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

Question 1

A company uses Amazon S3 to store backups and logs. The total data volume is 50 TB and grows by 2 TB per month. The company requires that data be retained for 7 years. Which THREE actions will optimize storage costs? (Choose THREE.)

Accepted Answer

Use S3 Lifecycle policies to transition data to S3 Glacier Deep Archive after 30 days.. The correct answers are A, C, and D. S3 Lifecycle policies automatically transition objects to cheaper storage classes. S3 Glacier Deep Archive is the lowest-cost storage for long-term retention. S3 Intelligent-Tiering automatically moves data between tiers based on access patterns. Option B is wrong because S3 Standard is expensive for long-term retention. Option E is wrong because requiring retrieval in minutes is not cost-effective for archival data.

Answer

Store all data in S3 Standard for the first year, then delete.

Answer

Use S3 Glacier Flexible Retrieval to allow data retrieval in minutes.

Question 2

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 A and B. Amazon CloudFront caches content at edge locations, reducing data transfer from origin to users. Using a VPC Gateway Endpoint for S3 keeps S3 traffic within AWS, avoiding internet data transfer costs. Option C is wrong because using a larger NAT Gateway increases costs. Option D is wrong because moving to a private subnet and using Direct Connect adds cost. Option E is wrong because using an ALB does not reduce data transfer costs.

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 3

A SysOps administrator reviews the CloudWatch metric data for an EC2 instance. The instance runs a web application that experiences high traffic between 12:00 and 14:00 UTC daily. The administrator wants to optimize costs while maintaining performance. What should the administrator do?

Accepted Answer

Create an Auto Scaling group with a scheduled scaling policy to add instances during peak hours.. The correct answer is C. The instance has low CPU utilization most of the day but spikes to 90% during peak hours. Using a scheduled Auto Scaling to add instances during peak hours ensures performance without over-provisioning. Option A is wrong because the instance is not constantly at high utilization. Option B is wrong because upgrading instance size increases cost during off-peak hours. Option D is wrong because a larger instance would be underutilized.

Answer

Convert the instance to a Reserved Instance to reduce hourly cost.

Answer

Replace the instance with a larger instance type and enable detailed monitoring.

Answer

Increase the instance size to handle peak load at all times.

Question 4

A SysOps administrator attached the IAM policy shown to a user. The user needs to launch EC2 instances for a cost-sensitive project. What is the impact of this policy on cost optimization?

Accepted Answer

The policy allows launching any number of t3.micro instances, potentially increasing costs if many instances are launched.. The correct answer is B. The policy allows running instances only of type t3.micro, which is a low-cost instance. However, it does not restrict the number of instances, so a user could launch many instances, increasing costs. Option A is wrong because the policy restricts instance type. Option C is wrong because t3.micro is a small instance, not a large one. Option D is wrong because the policy does allow running instances with a condition.

Answer

The policy is too restrictive because it only allows t3.micro instances, which may not be sufficient for production workloads.

Answer

The policy does not allow launching any instances because the condition is on RunInstances.

Answer

The policy ensures cost control by allowing only t3.micro instances, which are the cheapest.

Question 5

A SysOps administrator reviews the Lambda invocation metrics for a function. The function processes data from an S3 bucket and is triggered by S3 events. The cost for this function is higher than expected. What should the administrator do to reduce costs?

Accepted Answer

Increase the function's memory allocation to reduce execution time.. The correct answer is B. The function has very high invocations during peak hours (12:00-14:00). Increasing memory reduces execution time, which can lower total cost because Lambda pricing is based on compute time. Option A is wrong because reducing memory increases duration and may increase cost. Option C is wrong because the function is already triggered by events; changing to scheduled invocation may not meet requirements. Option D is wrong because concurrency limit does not reduce total invocations.

Answer

Set a reserved concurrency limit to cap the number of concurrent executions.

Answer

Change the function to be invoked on a schedule instead of by S3 events.

Answer

Reduce the function's memory allocation to lower cost per invocation.

Question 6

A company runs a web application on EC2 instances behind an Application Load Balancer. The application experiences variable traffic patterns. What is the MOST cost-effective way to ensure the application scales based on demand?

Accepted Answer

Use EC2 Auto Scaling with a target tracking scaling policy based on average CPU utilization.. Option C is correct because a target tracking scaling policy automatically adjusts capacity based on a CloudWatch metric, which is cost-effective compared to manual or scheduled scaling. Option A is wrong because manual scaling is not automated. Option B is wrong because scheduled scaling does not handle variable traffic well. Option D is wrong because it over-provisions instances.

Answer

Provision a fixed number of EC2 instances that can handle peak load at all times.

Answer

Use EC2 Auto Scaling with a scheduled scaling policy that adds instances during business hours.

Answer

Use EC2 Auto Scaling with a manual scaling plan that requires an administrator to adjust the desired capacity.

Question 7

A company has a production RDS MySQL instance with 500 GB of gp2 storage. The database experiences high read traffic. The SysOps team needs to improve read performance at minimal cost. What should they do?

Accepted Answer

Create one or more RDS Read Replicas in the same region and direct read traffic to them.. Option A is correct because adding Read Replicas offloads read queries from the primary instance, improving performance cost-effectively. Option B is wrong because migrating to Aurora is more expensive. Option C is wrong because gp3 might not provide enough IOPS for read-heavy workloads. Option D is wrong because vertical scaling is more costly than horizontal scaling.

Answer

Migrate the database to Amazon Aurora with Auto Scaling enabled.

Answer

Change the storage type to gp3 and increase IOPS.

Answer

Upgrade the DB instance to a larger instance type with more vCPUs.

Question 8

A company uses AWS Lambda functions to process messages from an SQS queue. The Lambda function is configured with a reserved concurrency of 100. The SQS queue receives unpredictable spikes of up to 10,000 messages per second. The function takes about 1 second to process a message. The SysOps team notices that during spikes, messages are being throttled and appear in the DLQ. How can the team resolve this while optimizing cost?

Accepted Answer

Increase reserved concurrency to 1000 and enable batch processing with a batch size of 10 in the SQS event source mapping.. Option D is correct because increasing reserved concurrency allows Lambda to scale to handle the spike, and using batch processing reduces the number of invocations, lowering cost. Option A is wrong because reducing concurrency would worsen throttling. Option B is wrong because a larger instance type might not be available and increases cost per invocation. Option C is wrong because Lambda cannot be run on EC2 in a serverless manner.

Answer

Reduce the reserved concurrency to 10 to force the function to process messages more slowly.

Answer

Provision an EC2 fleet to poll the SQS queue and invoke the Lambda function.

Answer

Increase the Lambda function memory and timeout to use a larger instance type.

Question 9

A company uses CloudFront to distribute content globally. They want to reduce data transfer costs and improve performance for users. What feature should they enable?

Accepted Answer

Enable Origin Shield to create a central caching layer.. Option B is correct because Origin Shield increases cache hit ratio by centralizing requests, reducing origin load and data transfer cost. Option A is wrong because Lambda@Edge adds processing but does not directly reduce transfer. Option C is wrong because it increases cache hits but does not reduce origin requests as effectively as Origin Shield. Option D is wrong because origin failover is for availability, not cost.

Answer

Configure multiple origins with failover.

Answer

Enable Lambda@Edge to modify requests and responses.

Answer

Increase the TTL for cache behaviors to the maximum allowed value.

Question 10

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?

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.. Option D is correct because an S3 Lifecycle policy automatically transitions objects to colder storage classes based on age. Option A is wrong because deleting data loses it. Option B is wrong because S3 Intelligent-Tiering has a monitoring cost per object. Option C is wrong because manual transitions are not scalable.

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 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.. Option B is correct because modifying the RI to a smaller size can better match the usage pattern, and using Auto Scaling with a scheduled scaling puts the instance to sleep when not needed. Option A is wrong because selling on the Reserved Instance Marketplace would lose the upfront payment and not address the over-provisioning. Option C is wrong because converting to On-Demand is more expensive for the hours used. Option D is wrong because simply stopping the instance during off-hours does not change the RI benefit; the RI will still be applied to the stopped instance (though RI cannot be applied to stopped instances; it would be wasted).

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 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.. Option A is correct because CloudWatch Logs supports log retention policies that automatically expire logs after a specified period, reducing storage costs. Option B is wrong because exporting to S3 and then using S3 Lifecycle is more complex and may incur additional costs. Option C is wrong because exporting to S3 Glacier is an option but not the most cost-effective for 7-year retention if logs are accessed rarely; however, retention policy is simpler. Option D is wrong because disabling logging is not compliant.

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 13

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.. Option A is correct because a target tracking policy automatically adjusts capacity based on demand, minimizing idle resources. Option B is wrong because step scaling can be used but is less efficient than target tracking. Option C is wrong because adding more instances increases idle capacity. Option D is wrong because fixed instance count does not adapt to demand.

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 14

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.. Option A is correct because the condition requires the storage class to be STANDARD. When no storage class is specified, the default is STANDARD, so the upload succeeds. Option B is wrong because the condition is satisfied. Option C is wrong because the default is STANDARD, not STANDARD-IA. Option D is wrong because the policy allows PutObject.

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 15

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 D are correct because stopping idle DB instances saves compute costs, and using Reserved Instances for predictable workloads reduces hourly costs. Option A is wrong because Multi-AZ increases costs. Option C is wrong because enabling deletion protection does not reduce costs. Option E is wrong because increasing backup retention 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.