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

Question 1

A company is running a critical application on Amazon RDS for MySQL. The database is experiencing high read traffic, causing performance issues. The SysOps administrator needs to improve read performance while keeping costs low. Which solution should the administrator choose?

Accepted Answer

Add one or more Read Replicas in the same Region. Option A is correct because adding Read Replicas offloads read traffic from the primary DB, improving performance at low cost. Multi-AZ is for high availability, not read scaling. Larger instance class increases cost. ElastiCache can help but may be overkill and adds complexity and cost.

Answer

Enable Multi-AZ deployment

Answer

Increase the DB instance class to a larger size

Answer

Use Amazon ElastiCache to cache read results

Question 2

A company stores log files in Amazon S3. The logs are accessed frequently for the first 30 days, then rarely after that. The company wants to automatically transition objects to a lower-cost storage class after 30 days. Which S3 feature should be configured?

Accepted Answer

S3 Lifecycle rule. Option D is correct because S3 Lifecycle rules automate transitions between storage classes. S3 Versioning is for object versions. S3 Object Lock is for retention. S3 Transfer Acceleration speeds up uploads.

Answer

S3 Versioning

Answer

S3 Transfer Acceleration

Answer

S3 Object Lock

Question 3

A company is using Amazon S3 to store media files. The files are accessed frequently for the first 90 days, then rarely after that. The company wants to optimize storage costs. Which TWO actions should the SysOps administrator take? (Choose two.)

Accepted Answer

Configure a lifecycle policy to delete incomplete multipart uploads after 7 days. Option A and Option D are correct. A lifecycle policy to transition to S3 Standard-IA after 90 days reduces cost for infrequent access. Deleting incomplete multipart uploads prevents orphaned parts from incurring storage costs. Option B is wrong because enabling versioning may increase costs. Option C is wrong because S3 Object Lock does not help with cost. Option E is wrong because Requester Pays shifts costs but not storage optimization.

Answer

Enable S3 Object Lock to prevent deletion

Answer

Enable S3 Versioning to keep multiple versions

Answer

Enable Requester Pays on the bucket

Question 4

A SysOps administrator is designing a cost-effective architecture for a batch processing workload that runs once per day and can tolerate interruptions. The workload uses EC2 instances. Which TWO purchasing options should the administrator consider? (Choose two.)

Accepted Answer

Spot Instances. Option B and Option D are correct. Spot Instances are ideal for fault-tolerant, interruptible workloads at a steep discount. On-Demand Instances can be used as a fallback if Spot capacity is unavailable. Option A is wrong because Reserved Instances require a 1- or 3-year commitment for a once-daily job. Option C is wrong because Dedicated Hosts are expensive. Option E is wrong because Capacity Reservations incur costs even when not running.

Answer

Dedicated Hosts

Answer

Reserved Instances (Standard)

Answer

Capacity Reservations

Question 5

A company runs a production database on Amazon RDS for PostgreSQL. The SysOps administrator wants to improve query performance for a read-heavy application without increasing costs significantly. Which THREE actions should the administrator take? (Choose three.)

Accepted Answer

Optimize slow queries by reviewing the slow query log. Option C is correct because reviewing the slow query log in RDS for PostgreSQL allows the administrator to identify and optimize poorly performing queries, which directly improves query performance without incurring additional infrastructure costs. This is a standard performance tuning practice that targets the root cause of read-heavy application slowdowns.

Answer

Enable Multi-AZ deployment

Answer

Increase the allocated storage size

Question 6

A company runs a production web application on Amazon EC2 instances behind an Application Load Balancer. The application experiences variable traffic patterns, with peak usage during business hours. The company wants to optimize costs while maintaining performance. What should the SysOps administrator do?

Accepted Answer

Use a combination of On-Demand and Spot Instances, with On-Demand for baseline traffic and Spot for burst capacity.. The correct answer is B. A mixed pricing model with Spot Instances for flexible workloads and On-Demand for steady-state traffic can significantly reduce costs while ensuring availability. Option A is wrong because Reserved Instances require a 1- or 3-year commitment and are not suitable for variable traffic. Option C is wrong because Dedicated Hosts are expensive and not needed. Option D is wrong because increasing instance size without right-sizing may lead to over-provisioning and increased costs.

Answer

Increase the EC2 instance sizes to handle peak load at all times.

Answer

Purchase Reserved Instances for all instances to get the lowest hourly rate.

Answer

Use Dedicated Hosts to ensure consistent performance.

Question 7

A SysOps administrator is troubleshooting a cost overrun in an AWS account. The cost explorer shows that data transfer costs have significantly increased. The architecture includes an Application Load Balancer (ALB) internet-facing, EC2 instances in private subnets, and an S3 bucket for static assets. Which action will MOST effectively reduce data transfer costs?

Accepted Answer

Implement a VPC Gateway Endpoint for S3 so that traffic from EC2 to S3 stays within the AWS network.. The correct answer is D. Data transfer from EC2 to S3 within the same region is free when using a VPC endpoint (gateway endpoint). Option A is wrong because CloudFront reduces latency but does not eliminate data transfer costs from ALB to EC2. Option B is wrong because moving to private ALB would require a VPN and may increase costs. Option C is wrong because NAT Gateway charges for data processing and transfer.

Answer

Enable Amazon CloudFront to cache static assets and reduce direct requests to the ALB.

Answer

Replace the NAT Gateway with a NAT instance to reduce hourly charges.

Answer

Change the ALB to internal (private) and use AWS Direct Connect for user access.

Question 8

A company is running a stateful web application on a single EC2 instance with a 500 GB gp2 EBS volume. The instance is currently at 80% CPU and memory utilization during peak hours. The company wants to improve performance and scalability without incurring high costs. What should the SysOps administrator do?

Accepted Answer

Implement an Application Load Balancer with an Auto Scaling group to distribute traffic across multiple instances.. The correct answer is B. Using an Application Load Balancer and Auto Scaling group allows the application to scale out based on demand, improving performance and cost efficiency. Option A is wrong because vertical scaling may cause downtime and is limited. Option C is wrong because converting to gp3 provides performance at lower cost but does not address scalability. Option D is wrong because increasing swap space is a temporary fix and does not improve performance.

Answer

Upgrade the instance to a larger size (vertical scaling).

Answer

Increase the swap space on the instance to handle memory pressure.

Answer

Migrate the EBS volume from gp2 to gp3 to improve I/O performance.

Question 9

A company has a production RDS for PostgreSQL database with a db.r5.large instance. The database experiences high read traffic during business hours. The SysOps administrator needs to improve read performance and ensure high availability at minimal cost. Which solution should the administrator implement?

Accepted Answer

Create a Multi-AZ deployment and then add a Read Replica in a different Availability Zone.. The correct answer is A. A Multi-AZ deployment with a Read Replica in another AZ provides both high availability and read scaling. Option B is wrong because increasing instance size is costly and does not provide HA. Option C is wrong because Multi-AZ alone does not offload read queries. Option D is wrong because ElastiCache adds complexity and cost, and is not directly a database solution.

Answer

Upgrade the instance to db.r5.xlarge and enable automatic backups.

Answer

Enable Multi-AZ on the existing instance to provide automatic failover but no read scaling.

Answer

Use Amazon ElastiCache for Redis to cache frequent queries.

Question 10

A SysOps administrator is reviewing AWS Cost Explorer and notices that data transfer costs from EC2 to the internet are high. The EC2 instances are in a VPC with a NAT Gateway in a public subnet. The route table for private subnets sends 0.0.0.0/0 traffic to the NAT Gateway. The application serves content to users over the internet. Which change will LEAST impact application performance while reducing costs?

Accepted Answer

Purchase a Dedicated NAT Gateway in the same region to get lower data processing rates.. The correct answer is C. Purchasing a Dedicated NAT Gateway in the same region does not reduce costs; the NAT Gateway itself incurs costs. Option A is wrong because reducing NAT Gateway size limits throughput and may impact performance. Option B is wrong because an egress-only Internet Gateway is for IPv6 only. Option D is wrong because using a VPC Gateway Endpoint for S3 reduces costs for S3 traffic but not general internet traffic.

Answer

Replace the NAT Gateway with a smaller NAT Gateway to reduce hourly charges.

Answer

Use an egress-only Internet Gateway for the private subnets.

Answer

Implement a VPC Gateway Endpoint for Amazon S3 to keep S3 traffic within AWS.

Question 11

A company runs a batch processing job on a single EC2 instance that runs for 2 hours every night. The job is fault-tolerant and can be interrupted. The SysOps administrator wants to minimize compute costs. What is the MOST cost-effective solution?

Accepted Answer

Use a Spot Instance that can be interrupted but is significantly cheaper.. A Spot Instance is the most cost-effective choice because the job is fault-tolerant and can be interrupted, allowing you to leverage unused AWS EC2 capacity at up to 90% discount compared to On-Demand pricing. Since the job runs for only 2 hours nightly and can handle interruptions, Spot Instances provide the lowest compute cost while meeting the workload requirements.

Answer

Use an On-Demand instance to ensure the job runs every night.

Answer

Purchase a Reserved Instance for 1 year to get a discount.

Answer

Launch a Dedicated Host to ensure consistent performance.

Question 12

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.. The correct answer is D. This policy transitions objects to cost-effective storage classes based on access patterns. Option A is wrong because logs should be moved to Glacier Deep Archive for long-term retention. Option B is wrong because logs are rarely accessed but need retention, so moving to S3 Standard-IA is insufficient cost savings. Option C is wrong because user uploads should not be immediately archived; they are accessed frequently initially.

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 13

A company uses Amazon CloudWatch Logs to store application logs from EC2 instances. The log volume is 100 GB per day, and logs are retained for 1 year. The SysOps administrator wants to reduce costs while maintaining compliance. Which solution is MOST effective?

Accepted Answer

Export logs to Amazon S3 and configure a lifecycle policy to transition them to Glacier Deep Archive after 30 days.. The correct answer is B. Exporting logs to S3 and using S3 lifecycle policies to transition to cheaper storage classes (e.g., Glacier Deep Archive) is cost-effective for long-term retention. Option A is wrong because CloudWatch Logs Insights is a query tool, not a cost reduction method. Option C is wrong because reducing retention period violates compliance. Option D is wrong because disabling encryption does not reduce costs significantly and may violate security policies.

Answer

Reduce the log retention period to 30 days.

Answer

Disable server-side encryption for the log group to reduce overhead.

Answer

Use CloudWatch Logs Insights to query logs instead of storing them.

Question 14

A company has a web application running on EC2 instances behind an Application Load Balancer. The application experiences latency spikes during peak hours. Amazon CloudWatch metrics show that CPU and memory are not fully utilized. The SysOps administrator suspects the bottleneck is the database. The database is an RDS for MySQL instance. Which action should the administrator take to improve performance without over-provisioning?

Accepted Answer

Enable RDS Performance Insights to analyze database load and identify slow queries.. The correct answer is B. RDS Performance Insights helps identify database bottlenecks (e.g., slow queries, locks). Option A is wrong because increasing instance size may not address the root cause. Option C is wrong because Multi-AZ improves availability but not performance. Option D is wrong because Read Replicas help with read traffic but not if the bottleneck is writes or locking.

Answer

Add a Read Replica to offload read queries.

Answer

Convert the RDS instance to a Multi-AZ deployment.

Answer

Increase the RDS instance size to the next tier.

Question 15

A SysOps administrator is optimizing costs for an AWS account. The account has multiple EC2 instances running 24/7 with varying utilization. Which TWO actions will help reduce costs without impacting performance? (Choose TWO.)

Accepted Answer

Use AWS Compute Optimizer to right-size instances.. The correct answers are A and D. Converting to reserved instances provides significant discount for steady-state workloads. Right-sizing instances based on CloudWatch metrics ensures you are not over-provisioned. Option B is wrong because increasing instance size increases costs. Option C is wrong because disabling termination protection does not affect costs. Option E is wrong because detailed monitoring incurs additional charges.

Answer

Use larger instance types to improve performance.

Answer

Enable detailed CloudWatch monitoring for all instances.

Answer

Enable termination protection on all instances.