Core Services Overview — CLF-C02 practice questions

Practice questions for this topic, with explained answers.

Domain: Cloud Technology and Services ·100 questions · 30 easy · 40 intermediate · 30 hard · page 2 of 7

Question 16 clf-core-services-overview-016

Easy · Choose one

An application currently runs on a single Amazon EC2 instance in one Availability Zone. What is the most effective way to make it highly available within the same AWS Region?

  1. a Run several instances of the same size in the same Availability Zone
  2. b Change the instance to a larger instance type
  3. c Run instances in at least two Availability Zones behind an Elastic Load Balancer
  4. d Enable versioning on the Amazon S3 bucket the application uses
Show answer & explanation

Answer: C

Why C is correct

High availability within a Region is achieved by distributing workload across multiple Availability Zones, because AZs are designed to be isolated from each other's failures. Placing the instances behind an Elastic Load Balancer lets traffic be routed only to healthy targets, so the loss of an entire AZ does not take the application offline.

Why the others are wrong

  • A — All those instances share the same AZ. A failure affecting that Availability Zone would take down every instance at once.
  • B — A larger instance type provides more capacity (vertical scaling), but it is still a single instance in a single AZ and therefore still a single point of failure.
  • D — S3 versioning protects object data from accidental overwrite or deletion. It does nothing for the availability of the compute layer.

Last verified: 2026-09-02

Question 17 clf-core-services-overview-017

Intermediate · Choose one

A team creates an Amazon S3 bucket in the us-east-1 Region and assumes that AWS will automatically keep a copy of the objects in the eu-west-1 Region for resilience. Which statement is correct?

  1. a AWS automatically copies all Amazon S3 data to at least one other Region at no additional charge
  2. b AWS Regions are isolated from one another, so data stays in the selected Region unless the customer explicitly configures replication such as S3 Cross-Region Replication
  3. c Amazon S3 buckets are global resources and therefore exist in all Regions simultaneously
  4. d Amazon S3 data is automatically replicated to every Region in the same continent
Show answer & explanation

Answer: B

Why B is correct

AWS Regions are designed to be isolated from each other so that a problem in one Region does not affect another, and so that customers retain control over where their data resides. AWS does not move or copy customer content between Regions unless the customer configures a feature that does so, such as S3 Cross-Region Replication or a snapshot copy.

Why the others are wrong

  • A — No automatic cross-Region copying occurs, and cross-Region replication incurs both storage and data transfer charges when it is enabled.
  • C — A bucket is created in one Region and its data resides there. Although bucket names are globally unique, the bucket itself is a Regional resource.
  • D — There is no continent-level automatic replication. Multi-Region resilience is always an explicit customer configuration.

Last verified: 2026-09-02

Question 18 clf-core-services-overview-018

Intermediate · Choose one

An application has a web tier and a database tier that exchange a high volume of chatty, latency-sensitive traffic. The business requires the application to survive the loss of an entire data center, but it wants to avoid cross-Region data transfer charges and added network latency between the tiers. What should the architect do?

  1. a Deploy the web and database tiers across at least two Availability Zones within a single AWS Region
  2. b Deploy the web tier in one AWS Region and the database tier in a different AWS Region
  3. c Deploy the web tier at Amazon CloudFront edge locations and keep the database in one Availability Zone
  4. d Deploy every tier into a single Availability Zone and take frequent snapshots
Show answer & explanation

Answer: A

Why A is correct

Availability Zones are physically separate facilities with independent power, cooling, and networking, so spreading the tiers across two or more Availability Zones survives the loss of an entire data center. Because Availability Zones in a Region are linked by high-bandwidth, low-latency private networking, inter-tier chatter stays fast, and no cross-Region data transfer charges are incurred.

Why the others are wrong

  • B — Splitting tiers across Regions puts hundreds or thousands of miles between the web and database tiers, which adds latency to every query and incurs cross-Region data transfer charges. Multi-Region designs replicate whole stacks rather than splitting a single stack.
  • C — Edge locations serve cached content and do not host an application's web tier, and leaving the database in one Availability Zone still leaves a single point of failure.
  • D — A single Availability Zone is a single data center location, so the design fails the requirement. Snapshots help recovery but do not keep the application running.

Last verified: 2026-09-02

Question 19 clf-core-services-overview-019

Intermediate · Choose one

A hospital must keep certain patient processing workloads physically inside its own building to satisfy regulators, but it wants to use the same AWS services, APIs, and management tools it uses in the cloud. Which AWS offering meets this requirement?

  1. a AWS Storage Gateway
  2. b Amazon Lightsail
  3. c AWS Outposts
  4. d AWS Direct Connect
Show answer & explanation

Answer: C

Why C is correct

AWS Outposts delivers AWS-designed and AWS-managed infrastructure racks or servers to the customer's own data center or colocation space. It runs a consistent set of AWS services locally and uses the same APIs, control plane, and tools as the AWS Region, which makes it the fit for data that must physically remain on premises.

Why the others are wrong

  • A — Storage Gateway provides on-premises access to cloud storage, but it addresses only storage, not the compute workload the hospital must run locally.
  • B — Amazon Lightsail is a simplified way to run virtual servers within an AWS Region. It has no on-premises deployment option.
  • D — AWS Direct Connect provides a dedicated private network link from the hospital to an AWS Region. It moves traffic to AWS rather than allowing the workload itself to run inside the hospital building.

Last verified: 2026-09-02

Question 20 clf-core-services-overview-020

Intermediate · Select 2 answers

Which TWO of the following are valid reasons for a company to deploy the same workload in more than one AWS Region? (Choose TWO.)

  1. a To automatically receive a lower per-GB price for Amazon S3 storage
  2. b To eliminate the need to take backups of production data
  3. c To remove the need to configure IAM policies in the secondary Region
  4. d To continue operating if an event affects an entire AWS Region
  5. e To satisfy a regulation requiring that citizens' data be stored within a specific country
Show answer & explanation

Answer: D and E

Why D and E are correct

Regions are isolated from one another, so running in more than one Region is the standard approach to surviving a Region-wide event as part of a disaster recovery strategy. Multiple Regions also let a company place data in a specific country to satisfy data sovereignty or residency laws, and they can reduce latency for users spread across the world.

Why the others are wrong

  • A — Amazon S3 pricing varies by Region and is not discounted simply because a customer uses more than one Region.
  • B — Replication across Regions protects against a Region failure, but it also replicates accidental deletions and corruption. Backups remain necessary.
  • C — IAM is a global service, but permissions and resource policies still have to be designed and applied for the resources in every Region. Nothing is removed.

Last verified: 2026-09-02

Question 21 clf-core-services-overview-021

Intermediate · Choose one

A gaming company runs UDP-based multiplayer game servers on Amazon EC2 in three AWS Regions. It needs two static IP addresses that never change, wants player traffic to enter the AWS global network as close to the player as possible, and needs near-instant failover if a Regional endpoint becomes unhealthy. Which service should it use?

  1. a An Application Load Balancer in each Region
  2. b AWS Global Accelerator
  3. c Amazon CloudFront
  4. d Amazon Route 53 with a simple routing policy
Show answer & explanation

Answer: B

Why B is correct

AWS Global Accelerator provides two static anycast IP addresses that act as a fixed front door for the application. Traffic enters the AWS global network at the edge location nearest the user and is routed over the AWS backbone to the healthiest endpoint. It supports TCP and UDP, and because clients keep using the same static IPs, failover between Regions does not depend on DNS caching.

Why the others are wrong

  • A — An Application Load Balancer is Regional and operates at Layer 7 for HTTP and HTTPS. It neither handles UDP nor provides a global entry point.
  • C — Amazon CloudFront is optimized for cacheable HTTP and HTTPS content. It does not front UDP game traffic.
  • D — Route 53 is DNS-based. Failover depends on TTL expiry and client-side DNS caching, so it is not near-instant, and it does not provide static anycast IP addresses.

Last verified: 2026-09-02

Question 22 clf-core-services-overview-022

Hard · Choose one

A European company must guarantee that its customer records are never stored outside the European Union. Which action most directly enforces this requirement?

  1. a Enable Amazon S3 default encryption on all buckets
  2. b Enable Amazon CloudFront so that requests are served from EU edge locations
  3. c Purchase an AWS Enterprise Support plan and open a case requesting EU-only storage
  4. d Provision and store the data only in AWS Regions located in the EU, since AWS does not move customer data out of a Region unless the customer configures it
Show answer & explanation

Answer: D

Why D is correct

AWS Regions are isolated from one another, and customers choose the Region in which their data is stored. AWS does not replicate or move customer content out of the selected Region unless the customer explicitly configures a service to do so. Therefore, selecting EU Regions is the direct control for an EU data residency requirement.

Why the others are wrong

  • A — Encryption protects data confidentiality. It has no effect on the geographic location where the data physically resides.
  • B — CloudFront caches content at edge locations worldwide, which could actually place copies of content outside the EU rather than restrict it.
  • C — Support plans provide technical guidance and faster response times. They do not change where data is stored, and no case is needed because Region selection is a customer setting.

Last verified: 2026-09-02

Question 23 clf-core-services-overview-023

Hard · Select 2 answers

A solutions architect is choosing which AWS Region to deploy a new workload into. Which TWO factors are most relevant to that decision? (Choose TWO.)

  1. a Whether the Region allows more than five IAM users to be created
  2. b Proximity to the application's end users, because it affects network latency
  3. c Whether all of the AWS services the workload requires are available in that Region
  4. d The version of the AWS CLI that the Region supports
  5. e The number of edge locations physically located inside the Region
Show answer & explanation

Answer: B and C

Why B and C are correct

The four standard Region selection criteria are latency (proximity to users), service availability (not every service or feature launches in every Region at the same time), pricing (service prices differ by Region), and compliance or data governance requirements. Proximity to users and service availability are two of these.

Why the others are wrong

  • A — IAM is a global service and is not limited per Region in this way. IAM user quotas are account-level, not Region-level.
  • D — The AWS CLI is a client-side tool. Its version is not determined by the Region.
  • E — Edge locations are part of the separate global edge network and are not a property of a Region. They are not counted when choosing a Region for a workload.

Last verified: 2026-09-02

Question 24 clf-core-services-overview-024

Hard · Choose one

A company hosts a static marketing website on Amazon S3 in the us-east-1 Region. Users in Australia and Japan report slow page loads, while users in the United States are satisfied. Which change addresses the problem with the least cost and operational effort?

  1. a Place the S3 bucket behind AWS Global Accelerator
  2. b Move the website onto larger Amazon EC2 instances
  3. c Replicate the website into AWS Regions in Australia and Japan and manage the copies
  4. d Create an Amazon CloudFront distribution in front of the S3 bucket
Show answer & explanation

Answer: D

Why D is correct

CloudFront caches the static assets at edge locations around the world, so users in Australia and Japan are served from a nearby edge rather than from us-east-1. This is the standard, low-effort way to reduce latency for globally distributed users of static content, and it also reduces load and data transfer costs at the origin.

Why the others are wrong

  • A — Global Accelerator improves routing for non-cacheable and non-HTTP workloads. It does not cache content, so it is not the right tool for static website acceleration and would not help as much as CloudFront.
  • B — The site is served from S3, not EC2, so there are no instances to resize. Compute size is not the bottleneck; geographic distance is.
  • C — Replicating into multiple Regions works but introduces ongoing synchronization, DNS, and cost overhead. It is far more operational effort than a CDN for static content.

Last verified: 2026-09-02

Question 25 clf-core-services-overview-025

Hard · Choose one

Which statement about Availability Zones within a single AWS Region is TRUE?

  1. a Traffic between Availability Zones must traverse the public internet
  2. b Each Region contains exactly one Availability Zone
  3. c They share the same power source and cooling infrastructure to keep latency low
  4. d They are physically separated but connected to each other by high-bandwidth, low-latency, fully redundant private networking
Show answer & explanation

Answer: D

Why D is correct

Availability Zones in a Region are physically separated by a meaningful distance to reduce the chance that a single event affects more than one, yet they are close enough to be linked by high-bandwidth, low-latency, fully redundant, dedicated metro fiber. That combination is what makes synchronous replication across AZs practical.

Why the others are wrong

  • A — Inter-AZ traffic travels over the AWS private network, not the public internet.
  • B — Every AWS Region contains multiple Availability Zones. Design guidance for high availability depends on there being more than one.
  • C — Each Availability Zone has independent power, cooling, and physical security precisely so that a failure in one does not cascade to another.

Last verified: 2026-09-02

Question 26 clf-core-services-overview-026

Hard · Choose one

An application team wants to reduce the load on its origin servers and shorten response times for users repeatedly requesting the same product images. Which characteristic of edge locations makes this possible?

  1. a Content is cached at the edge, so repeat requests are served without reaching the origin
  2. b Edge locations automatically replicate the origin database to every continent
  3. c Edge locations run the application's EC2 instances closer to users
  4. d Edge locations increase the CPU allocated to the origin servers
Show answer & explanation

Answer: A

Why A is correct

Edge locations cache copies of content. When a subsequent request for the same object arrives, CloudFront serves it directly from the edge cache. This shortens the network path for the user and means the origin never sees that request, which lowers origin load and origin data transfer cost.

Why the others are wrong

  • B — Edge locations cache content objects. They do not replicate databases.
  • C — Edge locations are part of the content delivery network. Customers do not launch general EC2 instances in them.
  • D — Edge locations do not change the compute capacity of origin servers; they reduce how often the origin is contacted.

Last verified: 2026-09-02

Question 27 clf-core-services-overview-027

Easy · Choose one

Which AWS service lets a developer run code in response to events without provisioning or managing any servers, and charges only for the compute time consumed?

  1. a Amazon EC2
  2. b AWS Elastic Beanstalk
  3. c AWS Lambda
  4. d Amazon Elastic Container Service (Amazon ECS) on EC2
Show answer & explanation

Answer: C

Why C is correct

AWS Lambda is a serverless compute service. You upload a function, and Lambda runs it in response to events such as an Amazon S3 upload, an Amazon API Gateway request, or an Amazon EventBridge rule. There are no servers to provision, patch, or scale, and billing is based on the number of requests and the duration the code runs at the configured memory size.

Why the others are wrong

  • A — Amazon EC2 provides virtual servers that the customer must select, launch, patch, scale, and pay for whether or not they are processing work.
  • B — Elastic Beanstalk automates deployment but still provisions EC2 instances, load balancers, and Auto Scaling groups in the customer's account, which the customer pays for continuously.
  • D — Running ECS tasks on EC2 launch type means the customer still owns and manages the underlying EC2 container instances.

Last verified: 2026-09-02

Question 28 clf-core-services-overview-028

Easy · Choose one

What is the maximum amount of time that a single AWS Lambda function invocation can run before it times out?

  1. a 5 minutes
  2. b 15 minutes
  3. c 1 hour
  4. d 24 hours
Show answer & explanation

Answer: B

Why B is correct

The maximum configurable Lambda function timeout is 900 seconds, which is 15 minutes. Any workload that needs to run longer than that should be redesigned into smaller steps, orchestrated with AWS Step Functions, or moved to a service such as AWS Batch, Amazon ECS, or Amazon EC2.

Why the others are wrong

  • A — 5 minutes was an older Lambda limit that was raised. The current maximum is 15 minutes.
  • C — Lambda cannot be configured to run for an hour. AWS Batch or ECS tasks are appropriate for jobs of that length.
  • D — 24 hours far exceeds the Lambda limit and describes a long-running batch or container workload instead.

Last verified: 2026-09-02

Question 29 clf-core-services-overview-029

Easy · Choose one

Which AWS service provides a fully managed, private registry for storing, managing, and deploying container images?

  1. a Amazon Elastic Container Service (Amazon ECS)
  2. b Amazon Simple Storage Service (Amazon S3)
  3. c Amazon Elastic Container Registry (Amazon ECR)
  4. d Amazon Elastic Kubernetes Service (Amazon EKS)
Show answer & explanation

Answer: C

Why C is correct

Amazon ECR is a fully managed container image registry. It stores, manages, and deploys container images, integrates with IAM for access control, and works directly with Amazon ECS, Amazon EKS, and AWS Fargate.

Why the others are wrong

  • A — Amazon ECS is a container orchestration service. It runs and schedules containers, but it pulls the images from a registry such as ECR.
  • B — Amazon S3 stores objects of any type, but it is not a container registry and does not implement the container image APIs that ECS and EKS expect.
  • D — Amazon EKS is a managed Kubernetes service for orchestrating containers. Like ECS, it consumes images from a registry rather than storing them.

Last verified: 2026-09-02

Question 30 clf-core-services-overview-030

Easy · Choose one

Which AWS service automatically adds or removes Amazon EC2 instances so that an application maintains the capacity it needs as demand changes?

  1. a Amazon EC2 Auto Scaling
  2. b Amazon CloudWatch
  3. c Elastic Load Balancing
  4. d AWS Compute Optimizer
Show answer & explanation

Answer: A

Why A is correct

Amazon EC2 Auto Scaling maintains a group of instances between a minimum and maximum size and adjusts that number automatically based on scaling policies, schedules, or health checks. It is the mechanism that delivers elasticity for EC2-based workloads and also replaces instances that fail health checks.

Why the others are wrong

  • B — Amazon CloudWatch collects the metrics and can trigger the alarms that Auto Scaling policies react to, but CloudWatch itself does not launch or terminate instances.
  • C — Elastic Load Balancing distributes incoming traffic across the instances that exist. It does not create or terminate them.
  • D — AWS Compute Optimizer analyzes utilization and recommends better-suited resource configurations. It is advisory and does not change capacity automatically.

Last verified: 2026-09-02