Amazon AWS SAA-C03 Cost-Optimized Compute, Purchasing Models, Rightsizing, and Elasticity Practice Test 3

 

Topic 18 Practice Test 3 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 team bought an EC2 Instance Savings Plan expecting it to discount Lambda and Fargate after an upcoming migration. The migration is now confirmed. Which cost-optimization decision best meets the requirement to use a commitment type that continues to cover eligible EC2 Fargate and Lambda usage? Choose ONE.

1. Compute Savings Plans
2. EC2 Instance Savings Plans
3. On-Demand Instances
4. Savings Plans sharing in consolidated billing

Correct Answer(s)

 

A

Rationale

1. Compute Savings Plans apply a committed-rate discount across qualifying EC2 usage and eligible serverless or container compute. Compute Savings Plans cover eligible EC2 usage plus Fargate and Lambda, so they match a migration that crosses compute services rather than remaining in one EC2 family. It meets the need to use a commitment type that continues to cover eligible EC2 Fargate and Lambda usage and improves post-migration discount coverage.
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 post-migration discount coverage: the design must use a commitment type that continues to cover eligible EC2 Fargate and Lambda usage. 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 post-migration discount coverage: the design must use a commitment type that continues to cover eligible EC2 Fargate and Lambda usage. The mismatch makes it less suitable.
4. Savings Plans sharing in consolidated billing allows eligible organization accounts to benefit from unused Savings Plans coverage. It is appropriate when multiple linked accounts have complementary eligible compute usage patterns. This scenario prioritizes post-migration discount coverage: the design must use a commitment type that continues to cover eligible EC2 Fargate and Lambda usage. The mismatch makes it less suitable.

 

Question 2

A workload stays in the M family in one Region, runs continuously, and will not move to Lambda or Fargate. Finance wants the strongest Savings Plans discount compatible with those constraints. The architecture must commit to the stable family and Region rather than pay for unnecessary cross-service flexibility. Which option is most cost-effective? Choose ONE.

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

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 family-specific committed rate: the design must commit to the stable family and Region rather than pay for unnecessary cross-service flexibility. The mismatch makes it less suitable.
2. 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 family-specific committed rate: the design must commit to the stable family and Region rather than pay for unnecessary cross-service flexibility. The mismatch makes it less suitable.
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 family-specific committed rate: the design must commit to the stable family and Region rather than pay for unnecessary cross-service flexibility. The mismatch makes it less suitable.
4. EC2 Instance Savings Plans discount usage within one EC2 instance family in a selected Region. The workload does not need Compute Savings Plan flexibility, so the family-and-Region commitment can provide a more targeted discount for the known usage. It meets the need to commit to the stable family and Region rather than pay for unnecessary cross-service flexibility and improves family-specific committed rate.

 

Question 3

A data pipeline runs entirely on On-Demand instances even though every stage can retry from durable checkpoints and completion time is flexible. An architect needs to replace nonessential guaranteed capacity with discounted interruptible compute. What should be selected? Choose ONE.

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

Correct Answer(s)

 

B

Rationale

1. 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 pipeline compute cost: the design must replace nonessential guaranteed capacity with discounted interruptible compute. The mismatch makes it less suitable.
2. Spot Instances use discounted spare EC2 capacity that AWS may reclaim with interruption notice. Retryable checkpointed work has the failure tolerance needed for Spot, so paying On-Demand rates for all workers is unnecessary. It meets the need to replace nonessential guaranteed capacity with discounted interruptible compute and improves pipeline compute cost.
3. 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 pipeline compute cost: the design must replace nonessential guaranteed capacity with discounted interruptible compute. The mismatch makes it less suitable.
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 pipeline compute cost: the design must replace nonessential guaranteed capacity with discounted interruptible compute. The mismatch makes it less suitable.

 

Question 4

A Spot Auto Scaling group uses the lowest-price strategy and repeatedly loses large portions of capacity. Reprocessing cost now exceeds the small price difference between pools. Which change most directly allows the workload to choose Spot pools using a price-and-capacity tradeoff to reduce costly interruptions? Choose ONE.

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

Correct Answer(s)

 

C

Rationale

1. 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 cost after interruption rework: the design must choose Spot pools using a price-and-capacity tradeoff to reduce costly interruptions. The mismatch makes it less suitable.
2. Mixed On-Demand and Spot Auto Scaling combines a stable On-Demand base with discounted Spot capacity above it. It is appropriate when a service needs noninterruptible baseline capacity and interruptible elastic workers. This scenario prioritizes cost after interruption rework: the design must choose Spot pools using a price-and-capacity tradeoff to reduce costly interruptions. The mismatch makes it less suitable.
3. Price-capacity-optimized Spot allocation balances Spot price with pool capacity to reduce interruption exposure. The problem is selecting pools solely by price; price-capacity-optimized incorporates capacity depth and price so avoided rework contributes to lower effective cost. It meets the need to choose Spot pools using a price-and-capacity tradeoff to reduce costly interruptions and improves cost after interruption rework.
4. 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 cost after interruption rework: the design must choose Spot pools using a price-and-capacity tradeoff to reduce costly interruptions. The mismatch makes it less suitable.

 

Question 5

An ECS batch service runs on standard Fargate. Every task is idempotent, jobs are queued durably, and tasks can restart after an interruption. Which cost-optimization decision best meets the requirement to use discounted Fargate capacity for retryable tasks? Choose ONE.

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

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 Fargate batch cost: the design must use discounted Fargate capacity for retryable tasks. 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 Fargate batch cost: the design must use discounted Fargate capacity for retryable tasks. The mismatch makes it less suitable.
3. 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 Fargate batch cost: the design must use discounted Fargate capacity for retryable tasks. The mismatch makes it less suitable.
4. Fargate Spot runs interruption-tolerant ECS tasks on discounted spare Fargate capacity. Fargate Spot preserves the serverless container model while lowering the rate for tasks that can tolerate interruption and restart. It meets the need to use discounted Fargate capacity for retryable tasks and improves Fargate batch cost.

 

Question 6

An EKS team uses only On-Demand managed nodes for a stateless processing namespace. Pods have disruption budgets and retry safely elsewhere. The architecture must reduce node price for the fault-tolerant Kubernetes workload. Which option is most cost-effective? Choose ONE.

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

Correct Answer(s)

 

B

Rationale

1. 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 EKS worker price: the design must reduce node price for the fault-tolerant Kubernetes workload. The mismatch makes it less suitable.
2. EKS Spot managed node group runs fault-tolerant Kubernetes pods on EC2 Spot nodes managed by EKS. Spot managed nodes apply discounted EC2 capacity while EKS continues node lifecycle management, fitting pods that can reschedule after interruption. It meets the need to reduce node price for the fault-tolerant Kubernetes workload and improves EKS worker price.
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 EKS worker price: the design must reduce node price for the fault-tolerant Kubernetes workload. The mismatch makes it less suitable.
4. 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 EKS worker price: the design must reduce node price for the fault-tolerant Kubernetes workload. The mismatch makes it less suitable.

 

Question 7

Twenty developer EC2 instances remain running all night and weekend, but developers need the same EBS volumes and host identities each workday. An architect needs to stop paying compute charges during predictable idle periods without deleting the servers. What should be selected? Choose ONE.

1. EC2 instance scheduling automation
2. Scheduled Auto Scaling to zero
3. Spot Instances
4. Right-size EC2 instance size

Correct Answer(s)

 

A

Rationale

1. EC2 instance scheduling automation stops and starts EBS-backed EC2 instances according to a known business schedule. Scheduling stop and start preserves persistent instance storage while eliminating most off-hours compute charges for machines that do not need continuous availability. It meets the need to stop paying compute charges during predictable idle periods without deleting the servers and improves developer idle cost.
2. Scheduled Auto Scaling to zero sets nonproduction group capacity to zero during known idle periods. It is appropriate when a stateless environment is unnecessary outside a predictable schedule. This scenario prioritizes developer idle cost: the design must stop paying compute charges during predictable idle periods without deleting the servers. The mismatch makes it less suitable.
3. 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 developer idle cost: the design must stop paying compute charges during predictable idle periods without deleting the servers. The mismatch makes it less suitable.
4. 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 developer idle cost: the design must stop paying compute charges during predictable idle periods without deleting the servers. The mismatch makes it less suitable.

 

Question 8

A production EC2 instance has averaged 8 percent CPU and 30 percent memory for two months. Performance tests confirm a smaller size has ample headroom. Which change most directly allows the workload to remove recurring cost caused by an oversized instance? Choose ONE.

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

Correct Answer(s)

 

C

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 resource utilization efficiency: the design must remove recurring cost caused by an oversized instance. The mismatch makes it less suitable.
2. 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 resource utilization efficiency: the design must remove recurring cost caused by an oversized instance. The mismatch makes it less suitable.
3. Right-size EC2 instance size adjusts provisioned EC2 resources to the capacity the workload actually consumes. The utilization data and test results show excess capacity, so rightsizing reduces the underlying resource cost rather than only discounting the oversized shape. It meets the need to remove recurring cost caused by an oversized instance and improves resource utilization efficiency.
4. Graviton-based EC2 instances use Arm-based AWS processors with strong price performance for compatible workloads. It is appropriate when software and dependencies support Arm and cost per unit of work matters. This scenario prioritizes resource utilization efficiency: the design must remove recurring cost caused by an oversized instance. The mismatch makes it less suitable.

 

Question 9

A Lambda function has enough history for Compute Optimizer and shows high duration cost. The team wants a recommended memory setting before running new load tests. Which cost-optimization decision best meets the requirement to use observed function data to identify a better memory and cost point? Choose ONE.

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

Correct Answer(s)

 

B

Rationale

1. Lambda arm64 architecture runs compatible Lambda functions on Arm-based Graviton processors at lower compute pricing. It is appropriate when function code and dependencies support arm64 without emulation. This scenario prioritizes function cost efficiency: the design must use observed function data to identify a better memory and cost point. The mismatch makes it less suitable.
2. AWS Compute Optimizer Lambda recommendations recommends Lambda memory settings from observed function performance and cost data. Compute Optimizer is designed to use historical Lambda metrics for memory sizing recommendations, giving the team an evidence-based candidate configuration to test. It meets the need to use observed function data to identify a better memory and cost point and improves function cost efficiency.
3. 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 function cost efficiency: the design must use observed function data to identify a better memory and cost point. 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 cost efficiency: the design must use observed function data to identify a better memory and cost point. The mismatch makes it less suitable.

 

Question 10

A nightly transformation still runs on an EC2 instance that remains idle for 23 hours after the job. The code can run as a short event-triggered function. The architecture must eliminate server idle time by using execution-based billing. Which option is most cost-effective? Choose ONE.

1. AWS Lambda pay-per-use compute
2. Scheduled stop and start for nonproduction EC2
3. On-Demand Instances
4. ECS on EC2 with committed pricing

Correct Answer(s)

 

A

Rationale

1. AWS Lambda pay-per-use compute runs event-driven code without paying for idle server capacity between invocations. The serverless model bills the brief execution instead of a persistent instance, directly removing the dominant idle-compute portion of the cost. It meets the need to eliminate server idle time by using execution-based billing and improves daily idle spend.
2. Scheduled stop and start for nonproduction EC2 removes EC2 compute charges while stopped outside known working hours. It is appropriate when EBS-backed development servers are idle on a predictable schedule and may be offline. This scenario prioritizes daily idle spend: the design must eliminate server idle time by using execution-based billing. 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 daily idle spend: the design must eliminate server idle time by using execution-based billing. 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. It is appropriate when container demand is consistently high enough to keep hosts well utilized. This scenario prioritizes daily idle spend: the design must eliminate server idle time by using execution-based billing. The mismatch makes it less suitable.

 

Question 11

An x86 service has no architecture-specific dependencies. Graviton testing meets latency targets and processes the same request volume at a lower hourly cost. An architect needs to adopt the instance architecture with better validated price performance. What should be selected? Choose ONE.

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

Correct Answer(s)

 

C

Rationale

1. 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 price performance: the design must adopt the instance architecture with better validated price performance. 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 price performance: the design must adopt the instance architecture with better validated price performance. The mismatch makes it less suitable.
3. Graviton-based EC2 instances use Arm-based AWS processors with strong price performance for compatible workloads. The workload has proven Arm compatibility and equivalent service performance, so Graviton lowers infrastructure cost per unit of useful traffic. It meets the need to adopt the instance architecture with better validated price performance and improves price performance.
4. 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 price performance: the design must adopt the instance architecture with better validated price performance. The mismatch makes it less suitable.

 

Question 12

A payer has a Compute Savings Plan sized to its historical minimum, but a new account is excluded from discount sharing and pays On-Demand for eligible EC2 usage. Which change most directly allows the workload to let eligible linked-account usage consume available commitment coverage? Choose ONE.

1. Compute Savings Plans
2. Cost allocation tags
3. Cost Explorer Savings Plans recommendations
4. Savings Plans sharing in consolidated billing

Correct Answer(s)

 

D

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 existing commitment utilization: the design must let eligible linked-account usage consume available commitment coverage. The mismatch makes it less suitable.
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 existing commitment utilization: the design must let eligible linked-account usage consume available commitment coverage. The mismatch makes it less suitable.
3. 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 existing commitment utilization: the design must let eligible linked-account usage consume available commitment coverage. The mismatch makes it less suitable.
4. Savings Plans sharing in consolidated billing allows eligible organization accounts to benefit from unused Savings Plans coverage. The commitment already exists and has unused coverage, so sharing addresses the allocation problem without purchasing more committed spend. It meets the need to let eligible linked-account usage consume available commitment coverage and improves existing commitment utilization.

 

Question 13

A company bought a large Savings Plan based on a one-week peak and now leaves much of the hourly commitment unused most days. Which cost-optimization decision best meets the requirement to avoid repeating overcommitment when the current plan expires? Choose ONE.

1. Cost Explorer Savings Plans recommendations
2. Compute Savings Plans
3. Savings Plans commitment based on steady baseline
4. AWS Budgets

Correct Answer(s)

 

C

Rationale

1. 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 future commitment utilization: the design must avoid repeating overcommitment when the current plan expires. The mismatch makes it less suitable.
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 future commitment utilization: the design must avoid repeating overcommitment when the current plan expires. 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. Savings Plans are paid commitments, so a stable baseline is the safer coverage target when peaks are not consistently present. It meets the need to avoid repeating overcommitment when the current plan expires and improves future commitment utilization.
4. 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 future commitment utilization: the design must avoid repeating overcommitment when the current plan expires. The mismatch makes it less suitable.

 

Question 14

A new product may be cancelled after two months and traffic could vary by an order of magnitude. The workload cannot tolerate Spot interruptions. The architecture must preserve pricing flexibility until the workload pattern becomes durable. Which option is most cost-effective? Choose ONE.

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

Correct Answer(s)

 

B

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 risk: the design must preserve pricing flexibility until the workload pattern becomes durable. The mismatch makes it less suitable.
2. On-Demand Instances let teams run EC2 at standard usage rates while retaining freedom to stop or change the workload. On-Demand avoids locking the organization into a one- or three-year commitment while the product lifetime and steady usage remain unknown. It meets the need to preserve pricing flexibility until the workload pattern becomes durable and improves commitment risk.
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 commitment risk: the design must preserve pricing flexibility until the workload pattern becomes durable. The mismatch makes it less suitable.
4. 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 commitment risk: the design must preserve pricing flexibility until the workload pattern becomes durable. The mismatch makes it less suitable.

 

Question 15

A critical service requires ten matching instances in one Availability Zone during quarterly events. The company also has steady eligible EC2 spend covered by a Savings Plan. An architect needs to ensure the exact zonal capacity is available without giving up the separate usage discount. What should be selected? Choose ONE.

1. Zonal Standard Reserved Instance
2. EC2 Instance Savings Plans
3. On-Demand Instances
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 and price independence: the design must ensure the exact zonal capacity is available without giving up the separate usage discount. 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 capacity and price independence: the design must ensure the exact zonal capacity is available without giving up the separate usage discount. 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 capacity and price independence: the design must ensure the exact zonal capacity is available without giving up the separate usage discount. 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 and Savings Plans solve different constraints: one secures zonal capacity and the other reduces eligible compute price. It meets the need to ensure the exact zonal capacity is available without giving up the separate usage discount and improves capacity and price independence.

 

Question 16

A Capacity Reservation created for a cancelled launch shows zero instance utilization but continues appearing as an unused reservation charge. Which change most directly allows the workload to eliminate the unused reservation cost because capacity assurance is no longer required? Choose ONE.

1. Cancel unused Capacity Reservation
2. On-Demand Capacity Reservation plus Savings Plan
3. On-Demand Instances
4. Right-size EC2 instance size

Correct Answer(s)

 

A

Rationale

1. Cancel unused Capacity Reservation stops paying for idle reserved EC2 capacity that is no longer required. No workload needs the reserved capacity, so retaining it provides no operational value while unused capacity can continue generating cost. It meets the need to eliminate the unused reservation cost because capacity assurance is no longer required and improves reservation waste.
2. 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 reservation waste: the design must eliminate the unused reservation cost because capacity assurance is no longer required. 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 reservation waste: the design must eliminate the unused reservation cost because capacity assurance is no longer required. The mismatch makes it less suitable.
4. 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 reservation waste: the design must eliminate the unused reservation cost because capacity assurance is no longer required. The mismatch makes it less suitable.

 

Question 17

A Fargate web task mostly waits for occasional events and can be rewritten as a short stateless handler within Lambda limits. Which cost-optimization decision best meets the requirement to remove billed idle container time for a sparse event-driven workload? Choose ONE.

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

Correct Answer(s)

 

B

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 idle service cost: the design must remove billed idle container time for a sparse event-driven workload. 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. Lambda aligns charges with the brief event executions, whereas a continuously running Fargate task keeps accruing task compute charges while waiting. It meets the need to remove billed idle container time for a sparse event-driven workload and improves idle service cost.
3. 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 idle service cost: the design must remove billed idle container time for a sparse event-driven workload. 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. It is appropriate when container demand is consistently high enough to keep hosts well utilized. This scenario prioritizes idle service cost: the design must remove billed idle container time for a sparse event-driven workload. The mismatch makes it less suitable.

 

Question 18

Finance sees a large compute charge but needs resource IDs, usage types, discount fields, and hourly line items to trace it precisely. The architecture must obtain detailed billing records suitable for custom root-cause analysis. Which option is most cost-effective? Choose ONE.

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

Correct Answer(s)

 

D

Rationale

1. 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 cost investigation detail: the design must obtain detailed billing records suitable for custom root-cause analysis. The mismatch makes it less suitable.
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 cost investigation detail: the design must obtain detailed billing records suitable for custom root-cause analysis. The mismatch makes it less suitable.
3. 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 cost investigation detail: the design must obtain detailed billing records suitable for custom root-cause analysis. The mismatch makes it less suitable.
4. AWS Cost and Usage Report exports detailed billing and usage line items for granular cost analysis. The report contains granular usage and charge records needed to trace a cost anomaly; an alert or tag alone does not provide that raw detail. It meets the need to obtain detailed billing records suitable for custom root-cause analysis and improves cost investigation detail.

 

Question 19

Engineering has accurate cost reports but cannot tell which of five teams owns many EC2 and Fargate resources. The teams agree to enforce a standard ownership label. An architect needs to make future compute charges groupable by team ownership. What should be selected? Choose ONE.

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

Correct Answer(s)

 

A

Rationale

1. Cost allocation tags label resources so activated tag values can be grouped in cost reporting. Once activated, the tag becomes a billing dimension for grouping charges, resolving attribution rather than merely exporting the same unclassified data. It meets the need to make future compute charges groupable by team ownership and improves team chargeback accuracy.
2. 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 team chargeback accuracy: the design must make future compute charges groupable by team ownership. The mismatch makes it less suitable.
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 team chargeback accuracy: the design must make future compute charges groupable by team ownership. The mismatch makes it less suitable.
4. Savings Plans sharing in consolidated billing allows eligible organization accounts to benefit from unused Savings Plans coverage. It is appropriate when multiple linked accounts have complementary eligible compute usage patterns. This scenario prioritizes team chargeback accuracy: the design must make future compute charges groupable by team ownership. The mismatch makes it less suitable.

 

Question 20

A business unit wants email alerts at 80 percent and 100 percent of its monthly AWS cost target so managers can respond before overspending. Which change most directly allows the workload to track actual and forecast spend against a defined financial threshold? Choose ONE.

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

Correct Answer(s)

 

C

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 budget threshold awareness: the design must track actual and forecast spend against a defined financial threshold. The mismatch makes it less suitable.
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 budget threshold awareness: the design must track actual and forecast spend against a defined financial threshold. The mismatch makes it less suitable.
3. AWS Budgets tracks cost or usage against thresholds and can notify or invoke budget actions. AWS Budgets is built to compare cost or usage with defined limits and notify stakeholders, which directly supports proactive spend governance. It meets the need to track actual and forecast spend against a defined financial threshold and improves budget threshold awareness.
4. 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 budget threshold awareness: the design must track actual and forecast spend against a defined financial threshold. The mismatch makes it less suitable.

• < Amazon AWS SAA-C03 Cost-Optimized Compute, Purchasing Models, Rightsizing, and Elasticity Practice Test 2
• Amazon AWS SAA-C03 Cost-Optimized Databases, Capacity, Serverless, Caching, Retention, and Migration Practice Test 1 >