWS CloudTrail

Question 13

A company runs a production database on a db.r5.large RDS instance with Multi-AZ enabled. They notice that the CPU utilization is consistently below 10% and memory usage is below 20%. The application is not expected to grow significantly. Which action would optimize costs without sacrificing high availability?

Accepted Answer

Change the instance type to a smaller size, such as db.t3.medium, and keep Multi-AZ.. The instance is over-provisioned; downsizing to a smaller instance type (e.g., db.r5.large to db.t3.medium) reduces cost. Multi-AZ should be retained for high availability. Option A is wrong because removing Multi-AZ sacrifices high availability. Option B is wrong because Reserved Instances require a commitment and may not be cost-effective if the instance type is changed. Option D is wrong because moving to a larger instance increases costs.

Answer

Remove Multi-AZ and use a single-AZ deployment to reduce costs.

Answer

Purchase a Reserved Instance for the current instance type to get a discount.

Answer

Change the instance type to a larger size, such as db.r5.xlarge, to improve performance.

Question 14

A company has a web application that uses an Application Load Balancer (ALB) and an Auto Scaling group of EC2 instances. The Auto Scaling group uses a dynamic scaling policy based on average CPU utilization. The SysOps administrator notices that during traffic spikes, the scaling policy adds instances too slowly, causing performance degradation. Which action should the administrator take to improve performance without significantly increasing costs?

Accepted Answer

Change the scaling policy to a target tracking policy with a target CPU utilization of 70%.. A target tracking policy with a target CPU utilization of 70% will proactively scale out to maintain the target, reacting faster to traffic spikes compared to a simple or step scaling policy. Option A is incorrect because scheduled scaling is not effective for unpredictable spikes. Option B is wrong because increasing the cooldown period would slow down scaling even more. Option C is wrong because a simple scaling policy with a static threshold is less responsive than target tracking. Therefore, switching to target tracking improves responsiveness without significant cost increase.

Answer

Use a scheduled scaling policy to add instances during known peak hours.

Answer

Increase the cooldown period for the scaling policy to allow instances to warm up.

Answer

Switch to a simple scaling policy that scales out when CPU exceeds 80%.

Question 15

A SysOps administrator is reviewing the monthly AWS bill and notices a significant cost for data transfer from EC2 to the internet. The EC2 instances are in a VPC and serve content to users. Which action would MOST effectively reduce data transfer costs?

Accepted Answer

Use Amazon CloudFront as a content delivery network (CDN).. Use Amazon CloudFront as a content delivery network (CDN). CloudFront caches content at edge locations, which reduces the amount of data transferred from the EC2 origin to the internet, lowering data transfer costs. Option A is incorrect because VPC endpoints provide private connectivity to AWS services and do not reduce data transfer costs to the internet. Option C is incorrect because moving to a different AWS Region does not reduce data transfer costs and may introduce higher latency. Option D is incorrect because a NAT Gateway adds additional cost for each gigabyte processed and is not a solution for reducing outbound data transfer costs; it is used for internet access from private subnets.

Answer

Use VPC endpoints to connect to S3 and DynamoDB.

Answer

Move the EC2 instances to a different AWS Region with lower data transfer rates.

Answer

Use a NAT Gateway to route traffic through a single IP.