Amazon AWS SAA-C03 Cost-Optimized Compute, Purchasing Models, Rightsizing, and Elasticity Practice Test 1

 

Topic 18 Practice Test 1 covers Cost-Optimized Compute, Purchasing Models, Rightsizing, and Elasticity for AWS SAA-C03. For broader exam preparation, review the AWS SAA-C03 Exam Dumps. Every option includes focused technical reasoning explaining both the AWS architecture concept and its fit to the scenario.

Question 1

A company runs EC2 in several Regions today and expects some services to move to Fargate and Lambda next year. Its base compute spend is stable. An architect needs to discount the steady compute spend without locking the organization to one EC2 family or Region. What should be selected? Choose ONE.

1. EC2 Instance Savings Plans
2. Zonal Standard Reserved Instance
3. Compute Savings Plans
4. On-Demand Instances

Correct Answer(s)

 

C

Rationale

1. EC2 Instance Savings Plans discount usage within one EC2 instance family in a selected Region. It is appropriate when steady EC2 use stays in one family and Region while size may change. This scenario prioritizes commitment flexibility: the design must discount the steady compute spend without locking the organization to one EC2 family or Region. The mismatch makes it less suitable.
2. Zonal Standard Reserved Instance combines an EC2 billing discount with reserved capacity for matching zonal attributes. It is appropriate when steady EC2 demand also requires capacity assurance in one Availability Zone. This scenario prioritizes commitment flexibility: the design must discount the steady compute spend without locking the organization to one EC2 family or Region. The mismatch makes it less suitable.
3. Compute Savings Plans reduce eligible EC2, Fargate, and Lambda charges through a flexible hourly spend commitment. Compute Savings Plans retain coverage across EC2 families and Regions and also cover eligible Fargate and Lambda usage. It meets the need to discount the steady compute spend without locking the organization to one EC2 family or Region and improves commitment flexibility.
4. On-Demand Instances bill EC2 capacity as it is consumed without requiring a multi-year pricing commitment. It is appropriate when the workload is temporary, uncertain, or cannot accept Spot interruption. This scenario prioritizes commitment flexibility: the design must discount the steady compute spend without locking the organization to one EC2 family or Region. The mismatch makes it less suitable.

 

Question 2

A rendering service will use the C family in us-east-1 continuously for three years, but instance sizes may change as jobs evolve. Which change most directly allows the workload to maximize commitment savings while staying within one EC2 family and Region? Choose ONE.

1. EC2 Instance Savings Plans
2. Compute Savings Plans
3. On-Demand Instances
4. Spot Instances

Correct Answer(s)

 

A

Rationale

1. EC2 Instance Savings Plans discount usage within one EC2 instance family in a selected Region. An EC2 Instance Savings Plan matches the fixed family and Region while allowing size changes, trading some flexibility for stronger discount potential. It meets the need to maximize commitment savings while staying within one EC2 family and Region and improves committed EC2 rate.
2. Compute Savings Plans apply a committed-rate discount across qualifying EC2 usage and eligible serverless or container compute. It is appropriate when the organization wants one commitment to follow changing compute choices. This scenario prioritizes committed EC2 rate: the design must maximize commitment savings while staying within one EC2 family and Region. The mismatch makes it less suitable.
3. On-Demand Instances provide noninterruptible EC2 usage with no one- or three-year spend obligation. It is appropriate when future demand is unclear and purchase flexibility is more valuable than commitment discounts. This scenario prioritizes committed EC2 rate: the design must maximize commitment savings while staying within one EC2 family and Region. The mismatch makes it less suitable.
4. Spot Instances lower EC2 compute price by accepting reclaimable spare-capacity instances. It is appropriate when the application is designed to survive instance interruption without losing critical state. This scenario prioritizes committed EC2 rate: the design must maximize commitment savings while staying within one EC2 family and Region. The mismatch makes it less suitable.

 

Question 3

A trading system must launch a fixed number of matching instances in one Availability Zone every day and will run them continuously for years. Which cost-optimization decision best meets the requirement to obtain a long-term discount and reserve matching zonal capacity? Choose ONE.

1. Compute Savings Plans
2. EC2 Instance Savings Plans
3. On-Demand Capacity Reservation plus Savings Plan
4. Zonal Standard Reserved Instance

Correct Answer(s)

 

D

Rationale

1. Compute Savings Plans trade an hourly usage commitment for broad compute discounts spanning EC2, Fargate, and Lambda. It is appropriate when long-lived compute has a stable floor but workload placement can change. This scenario prioritizes zonal cost and capacity: the design must obtain a long-term discount and reserve matching zonal capacity. The mismatch makes it less suitable.
2. EC2 Instance Savings Plans discount usage within one EC2 instance family in a selected Region. It is appropriate when steady EC2 use stays in one family and Region while size may change. This scenario prioritizes zonal cost and capacity: the design must obtain a long-term discount and reserve matching zonal capacity. The mismatch makes it less suitable.
3. On-Demand Capacity Reservation plus Savings Plan pairs zonal capacity assurance with a separate eligible usage discount. It is appropriate when exact zonal capacity must be held while long-term compute usage also merits a discount. This scenario prioritizes zonal cost and capacity: the design must obtain a long-term discount and reserve matching zonal capacity. The mismatch makes it less suitable.
4. Zonal Standard Reserved Instance combines an EC2 billing discount with reserved capacity for matching zonal attributes. The requirement couples predictable long-term usage with matching zonal capacity, which is the distinctive combination offered by a zonal Standard RI. It meets the need to obtain a long-term discount and reserve matching zonal capacity and improves zonal cost and capacity.

 

Question 4

A startup is testing a new service for six weeks. Traffic is unpredictable, the architecture may change, and requests cannot be interrupted. The architecture must avoid long-term commitment while retaining noninterruptible EC2 capacity. Which option is most cost-effective? Choose ONE.

1. Spot Instances
2. On-Demand Instances
3. EC2 Instance Savings Plans
4. Compute Savings Plans

Correct Answer(s)

 

B

Rationale

1. Spot Instances use discounted spare EC2 capacity that AWS may reclaim with interruption notice. It is appropriate when workers are fault tolerant and can retry, checkpoint, or redistribute unfinished work. This scenario prioritizes short-term cost risk: the design must avoid long-term commitment while retaining noninterruptible EC2 capacity. The mismatch makes it less suitable.
2. On-Demand Instances bill EC2 capacity as it is consumed without requiring a multi-year pricing commitment. On-Demand avoids committing to a usage pattern that may disappear or change while keeping instances free from Spot interruption behavior. It meets the need to avoid long-term commitment while retaining noninterruptible EC2 capacity and improves short-term cost risk.
3. EC2 Instance Savings Plans discount usage within one EC2 instance family in a selected Region. It is appropriate when steady EC2 use stays in one family and Region while size may change. This scenario prioritizes short-term cost risk: the design must avoid long-term commitment while retaining noninterruptible EC2 capacity. The mismatch makes it less suitable.
4. Compute Savings Plans reduce eligible EC2, Fargate, and Lambda charges through a flexible hourly spend commitment. It is appropriate when baseline compute spend is predictable while the exact service, family, or Region can vary. This scenario prioritizes short-term cost risk: the design must avoid long-term commitment while retaining noninterruptible EC2 capacity. The mismatch makes it less suitable.

 

Question 5

A genomics pipeline can checkpoint every few minutes, retries failed tasks automatically, and has no fixed completion deadline. An architect needs to minimize EC2 price for interruption-tolerant workers. What should be selected? Choose ONE.

1. On-Demand Instances
2. Spot Instances
3. Zonal Standard Reserved Instance
4. Compute Savings Plans

Correct Answer(s)

 

B

Rationale

1. On-Demand Instances provide noninterruptible EC2 usage with no one- or three-year spend obligation. It is appropriate when future demand is unclear and purchase flexibility is more valuable than commitment discounts. This scenario prioritizes batch compute price: the design must minimize EC2 price for interruption-tolerant workers. The mismatch makes it less suitable.
2. Spot Instances lower EC2 compute price by accepting reclaimable spare-capacity instances. The workload explicitly tolerates interruption and retry, so it can exchange guaranteed continuity for the lower price of spare EC2 capacity. It meets the need to minimize EC2 price for interruption-tolerant workers and improves batch compute price.
3. Zonal Standard Reserved Instance combines an EC2 billing discount with reserved capacity for matching zonal attributes. It is appropriate when steady EC2 demand also requires capacity assurance in one Availability Zone. This scenario prioritizes batch compute price: the design must minimize EC2 price for interruption-tolerant workers. The mismatch makes it less suitable.
4. Compute Savings Plans apply a committed-rate discount across qualifying EC2 usage and eligible serverless or container compute. It is appropriate when the organization wants one commitment to follow changing compute choices. This scenario prioritizes batch compute price: the design must minimize EC2 price for interruption-tolerant workers. The mismatch makes it less suitable.

 

Question 6

A Spot fleet can use many instance types. Lowest-price pools produce frequent interruptions that erase much of the savings through rework. Which change most directly allows the workload to select Spot pools using both price and available capacity? Choose ONE.

1. Spot Instances
2. Flexible EC2 instance types in a Spot group
3. On-Demand Instances
4. Price-capacity-optimized Spot allocation

Correct Answer(s)

 

D

Rationale

1. Spot Instances supply substantially discounted EC2 capacity in exchange for interruption tolerance. It is appropriate when queued or distributed jobs can resume elsewhere when capacity is reclaimed. This scenario prioritizes effective Spot cost: the design must select Spot pools using both price and available capacity. The mismatch makes it less suitable.
2. Flexible EC2 instance types in a Spot group expands eligible Spot capacity pools by allowing several equivalent instance types. It is appropriate when fault-tolerant workers can run on many shapes and need better Spot availability. This scenario prioritizes effective Spot cost: the design must select Spot pools using both price and available capacity. The mismatch makes it less suitable.
3. On-Demand Instances let teams run EC2 at standard usage rates while retaining freedom to stop or change the workload. It is appropriate when the service is short-lived or its durable baseline has not yet been established. This scenario prioritizes effective Spot cost: the design must select Spot pools using both price and available capacity. The mismatch makes it less suitable.
4. Price-capacity-optimized Spot allocation balances Spot price with pool capacity to reduce interruption exposure. The allocation strategy considers price and capacity together, reducing expensive churn while still seeking discounted Spot pools. It meets the need to select Spot pools using both price and available capacity and improves effective Spot cost.

 

Question 7

An API requires four noninterruptible workers at all times but can use interruption-tolerant workers for demand above that baseline. Which cost-optimization decision best meets the requirement to retain a stable base while purchasing burst capacity at Spot rates? Choose ONE.

1. Mixed On-Demand and Spot Auto Scaling
2. Spot Instances
3. On-Demand Instances
4. Price-capacity-optimized Spot allocation

Correct Answer(s)

 

A

Rationale

1. Mixed On-Demand and Spot Auto Scaling combines a stable On-Demand base with discounted Spot capacity above it. A mixed instances policy can preserve the required noninterruptible baseline and use discounted Spot for elastic capacity that may be replaced. It meets the need to retain a stable base while purchasing burst capacity at Spot rates and improves blended fleet cost.
2. Spot Instances use discounted spare EC2 capacity that AWS may reclaim with interruption notice. It is appropriate when workers are fault tolerant and can retry, checkpoint, or redistribute unfinished work. This scenario prioritizes blended fleet cost: the design must retain a stable base while purchasing burst capacity at Spot rates. The mismatch makes it less suitable.
3. On-Demand Instances bill EC2 capacity as it is consumed without requiring a multi-year pricing commitment. It is appropriate when the workload is temporary, uncertain, or cannot accept Spot interruption. This scenario prioritizes blended fleet cost: the design must retain a stable base while purchasing burst capacity at Spot rates. The mismatch makes it less suitable.
4. Price-capacity-optimized Spot allocation balances Spot price with pool capacity to reduce interruption exposure. It is appropriate when a flexible Spot fleet needs both savings and practical availability. This scenario prioritizes blended fleet cost: the design must retain a stable base while purchasing burst capacity at Spot rates. The mismatch makes it less suitable.

 

Question 8

An ECS queue processor is stateless, idempotent, and can restart a task after a two-minute interruption notice. It already runs on Fargate. The architecture must reduce Fargate cost for interruption-tolerant tasks. Which option is most cost-effective? Choose ONE.

1. ECS on AWS Fargate
2. Spot Instances
3. Fargate Spot
4. ECS on EC2 with committed pricing

Correct Answer(s)

 

C

Rationale

1. ECS on AWS Fargate charges container tasks for requested compute while removing EC2 host management. It is appropriate when container demand varies and avoiding continuously provisioned hosts is valuable. This scenario prioritizes container task price: the design must reduce Fargate cost for interruption-tolerant tasks. The mismatch makes it less suitable.
2. Spot Instances lower EC2 compute price by accepting reclaimable spare-capacity instances. It is appropriate when the application is designed to survive instance interruption without losing critical state. This scenario prioritizes container task price: the design must reduce Fargate cost for interruption-tolerant tasks. The mismatch makes it less suitable.
3. Fargate Spot runs interruption-tolerant ECS tasks on discounted spare Fargate capacity. Fargate Spot applies discounted spare compute directly to eligible ECS tasks without introducing an EC2 host fleet. It meets the need to reduce Fargate cost for interruption-tolerant tasks and improves container task price.
4. ECS on EC2 with committed pricing runs containers on customer-sized EC2 capacity that can receive EC2 commitment discounts. It is appropriate when container demand is consistently high enough to keep hosts well utilized. This scenario prioritizes container task price: the design must reduce Fargate cost for interruption-tolerant tasks. The mismatch makes it less suitable.

 

Question 9

An EKS cluster runs large nightly ETL pods that are stateless and retry safely. The team wants EKS to manage the worker-node lifecycle. An architect needs to lower Kubernetes node cost by using interruptible managed capacity. What should be selected? Choose ONE.

1. EKS Spot managed node group
2. Fargate Spot
3. ECS on AWS Fargate
4. On-Demand Instances

Correct Answer(s)

 

A

Rationale

1. EKS Spot managed node group runs fault-tolerant Kubernetes pods on EC2 Spot nodes managed by EKS. Managed Spot node groups preserve EKS node lifecycle automation while applying Spot economics to workloads that can be rescheduled. It meets the need to lower Kubernetes node cost by using interruptible managed capacity and improves Kubernetes worker cost.
2. Fargate Spot runs interruption-tolerant ECS tasks on discounted spare Fargate capacity. It is appropriate when container tasks can tolerate a two-minute interruption notice and restart elsewhere. This scenario prioritizes Kubernetes worker cost: the design must lower Kubernetes node cost by using interruptible managed capacity. The mismatch makes it less suitable.
3. ECS on AWS Fargate charges container tasks for requested compute while removing EC2 host management. It is appropriate when container demand varies and avoiding continuously provisioned hosts is valuable. This scenario prioritizes Kubernetes worker cost: the design must lower Kubernetes node cost by using interruptible managed capacity. The mismatch makes it less suitable.
4. On-Demand Instances let teams run EC2 at standard usage rates while retaining freedom to stop or change the workload. It is appropriate when the service is short-lived or its durable baseline has not yet been established. This scenario prioritizes Kubernetes worker cost: the design must lower Kubernetes node cost by using interruptible managed capacity. The mismatch makes it less suitable.

 

Question 10

A research organization has thousands of independent queued simulations. Each job can restart from S3 and the queue can wait for inexpensive capacity. Which change most directly allows the workload to run managed batch compute on discounted interruptible instances? Choose ONE.

1. Spot Instances
2. AWS Lambda pay-per-use compute
3. ECS on AWS Fargate
4. AWS Batch with Spot capacity

Correct Answer(s)

 

D

Rationale

1. Spot Instances use discounted spare EC2 capacity that AWS may reclaim with interruption notice. It is appropriate when workers are fault tolerant and can retry, checkpoint, or redistribute unfinished work. This scenario prioritizes managed batch cost: the design must run managed batch compute on discounted interruptible instances. The mismatch makes it less suitable.
2. AWS Lambda pay-per-use compute runs event-driven code without paying for idle server capacity between invocations. It is appropriate when work arrives intermittently and fits Lambda execution constraints. This scenario prioritizes managed batch cost: the design must run managed batch compute on discounted interruptible instances. The mismatch makes it less suitable.
3. ECS on AWS Fargate charges container tasks for requested compute while removing EC2 host management. It is appropriate when container demand varies and avoiding continuously provisioned hosts is valuable. This scenario prioritizes managed batch cost: the design must run managed batch compute on discounted interruptible instances. The mismatch makes it less suitable.
4. AWS Batch with Spot capacity schedules batch jobs onto managed compute environments that can use Spot. AWS Batch adds job scheduling and managed compute-environment scaling around Spot, matching a deep queue of restartable independent work. It meets the need to run managed batch compute on discounted interruptible instances and improves managed batch cost.

 

Question 11

A thumbnail function runs for a few seconds only when images arrive, with long idle periods between bursts. Which cost-optimization decision best meets the requirement to avoid paying for continuously provisioned servers during idle time? Choose ONE.

1. On-Demand Instances
2. ECS on EC2 with committed pricing
3. AWS Lambda pay-per-use compute
4. Zonal Standard Reserved Instance

Correct Answer(s)

 

C

Rationale

1. On-Demand Instances provide noninterruptible EC2 usage with no one- or three-year spend obligation. It is appropriate when future demand is unclear and purchase flexibility is more valuable than commitment discounts. This scenario prioritizes idle compute spend: the design must avoid paying for continuously provisioned servers during idle time. The mismatch makes it less suitable.
2. ECS on EC2 with committed pricing runs containers on customer-sized EC2 capacity that can receive EC2 commitment discounts. It is appropriate when container demand is consistently high enough to keep hosts well utilized. This scenario prioritizes idle compute spend: the design must avoid paying for continuously provisioned servers during idle time. The mismatch makes it less suitable.
3. AWS Lambda pay-per-use compute runs event-driven code without paying for idle server capacity between invocations. Lambda charges for requests and execution rather than an always-on server fleet, aligning cost with sparse event-driven work. It meets the need to avoid paying for continuously provisioned servers during idle time and improves idle compute spend.
4. Zonal Standard Reserved Instance combines an EC2 billing discount with reserved capacity for matching zonal attributes. It is appropriate when steady EC2 demand also requires capacity assurance in one Availability Zone. This scenario prioritizes idle compute spend: the design must avoid paying for continuously provisioned servers during idle time. The mismatch makes it less suitable.

 

Question 12

A small team runs several container APIs with unpredictable traffic and has no staff to maintain an EC2 container fleet. The architecture must pay for task compute while avoiding idle host and host-management overhead. Which option is most cost-effective? Choose ONE.

1. ECS on EC2 with committed pricing
2. ECS on AWS Fargate
3. AWS Lambda pay-per-use compute
4. EKS Spot managed node group

Correct Answer(s)

 

B

Rationale

1. ECS on EC2 with committed pricing runs containers on customer-sized EC2 capacity that can receive EC2 commitment discounts. It is appropriate when container demand is consistently high enough to keep hosts well utilized. This scenario prioritizes container infrastructure cost: the design must pay for task compute while avoiding idle host and host-management overhead. The mismatch makes it less suitable.
2. ECS on AWS Fargate charges container tasks for requested compute while removing EC2 host management. Fargate removes the requirement to keep EC2 hosts provisioned solely for occasional container demand and eliminates host lifecycle work. It meets the need to pay for task compute while avoiding idle host and host-management overhead and improves container infrastructure cost.
3. AWS Lambda pay-per-use compute runs event-driven code without paying for idle server capacity between invocations. It is appropriate when work arrives intermittently and fits Lambda execution constraints. This scenario prioritizes container infrastructure cost: the design must pay for task compute while avoiding idle host and host-management overhead. The mismatch makes it less suitable.
4. EKS Spot managed node group runs fault-tolerant Kubernetes pods on EC2 Spot nodes managed by EKS. It is appropriate when stateless or batch pods can tolerate node interruption and rescheduling. This scenario prioritizes container infrastructure cost: the design must pay for task compute while avoiding idle host and host-management overhead. The mismatch makes it less suitable.

 

Question 13

A mature ECS platform keeps a large predictable workload above 80 percent host utilization around the clock. The team can manage EC2 hosts and commit to baseline use. An architect needs to use highly utilized committed EC2 capacity for steady containers. What should be selected? Choose ONE.

1. ECS on AWS Fargate
2. Fargate Spot
3. AWS Lambda pay-per-use compute
4. ECS on EC2 with committed pricing

Correct Answer(s)

 

D

Rationale

1. ECS on AWS Fargate charges container tasks for requested compute while removing EC2 host management. It is appropriate when container demand varies and avoiding continuously provisioned hosts is valuable. This scenario prioritizes steady container unit cost: the design must use highly utilized committed EC2 capacity for steady containers. The mismatch makes it less suitable.
2. Fargate Spot runs interruption-tolerant ECS tasks on discounted spare Fargate capacity. It is appropriate when container tasks can tolerate a two-minute interruption notice and restart elsewhere. This scenario prioritizes steady container unit cost: the design must use highly utilized committed EC2 capacity for steady containers. The mismatch makes it less suitable.
3. AWS Lambda pay-per-use compute runs event-driven code without paying for idle server capacity between invocations. It is appropriate when work arrives intermittently and fits Lambda execution constraints. This scenario prioritizes steady container unit cost: the design must use highly utilized committed EC2 capacity for steady containers. The mismatch makes it less suitable.
4. ECS on EC2 with committed pricing runs containers on customer-sized EC2 capacity that can receive EC2 commitment discounts. Consistently high host utilization makes EC2 capacity efficient, while a commitment can lower the rate for the durable baseline. It meets the need to use highly utilized committed EC2 capacity for steady containers and improves steady container unit cost.

 

Question 14

A stateless Linux web tier compiles cleanly for Arm and performance tests show equal throughput on Graviton and x86 instances. Which change most directly allows the workload to reduce EC2 cost per request without changing service behavior? Choose ONE.

1. Graviton-based EC2 instances
2. EC2 Instance Savings Plans
3. Right-size EC2 instance size
4. Spot Instances

Correct Answer(s)

 

A

Rationale

1. Graviton-based EC2 instances use Arm-based AWS processors with strong price performance for compatible workloads. When software is Arm-compatible and throughput is comparable, Graviton price performance can reduce the infrastructure cost for the same useful work. It meets the need to reduce EC2 cost per request without changing service behavior and improves cost per request.
2. EC2 Instance Savings Plans discount usage within one EC2 instance family in a selected Region. It is appropriate when steady EC2 use stays in one family and Region while size may change. This scenario prioritizes cost per request: the design must reduce EC2 cost per request without changing service behavior. The mismatch makes it less suitable.
3. Right-size EC2 instance size aligns an EC2 instance type or size with observed workload requirements instead of historical guesses. It is appropriate when monitoring demonstrates that the current shape is consistently over- or under-provisioned. This scenario prioritizes cost per request: the design must reduce EC2 cost per request without changing service behavior. The mismatch makes it less suitable.
4. Spot Instances lower EC2 compute price by accepting reclaimable spare-capacity instances. It is appropriate when the application is designed to survive instance interruption without losing critical state. This scenario prioritizes cost per request: the design must reduce EC2 cost per request without changing service behavior. The mismatch makes it less suitable.

 

Question 15

A Lambda function and all native dependencies support arm64. Load tests show equivalent latency and memory use on both architectures. Which cost-optimization decision best meets the requirement to lower Lambda compute price without changing application semantics? Choose ONE.

1. AWS Compute Optimizer Lambda recommendations
2. Lambda arm64 architecture
3. Compute Savings Plans
4. AWS Lambda pay-per-use compute

Correct Answer(s)

 

B

Rationale

1. AWS Compute Optimizer Lambda recommendations recommends Lambda memory settings from observed function performance and cost data. It is appropriate when supported Lambda functions have enough invocation history for memory optimization. This scenario prioritizes function compute cost: the design must lower Lambda compute price without changing application semantics. The mismatch makes it less suitable.
2. Lambda arm64 architecture runs compatible Lambda functions on Arm-based Graviton processors at lower compute pricing. Using the Arm architecture can reduce Lambda duration pricing for compatible code while preserving the serverless operating model. It meets the need to lower Lambda compute price without changing application semantics and improves function compute cost.
3. Compute Savings Plans trade an hourly usage commitment for broad compute discounts spanning EC2, Fargate, and Lambda. It is appropriate when long-lived compute has a stable floor but workload placement can change. This scenario prioritizes function compute cost: the design must lower Lambda compute price without changing application semantics. The mismatch makes it less suitable.
4. AWS Lambda pay-per-use compute runs event-driven code without paying for idle server capacity between invocations. It is appropriate when work arrives intermittently and fits Lambda execution constraints. This scenario prioritizes function compute cost: the design must lower Lambda compute price without changing application semantics. The mismatch makes it less suitable.

 

Question 16

A company wants to purchase Savings Plans but usage has a steady $40-per-hour floor and irregular peaks up to $90 per hour. The architecture must avoid paying a commitment for usage that appears only during uncertain peaks. Which option is most cost-effective? Choose ONE.

1. Compute Savings Plans
2. Cost Explorer Savings Plans recommendations
3. Savings Plans commitment based on steady baseline
4. On-Demand Instances

Correct Answer(s)

 

C

Rationale

1. Compute Savings Plans reduce eligible EC2, Fargate, and Lambda charges through a flexible hourly spend commitment. It is appropriate when baseline compute spend is predictable while the exact service, family, or Region can vary. This scenario prioritizes commitment utilization: the design must avoid paying a commitment for usage that appears only during uncertain peaks. The mismatch makes it less suitable.
2. Cost Explorer Savings Plans recommendations estimates commitment levels from eligible historical compute usage and preferences. It is appropriate when an organization wants data-driven Savings Plans purchase guidance. This scenario prioritizes commitment utilization: the design must avoid paying a commitment for usage that appears only during uncertain peaks. The mismatch makes it less suitable.
3. Savings Plans commitment based on steady baseline commits only the durable hourly usage floor while variable demand remains On-Demand. A commitment aligned to the repeatable floor has high utilization; committing to sporadic peaks risks paying for unused Savings Plan capacity. It meets the need to avoid paying a commitment for usage that appears only during uncertain peaks and improves commitment utilization.
4. On-Demand Instances bill EC2 capacity as it is consumed without requiring a multi-year pricing commitment. It is appropriate when the workload is temporary, uncertain, or cannot accept Spot interruption. This scenario prioritizes commitment utilization: the design must avoid paying a commitment for usage that appears only during uncertain peaks. The mismatch makes it less suitable.

 

Question 17

Finance needs a defensible starting point for a new Savings Plans purchase based on historical eligible compute usage, term, and payment preference. An architect needs to generate data-driven Savings Plans commitment guidance. What should be selected? Choose ONE.

1. AWS Cost and Usage Report
2. Cost Explorer Savings Plans recommendations
3. AWS Budgets
4. Cost allocation tags

Correct Answer(s)

 

B

Rationale

1. AWS Cost and Usage Report exports detailed billing and usage line items for granular cost analysis. It is appropriate when teams need raw resource-level charge data for custom analysis or allocation. This scenario prioritizes purchase planning quality: the design must generate data-driven Savings Plans commitment guidance. The mismatch makes it less suitable.
2. Cost Explorer Savings Plans recommendations estimates commitment levels from eligible historical compute usage and preferences. Cost Explorer analyzes eligible historical usage and produces commitment recommendations, which directly supports purchase sizing rather than only reporting raw charges. It meets the need to generate data-driven Savings Plans commitment guidance and improves purchase planning quality.
3. AWS Budgets tracks cost or usage against thresholds and can notify or invoke budget actions. It is appropriate when owners need proactive warning when spending approaches an agreed limit. This scenario prioritizes purchase planning quality: the design must generate data-driven Savings Plans commitment guidance. The mismatch makes it less suitable.
4. Cost allocation tags label resources so activated tag values can be grouped in cost reporting. It is appropriate when shared billing must be attributed to teams applications or environments. This scenario prioritizes purchase planning quality: the design must generate data-driven Savings Plans commitment guidance. The mismatch makes it less suitable.

 

Question 18

A service reserved EC2 capacity for a product launch. The launch is over, no instances use the reservation, and the business no longer needs capacity assurance. Which change most directly allows the workload to stop ongoing charges for idle reserved capacity? Choose ONE.

1. On-Demand Capacity Reservation plus Savings Plan
2. Savings Plans commitment based on steady baseline
3. Cancel unused Capacity Reservation
4. Right-size EC2 instance size

Correct Answer(s)

 

C

Rationale

1. On-Demand Capacity Reservation plus Savings Plan pairs zonal capacity assurance with a separate eligible usage discount. It is appropriate when exact zonal capacity must be held while long-term compute usage also merits a discount. This scenario prioritizes idle reservation cost: the design must stop ongoing charges for idle reserved capacity. The mismatch makes it less suitable.
2. Savings Plans commitment based on steady baseline commits only the durable hourly usage floor while variable demand remains On-Demand. It is appropriate when usage has a stable minimum plus uncertain peaks that should not be overcommitted. This scenario prioritizes idle reservation cost: the design must stop ongoing charges for idle reserved capacity. The mismatch makes it less suitable.
3. Cancel unused Capacity Reservation stops paying for idle reserved EC2 capacity that is no longer required. Unused Capacity Reservations can still generate charges, so removing an unnecessary reservation eliminates cost without affecting running workload capacity. It meets the need to stop ongoing charges for idle reserved capacity and improves idle reservation cost.
4. Right-size EC2 instance size adjusts provisioned EC2 resources to the capacity the workload actually consumes. It is appropriate when reliable metrics show a sustained mismatch between allocated and needed resources. This scenario prioritizes idle reservation cost: the design must stop ongoing charges for idle reserved capacity. The mismatch makes it less suitable.

 

Question 19

A payment service needs guaranteed capacity for a specific instance type in one Availability Zone, and its steady usage also justifies a one-year commitment discount. Which cost-optimization decision best meets the requirement to obtain zonal capacity assurance while separately reducing eligible usage price? Choose ONE.

1. Zonal Standard Reserved Instance
2. Compute Savings Plans
3. EC2 Instance Savings Plans
4. On-Demand Capacity Reservation plus Savings Plan

Correct Answer(s)

 

D

Rationale

1. Zonal Standard Reserved Instance combines an EC2 billing discount with reserved capacity for matching zonal attributes. It is appropriate when steady EC2 demand also requires capacity assurance in one Availability Zone. This scenario prioritizes capacity-assured effective rate: the design must obtain zonal capacity assurance while separately reducing eligible usage price. The mismatch makes it less suitable.
2. Compute Savings Plans reduce eligible EC2, Fargate, and Lambda charges through a flexible hourly spend commitment. It is appropriate when baseline compute spend is predictable while the exact service, family, or Region can vary. This scenario prioritizes capacity-assured effective rate: the design must obtain zonal capacity assurance while separately reducing eligible usage price. The mismatch makes it less suitable.
3. EC2 Instance Savings Plans discount usage within one EC2 instance family in a selected Region. It is appropriate when steady EC2 use stays in one family and Region while size may change. This scenario prioritizes capacity-assured effective rate: the design must obtain zonal capacity assurance while separately reducing eligible usage price. The mismatch makes it less suitable.
4. On-Demand Capacity Reservation plus Savings Plan pairs zonal capacity assurance with a separate eligible usage discount. Capacity Reservations address launch assurance while Savings Plans address eligible usage price, allowing the architecture to satisfy both requirements independently. It meets the need to obtain zonal capacity assurance while separately reducing eligible usage price and improves capacity-assured effective rate.

 

Question 20

Three linked accounts have complementary EC2 and Fargate usage. One account owns a Savings Plan that is underused while another pays On-Demand rates for eligible usage. The architecture must apply unused commitment benefits across eligible organization usage where policy allows. Which option is most cost-effective? Choose ONE.

1. Savings Plans sharing in consolidated billing
2. Cost allocation tags
3. AWS Cost and Usage Report
4. Compute Savings Plans

Correct Answer(s)

 

A

Rationale

1. Savings Plans sharing in consolidated billing allows eligible organization accounts to benefit from unused Savings Plans coverage. Sharing lets eligible usage in linked accounts consume otherwise unused Savings Plan coverage, increasing commitment utilization without buying a second plan. It meets the need to apply unused commitment benefits across eligible organization usage where policy allows and improves organization commitment utilization.
2. Cost allocation tags label resources so activated tag values can be grouped in cost reporting. It is appropriate when shared billing must be attributed to teams applications or environments. This scenario prioritizes organization commitment utilization: the design must apply unused commitment benefits across eligible organization usage where policy allows. The mismatch makes it less suitable.
3. AWS Cost and Usage Report exports detailed billing and usage line items for granular cost analysis. It is appropriate when teams need raw resource-level charge data for custom analysis or allocation. This scenario prioritizes organization commitment utilization: the design must apply unused commitment benefits across eligible organization usage where policy allows. The mismatch makes it less suitable.
4. Compute Savings Plans apply a committed-rate discount across qualifying EC2 usage and eligible serverless or container compute. It is appropriate when the organization wants one commitment to follow changing compute choices. This scenario prioritizes organization commitment utilization: the design must apply unused commitment benefits across eligible organization usage where policy allows. The mismatch makes it less suitable.

• < Amazon AWS SAA-C03 Cost-Optimized Storage, Tiering, Lifecycle, Backup, Archive, and Transfer Practice Test 3
• Amazon AWS SAA-C03 Cost-Optimized Compute, Purchasing Models, Rightsizing, and Elasticity Practice Test 2 >