SOA-C02 Cost and Performance Optimization Practice Test 8 — 15 Questions

Question 1

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?

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

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 2

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 3

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 4

A company runs a web application on EC2 instances behind an Application Load Balancer. The application experiences unpredictable traffic spikes. Which AWS service should be used to automatically adjust the number of EC2 instances based on demand, optimizing cost and performance?

Accepted Answer

AWS Auto Scaling. AWS Auto Scaling is the correct service because it automatically adjusts the number of EC2 instances in response to demand, using scaling policies based on metrics like CPU utilization or request count. This ensures that the application can handle traffic spikes without manual intervention, optimizing both cost (by scaling down during low demand) and performance (by scaling up during spikes). The service integrates directly with the Application Load Balancer to register and deregister instances as needed.

Answer

Amazon CloudWatch

Answer

Elastic Load Balancing

Answer

AWS Lambda

Question 5

A SysOps administrator needs to reduce costs for an Amazon RDS for MySQL DB instance that is used for development. The instance is only needed during business hours (9 AM to 5 PM) on weekdays. Which solution is the MOST cost-effective while maintaining the ability to start and stop the instance on a schedule?

Accepted Answer

Use AWS Instance Scheduler to stop and start the RDS instance on a schedule.. AWS Instance Scheduler is a fully managed solution designed specifically to start and stop RDS instances on a defined schedule, such as weekdays from 9 AM to 5 PM. This eliminates compute costs during non-business hours while preserving the instance's storage and configuration, making it the most cost-effective and reliable approach for a development environment.

Answer

Create a read replica and promote it when needed.

Answer

Purchase a reserved instance for the DB instance.

Answer

Use a Lambda function to stop the instance at 5 PM and start it at 9 AM on weekdays.

Question 6

Which THREE AWS services can be used to monitor and optimize costs? (Choose THREE.)

Accepted Answer

AWS Trusted Advisor. AWS Trusted Advisor provides cost optimization recommendations by analyzing your AWS environment and identifying idle resources, underutilized instances, and reserved instance opportunities. It offers specific checks like 'Low Utilization Amazon EC2 Instances' and 'Idle Load Balancers' that directly help reduce spending.

Answer

AWS Shield

Answer

AWS CloudFormation

Question 7

Which TWO configurations can improve the performance of an Amazon RDS for PostgreSQL database that is experiencing high read latency? (Choose TWO.)

Accepted Answer

Enable provisioned IOPS on the DB instance.. Enabling Provisioned IOPS on an Amazon RDS for PostgreSQL database provides consistent and predictable I/O performance, which directly reduces read latency by ensuring sufficient IOPS for read-intensive workloads. Option C is correct because creating a read replica offloads read traffic from the primary DB instance to the replica, reducing contention and improving read latency for the primary instance.

Answer

Upgrade to a larger instance size.

Answer

Enable Multi-AZ deployment.

Answer

Enable storage auto-scaling.

Question 8

A SysOps administrator notices that an EC2 instance's CPU utilization is consistently above 90% during peak hours. Which action will improve performance without over-provisioning resources?

Accepted Answer

Change the instance type to a larger size, such as moving from t3.medium to t3.large.. Changing the instance type to a larger size (e.g., from t3.medium to t3.large) vertically scales the instance, providing more vCPUs and memory to handle the increased CPU load during peak hours. This directly addresses the high CPU utilization without over-provisioning, as you are only scaling up the specific resource that is constrained. Spot Instances (A) do not improve performance; they offer lower cost but same performance. Increasing EBS volumes (B) does not affect CPU performance. Auto Scaling (D) adds more instances (horizontal scaling), which can over-provision if the single instance's capacity is sufficient after a vertical scale-up.

Answer

Use Spot Instances instead of On-Demand.

Answer

Increase the number of EBS volumes attached to the instance.

Answer

Configure Auto Scaling to add more instances during peak hours.

Question 9

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 10

A SysOps administrator needs to reduce costs for a fleet of EC2 instances that run a stateless web application. The instances are currently On-Demand. The workload runs 24/7 for the next 12 months. Which pricing model provides the greatest cost savings?

Accepted Answer

Purchase Standard Reserved Instances for a 1-year term.. Standard Reserved Instances (RIs) for a 1-year term provide a significant discount (up to 40%) over On-Demand pricing for workloads that run continuously 24/7. Since this stateless web application runs constantly for the next 12 months, Standard RIs offer the greatest cost savings among the options, as they are designed for steady-state usage and do not require flexibility in instance family or operating system.

Answer

Use Dedicated Hosts.

Answer

Use Spot Instances.

Answer

Purchase Convertible Reserved Instances for a 1-year term.

Question 11

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 12

Which THREE AWS features can be used to improve the performance of an Amazon DynamoDB table that is experiencing high read latency? (Choose THREE.)

Accepted Answer

Enable DynamoDB Accelerator (DAX).. DynamoDB Accelerator (DAX) is a fully managed, highly available, in-memory cache that can reduce DynamoDB response times from milliseconds to microseconds. By caching frequently read items, DAX offloads read requests from the underlying table, directly addressing high read latency without requiring additional read capacity units or table modifications.

Answer

Enable Auto Scaling for read capacity.

Answer

Use Time to Live (TTL) to delete old items.

Question 13

A company runs a critical application on EC2 instances in an Auto Scaling group behind an Application Load Balancer. The application requires very low latency and high availability. The SysOps administrator notices that the application experiences increased latency during traffic spikes even though the Auto Scaling group is scaling out. Which solution would MOST effectively reduce latency?

Accepted Answer

Change the launch configuration to use a larger instance type with more CPU and memory.. Using a larger instance type with more CPU and memory directly addresses the root cause of increased latency during traffic spikes: the existing instances are resource-constrained under load. By provisioning instances with higher compute capacity, each instance can handle more requests per second, reducing queueing delays and per-request processing time. This is a more immediate and effective solution than scaling out alone, which adds instances but does not improve the performance of each individual instance.

Answer

Pre-warm the load balancer by contacting AWS Support.

Answer

Increase the Auto Scaling cooldown period.

Answer

Deploy the instances in multiple Availability Zones.

Question 14

A SysOps administrator notices that the monthly bill for Amazon RDS is higher than expected. The environment includes multiple DB instances with low CPU and memory utilization. Which action will most effectively reduce costs while maintaining performance?

Accepted Answer

Resize the DB instances to a smaller instance class. The DB instances have low CPU and memory utilization, indicating they are over-provisioned. Resizing to a smaller instance class directly reduces the hourly compute cost without affecting performance, as the current workload does not require the larger instance's capacity.

Answer

Enable Multi-AZ deployment for high availability

Answer

Delete unused RDS snapshots

Answer

Provisioned IOPS (io1) storage for better performance

Question 15

A SysOps team is using CloudWatch to monitor CPU utilization of EC2 instances. They want to receive a notification when average CPU exceeds 80% for 5 consecutive minutes. Which combination of services should they use?

Accepted Answer

CloudWatch Metrics, CloudWatch Alarm, and Amazon SNS. CloudWatch Metrics collects the CPU utilization data from EC2 instances, a CloudWatch Alarm evaluates whether the average CPU exceeds 80% for 5 consecutive minutes (using a period of 300 seconds and 5 datapoints), and Amazon SNS publishes the notification to subscribers (e.g., email, SMS) when the alarm state transitions to ALARM. This combination directly fulfills the requirement without unnecessary services.

Answer

CloudWatch Metrics, CloudWatch Alarm, and AWS Lambda

Answer

AWS Config, CloudWatch Alarm, and Amazon SNS

Answer

CloudWatch Logs, CloudWatch Alarm, and AWS Lambda