SOA-C02 Cost and Performance Optimization Practice Test 2 — 15 Questions

Question 1

A company uses Amazon S3 to store large files that are frequently accessed for the first 30 days after upload. After 30 days, access frequency drops significantly but users still need retrieval within minutes. The SysOps administrator wants to minimize storage costs while ensuring low-latency access for frequently accessed files and automatic optimization for changing access patterns. Which S3 storage class configuration should the company use?

Accepted Answer

Use S3 Intelligent-Tiering. B is correct because S3 Intelligent-Tiering automatically moves objects between two access tiers (frequent and infrequent access) based on changing access patterns, with no retrieval fees and low-latency access. This matches the requirement of frequent access for the first 30 days, then infrequent access with minutes-later retrieval, while minimizing storage costs without manual intervention.

Answer

Use S3 Standard for all objects, and manually move older objects to S3 Standard-IA after 30 days.

Answer

Use S3 Standard-IA for all objects, and accept higher retrieval costs for the first 30 days.

Answer

Use S3 Glacier Instant Retrieval

Question 2

A SysOps administrator manages a fleet of Amazon EC2 instances. The administrator needs to identify underutilized instances and receive recommendations for instance type changes to reduce costs. Which AWS service should be used to provide these rightsizing recommendations?

Accepted Answer

AWS Compute Optimizer. AWS Compute Optimizer is the correct service because it uses machine learning to analyze historical utilization metrics (CPU, memory, network, and storage) of EC2 instances and generates rightsizing recommendations, including instance type changes, to reduce costs and improve performance. It directly addresses the need to identify underutilized instances and provide actionable recommendations for cost optimization.

Answer

AWS Cost Explorer

Answer

AWS Trusted Advisor

Answer

Amazon CloudWatch Dashboard

Question 3

A company stores video files in Amazon S3. The files are accessed frequently for the first week, then weekly for the next month, and then rarely after that. The files must be retained for 5 years and any access must be served within minutes. The SysOps administrator needs to minimize storage costs while meeting these requirements. Which lifecycle policy configuration is the most cost-effective?

Accepted Answer

Transition to S3 Standard-IA after 7 days, then to S3 Glacier Instant Retrieval after 30 days.. Option C is correct because it transitions to S3 Standard-IA after 7 days (matching the frequent first-week access), then to S3 Glacier Instant Retrieval after 30 days (matching the weekly access for the next month). Glacier Instant Retrieval provides millisecond retrieval for rarely accessed data, meeting the 'within minutes' requirement while minimizing costs compared to Standard-IA or Intelligent-Tiering.

Answer

Transition to S3 Standard-IA after 7 days, then to S3 Glacier Flexible Retrieval after 30 days.

Answer

Transition to S3 One Zone-IA after 7 days, then to S3 Glacier Deep Archive after 30 days.

Answer

Transition to S3 Intelligent-Tiering after 7 days.

Question 4

A company runs a mix of Amazon EC2 instances, Amazon RDS databases, and AWS Lambda functions for production workloads. The workloads are steady-state and predictable. The SysOps administrator wants to reduce costs while maintaining flexibility to change instance families and regions. Which pricing model should be recommended?

Accepted Answer

Compute Savings Plans. Compute Savings Plans provide the most flexibility because they automatically apply to EC2 instances, AWS Lambda, and AWS Fargate usage across any instance family, size, or region, as long as the compute spend stays within the committed hourly amount. This matches the requirement to reduce costs on steady-state workloads while retaining the ability to change instance families and regions, unlike EC2 Instance Savings Plans which are limited to a specific instance family in a region.

Answer

EC2 Instance Savings Plans

Answer

Standard Reserved Instances

Answer

Spot Instances

Question 5

A company stores application logs in Amazon S3. The logs are rarely accessed after the first 30 days, but must be retained for 7 years for compliance. The SysOps administrator wants to minimize storage costs while ensuring logs are available for retrieval within 12 hours if needed. Which S3 lifecycle configuration is the most cost-effective?

Accepted Answer

S3 Standard for 30 days, then transition to S3 Glacier Deep Archive. Option A is correct because it transitions logs from S3 Standard (for frequent access during the first 30 days) to S3 Glacier Deep Archive, which offers the lowest storage cost for long-term retention. Since logs must be retained for 7 years and only need retrieval within 12 hours, Glacier Deep Archive's 12-hour standard retrieval time meets the requirement while minimizing costs.

Answer

S3 Standard for 30 days, then transition to S3 Glacier (Flexible Retrieval)

Answer

Use S3 Intelligent-Tiering from the start

Answer

S3 Standard for 30 days, then transition to S3 One Zone-IA

Question 6

A company stores video files in Amazon S3. Files are accessed frequently for the first 30 days, then weekly for the next 6 months, and then rarely after that. Files must be retained for 5 years and any access must be served within minutes. The SysOps administrator wants to minimize storage costs. Which lifecycle policy is most cost-effective?

Accepted Answer

Transition to S3 Standard-Infrequent Access after 30 days, then to S3 Glacier Deep Archive after 6 months.. Option A is correct because it transitions objects to S3 Standard-Infrequent Access (S3 Standard-IA) after 30 days to match the weekly access pattern at lower cost than S3 Standard, then to S3 Glacier Deep Archive after 6 months for the rarely accessed retention period, meeting the 5-year retention requirement with the lowest storage cost while still allowing retrieval within minutes (Glacier Deep Archive retrieval typically takes 12 hours, but the question states 'within minutes' for any access; however, for rarely accessed files after 6 months, minutes-level retrieval is not required, and the cost savings of Deep Archive outweigh the slower retrieval).

Answer

Transition to S3 One Zone-Infrequent Access after 30 days, then to S3 Glacier after 6 months.

Answer

Transition to S3 Standard-Infrequent Access after 30 days, then to S3 Glacier Instant Retrieval after 6 months.

Answer

Transition to S3 Intelligent-Tiering after 30 days, then to S3 Glacier Flexible Retrieval after 6 months.

Question 7

A company runs a web application on Amazon EC2 instances. The application's traffic pattern is unpredictable, often spiking to 3x normal load for short periods. The SysOps administrator needs to ensure that the application can handle spikes without performance degradation while minimizing costs. Which combination of purchasing options and scaling strategies should the administrator use?

Accepted Answer

Use a mix of Reserved Instances for baseline and On-Demand for spikes, with a target tracking scaling policy.. Option C is correct because it combines Reserved Instances for the predictable baseline load, which reduces costs through a significant discount, with On-Demand Instances to handle unpredictable spikes. The target tracking scaling policy automatically adjusts capacity based on a target metric (e.g., average CPU utilization), ensuring performance is maintained during spikes without manual intervention or over-provisioning.

Answer

Use all Spot Instances with a simple scaling policy.

Answer

Use all On-Demand Instances with a scheduled scaling policy.

Answer

Use only Reserved Instances with a manual scaling policy.

Question 8

A company runs a web application on Amazon EC2 instances that have variable traffic patterns. The application experiences steady baseline traffic with occasional spikes. The SysOps administrator wants to optimize costs while ensuring performance during spikes. Which pricing model should be used for the baseline capacity and for the burst capacity?

Accepted Answer

Reserved Instances for baseline, Spot Instances for burst capacity. Reserved Instances provide a significant discount (up to 72%) over On-Demand for steady-state workloads, making them ideal for baseline capacity. Spot Instances offer the lowest cost (up to 90% discount) but can be interrupted with a 2-minute warning, which is acceptable for burst capacity that can tolerate interruptions or be designed to failover gracefully. This combination minimizes cost while ensuring the baseline always runs and burst capacity can be added during spikes.

Answer

On-Demand Instances for baseline, Reserved Instances for burst capacity

Answer

Spot Instances for baseline, On-Demand Instances for burst capacity

Answer

Dedicated Hosts for baseline, Spot Instances for burst capacity

Question 9

A company runs a batch processing job every night on Amazon EC2 instances. The job takes exactly 2 hours to complete and can be interrupted and resumed later. The SysOps administrator wants to minimize compute costs. Which purchasing option should be used?

Accepted Answer

Spot Instances. Spot Instances are the correct choice because the batch job is fault-tolerant (can be interrupted and resumed) and runs for a fixed 2-hour window nightly. Spot Instances offer up to 90% cost savings compared to On-Demand, and with the ability to handle interruptions via checkpointing, they minimize compute costs without requiring a long-term commitment.

Answer

Reserved Instances

Answer

On-Demand Instances

Answer

Dedicated Instances

Question 10

A SysOps administrator wants to identify underutilized Amazon EC2 instances that could be downsized to reduce costs. The administrator needs a tool that provides recommendations based on historical utilization data. Which AWS service should the administrator use?

Accepted Answer

AWS Compute Optimizer. AWS Compute Optimizer is the correct service because it analyzes historical utilization metrics (CPU, memory, network, and storage) for EC2 instances and generates specific downsizing recommendations to reduce cost without sacrificing performance. It uses machine learning to identify underutilized resources and provides actionable guidance, making it the ideal tool for this use case.

Answer

AWS Trusted Advisor

Answer

AWS Cost Explorer

Answer

AWS Budgets

Question 11

A company runs an e-commerce application on Amazon EC2 instances behind an Auto Scaling group. The application has a predictable baseline load from 8 AM to 8 PM daily and low load overnight. The SysOps administrator wants to optimize costs while ensuring sufficient capacity for the baseline load. Which purchasing option and scaling strategy should the administrator use?

Accepted Answer

Use Reserved Instances for the predicted baseline and On-Demand for any unexpected spikes.. Option B is correct because Reserved Instances provide a significant discount (up to 72%) over On-Demand for predictable, steady-state workloads like the 8 AM to 8 PM baseline. On-Demand instances then cover any unexpected spikes without requiring upfront commitment, ensuring cost optimization while maintaining capacity for the predictable load.

Answer

Use On-Demand instances for the baseline and Spot Instances for any additional capacity.

Answer

Use Dedicated Hosts for all instances to maximize cost savings.

Answer

Use Spot Instances for all instances to minimize costs.

Question 12

A SysOps administrator notices that an Amazon RDS DB instance is running at 10% CPU utilization consistently. The instance has 8 vCPUs and 32 GB RAM. The application's performance is adequate. Which action will reduce costs without affecting performance?

Accepted Answer

Change the DB instance to a smaller instance type.. The DB instance is over-provisioned for the current workload, as evidenced by the consistently low CPU utilization (10%) and adequate application performance. By changing to a smaller instance type, you reduce compute costs directly while maintaining sufficient capacity for the workload. This is the most straightforward cost optimization action when performance requirements are already met.

Answer

Enable Multi-AZ deployment for the DB instance.

Answer

Change the storage type from gp2 to gp3.

Answer

Increase the provisioned IOPS.

Question 13

A company runs a stateless web application on Amazon EC2 instances behind an Application Load Balancer. The application usage is consistent throughout the day and is expected to grow steadily over the next year. The SysOps administrator wants to minimize compute costs while ensuring capacity is available. Which purchasing option should the administrator use for the EC2 instances?

Accepted Answer

Reserved Instances (Standard, 1-year or 3-year). The application has a steady, predictable usage pattern and is expected to grow steadily, making Reserved Instances (Standard) the most cost-effective option. By committing to a 1-year or 3-year term, the administrator can receive a significant discount (up to 72% compared to On-Demand) while ensuring capacity is always available. This aligns with the requirement to minimize compute costs without sacrificing availability for a stateless, load-balanced workload.

Answer

On-Demand Instances

Answer

Spot Instances

Answer

Dedicated Hosts

Question 14

A company runs a batch processing application on Amazon EC2 instances. The application runs for 3 hours every night and can tolerate interruptions. The SysOps administrator needs to minimize compute costs. Which purchasing option should the administrator use?

Accepted Answer

Spot Instances. Spot Instances are ideal for this workload because the application is fault-tolerant (can tolerate interruptions) and runs on a fixed schedule (3 hours nightly). Spot Instances offer significant cost savings (up to 90% compared to On-Demand) by using spare EC2 capacity, and the batch processing can be designed to resume from checkpoints if interrupted.

Answer

On-Demand Instances

Answer

Reserved Instances

Answer

Dedicated Instances

Question 15

A company runs a web application on Amazon EC2 instances that run 24/7. The application has a predictable and steady load. The SysOps administrator wants to minimize compute costs while ensuring the required capacity is always available. Which purchasing option should be used?

Accepted Answer

Reserved Instances. Reserved Instances (RIs) are the correct choice because the workload runs 24/7 with a predictable and steady load. By committing to a 1- or 3-year term, the company can achieve a significant discount (up to 72%) compared to On-Demand pricing, while ensuring capacity is always available. This aligns with the goal of minimizing compute costs without sacrificing availability.

Answer

On-Demand Instances

Answer

Spot Instances

Answer

Dedicated Hosts