AWS Certified Solutions Architect - Associate SAA-C03 Practice Test 89
Question 880
A production web tier runs one EC2 family in one Region at near-full baseline utilization year-round. The organization accepts a one- or three-year spend commitment for a larger discount and is confident in that family/region. Which pricing instrument merits comparison?
- Use On-Demand alone because long, predictable usage never benefits from discounted commitments.
- Use a Compute Savings Plan only because it is always strictly more discounted than a narrower Instance Savings Plan.
- Purchase Spot for all noninterruptible baseline capacity with no fallback as if interruption were impossible.
- Evaluate an EC2 Instance Savings Plan matching the eligible family/Region usage and term.
Explanation
Correct Answer
D:Instance Savings Plans exchange narrower usage flexibility for a potentially higher discount when the workload shape is stable.
Incorrect Answers
A:Predictable eligible usage can justify a commitment after financial modeling.
B:Compute plans generally offer broader flexibility, with different discount tradeoffs.
C:Spot capacity is reclaimable and may not meet continuous critical service obligations alone.
Question 881
A company buys a Compute Savings Plan and tells operations it has reserved a specific rack of EC2 capacity during regional shortages. What must be clarified?
- A Savings Plan is a billing commitment, not a guarantee of physical EC2 capacity; evaluate supported reservations separately if needed.
- Treat a Savings Plan as identical to an On-Demand Capacity Reservation for any family and AZ.
- Assume all Savings Plans constrain instances to one exact rack and prevent Auto Scaling.
- Increase a Compute Savings Plan’s commitment amount and assume the larger discount purchase also guarantees physical instance inventory in the chosen AZ.
Explanation
Correct Answer
A:A discounted usage rate does not automatically assure the chosen instances can launch during a capacity shortage.
Incorrect Answers
B:The financial discount does not create equivalent reserved hardware capacity.
C:Savings Plan usage matching and capacity placement are separate concerns.
D:Savings Plan dollar commitments affect covered compute billing, not available EC2 physical capacity. Capacity Reservations or appropriately configured other offerings must be evaluated separately when capacity assurance is required.
Question 882
An EC2 Auto Scaling group runs stateless container workers. The workers can restart after Spot interruption, and an On-Demand base already handles critical capacity. The existing Spot configuration picks only the lowest-price pool and suffers frequent interruptions. Which strategy balances Spot savings with availability?
- Set lowest-price allocation to a single instance family and one Availability Zone to avoid switching pools.
- Use a mixed-instances Auto Scaling group with several compatible families and Availability Zones and the price-capacity-optimized Spot allocation strategy.
- Replace Spot workers with RDS Reserved Instances because an RDS reservation discounts EC2 Spot capacity directly.
- Disable health replacement for interrupted Spot instances to make the Spot price more predictable.
Explanation
Correct Answer
B:Price-capacity-optimized evaluates both price and capacity and is recommended for Auto Scaling Spot pools; diversity gives the group more viable capacity choices.
Incorrect Answers
A:Concentrating requests in cheap but scarce pools increases interruption/availability risk rather than considering pool capacity.
C:RDS Reserved Instances apply to eligible database usage, not the price of EC2 Spot container workers.
D:Stopping instance replacement leaves capacity short after interruptions and does not lower the price of surviving instances.
Question 883
A software company expects an EC2 fleet to move across instance families after a platform rewrite. Finance compares Standard and Convertible Reserved Instances solely by the largest advertised discount. Which tradeoff matters?
- Assume Standard and Convertible RIs always have identical exchange flexibility and discount levels.
- Use only a current one-day peak to forecast a three-year commitment while ignoring planned family changes.
- Model Standard RI discount versus its more restrictive modification options, and Convertible RI flexibility for changing eligible instance attributes.
- Expect an RI to automatically perform the application's code migration when its family changes.
Explanation
Correct Answer
C:Commitment value depends on how likely workload family changes will strand a less-flexible reservation.
Incorrect Answers
A:Standard and Convertible Reserved Instances have different commitment flexibility and discount characteristics. Treating their exchange rights and effective rates as identical can produce an inaccurate reservation strategy for changing workloads.
B:A peak snapshot is insufficient for long-term reservation coverage.
D:Billing commitments do not port software binaries or remove architecture incompatibilities.
Question 884
An EC2 fleet requires a particular instance class in one AZ even during a capacity crunch. The company proposes regional RIs solely for their discount and treats that as AZ capacity assurance. What distinction matters?
- Assume regional RIs guarantee any requested EC2 launch in every AZ at any scale.
- Use only a Savings Plan and consider its monthly payment proof of exact host reservation.
- Increase the EBS root volume size to convert a regional RI into a zonal capacity reservation.
- Separate a regional pricing commitment from a zonal RI or On-Demand Capacity Reservation that provides applicable AZ capacity reservation behavior.
Explanation
Correct Answer
D:Discount scope and guaranteed capacity placement are different terms; the latter requires an appropriate reservation mechanism.
Incorrect Answers
A:A regional discount does not reserve unlimited zonal capacity.
B:Savings Plan charges relate to rate commitments, not dedicated AZ inventory.
C:Increasing an EC2 instance root EBS volume changes storage allocation but not whether a Reserved Instance applies regionally or to a specific Availability Zone. RI scope and capacity-reservation properties follow the purchased reservation attributes.
Question 885
A company has a database engine migration planned in three months. Finance wants to buy a long-term fixed RDS RI matching the existing engine and instance class, despite uncertain future usage. What caution is appropriate?
- Quantify remaining usage before the engine switch and the reservation eligibility afterward; avoid a new multi-year commitment tied to capacity likely to disappear.
- Buy a three-year no-upfront RDS Reserved DB Instance now, since no-upfront removes the obligation to pay for unused eligible DB instance-hours after migration.
- Purchase a current-engine reserved DB instance and plan to apply its benefits to a different database engine through RDS instance size normalization.
- Convert the intended RDS engine reservation into an EC2 Instance Savings Plan after migration so the current database commitment remains fully usable.
Explanation
Correct Answer
A:RDS reservation discounts depend on matching attributes, including eligible engine and class type. A planned engine migration can strand coverage, so commitment timing and post-migration spend should be modeled before purchase.
Incorrect Answers
B:No-upfront changes the timing of payment, not whether an eligible database remains in use for the commitment period. Unused reserved coverage can still create an effective cost.
C:RDS size flexibility applies to eligible instance sizes within a compatible class type and engine, not arbitrary database-engine changes. The planned engine switch may make existing reserved coverage inapplicable.
D:An RDS Reserved DB Instance is not a flexible EC2 Instance Savings Plan and cannot be transformed into one to cover a different family or service.
Question 886
A Spot-backed image rendering fleet loses instances mid-job. The task can recover from checkpoints, but intermediate state lives only on instance store and each interruption restarts a six-hour calculation. What design improves cost efficiency?
- Use instance-store as the sole durable checkpoint and assume all replacements inherit it.
- Save periodic checkpoints and durable progress metadata to S3 or another recoverable store before Spot interruption.
- Turn off Spot interruption handling because termination notices always preserve process memory.
- Increase backup CSV filename lengths rather than saving actual calculation state.
Explanation
Correct Answer
B:Spot savings are realized only if restart costs are controlled and completed work survives host reclaim events.
Incorrect Answers
A:Host-local ephemeral blocks do not transfer to a new Spot instance.
C:Instances can be interrupted and local application state may be lost.
D:A longer backup CSV filename is only metadata and cannot restore in-memory computation after an interrupted job. A recoverable batch workflow must checkpoint completed results to durable storage and resume from those checkpoints.
Question 887
A payment capture endpoint has stringent latency and cannot retry an interrupted transaction without customer impact. A team wants to run its entire base fleet solely on Spot to reduce hourly costs. Which mix is safer?
- Use 100% Spot for the only payment writer because Spot instances are guaranteed never to be interrupted during billing cycles.
- Remove transaction durability to shorten restart time after a Spot interruption.
- Maintain suitable On-Demand or reserved baseline capacity and use Spot only for truly interruption-tolerant surplus tasks with fallback.
- Rely on a Route 53 alias change to protect active in-memory transactions from host termination.
Explanation
Correct Answer
C:Reclaimable capacity alone is risky for strict noninterruptible service obligations.
Incorrect Answers
A:Spot reclaim is an explicit part of the pricing model.
B:Sacrificing durable payment state is inconsistent with correct financial processing.
D:DNS cutover cannot reconstruct an interrupted transaction without application recovery logic.
Question 888
An x86 EC2 application uses a commercial native database client compiled for x86. A price spreadsheet suggests Graviton instances are cheaper, so the team plans an in-place instance type change without rebuilding anything. What is the mandatory test?
- Assume every x86 binary executes natively on arm64 because both run Linux.
- Increase gp3 IOPS so the storage device translates the x86 library into ARM code.
- Change application load balancing to NLB as a substitute for recompiling incompatible native libraries.
- Verify ARM-compatible AMIs, native libraries and binaries and benchmark the actual Graviton workload before migration.
Explanation
Correct Answer
D:Graviton uses arm64, so x86-only native components must be replaced, rebuilt or supported through an explicitly viable compatibility strategy.
Incorrect Answers
A:Operating system family does not make processor instruction sets compatible.
B:Block storage throughput has no instruction translation feature.
C:Transport routing does not solve runtime ABI constraints.
Question 889
A cheap burstable EC2 instance has half the hourly cost of the current memory-intensive web node, but it swaps heavily under real request load and doubles response time. How should the cost decision be made?
- Compare cost per successfully served request while meeting memory, CPU and latency SLOs, not just the posted hourly price.
- Pick the lowest hourly instance regardless of memory exhaustion and response-time failures.
- Scale only network security group rules and assume the smaller instance gains RAM.
- Ignore workload throughput during pricing because all instance families have identical performance per vCPU.
Explanation
Correct Answer
A:Underpowered hosts can require additional replicas or violate service goals, eliminating apparent unit-price savings.
Incorrect Answers
B:A nominal discount is not economical if the required workload cannot run acceptably.
C:Changing security-group rules modifies permitted network traffic, not the amount of physical memory available to the EC2 instance. An application with documented RAM pressure needs an instance size or architecture that satisfies its memory footprint.
D:Two EC2 instance families with the same vCPU count can differ in memory, CPU architecture, network bandwidth and burst characteristics. Cost per completed workload, not an assumed identical per-vCPU performance, determines the economic choice.
Question 890
A service moves x86 workers to Graviton and gains a moderate price/performance advantage, but still pays for dozens of idle oversize instances around the clock. What broader optimization should accompany architecture choice?
- Treat a Graviton migration as proof every remaining idle instance is free.
- Right-size and autoscale the fleet, then model eligible longer-term commitments against its true steady baseline.
- Purchase commitments for peak capacity before measuring the new workload baseline.
- Buy long-term compute commitments for the current oversized, continuously idle instance inventory before measuring and right-sizing the post-migration baseline.
Explanation
Correct Answer
B:CPU architecture is only one cost dimension; unused capacity and pricing coverage can dominate monthly spending.
Incorrect Answers
A:Graviton instances still accrue compute charges while running.
C:Poorly sized commitments can lock in costs for idle resources.
D:A commitment may discount eligible spend, but locking in an unnecessarily large baseline can preserve structural waste. First size the workload correctly, then model coverage against stable demand.
