CLF-C02 Cloud Concepts — Timed 100 Questions

Question 1

A company runs a critical e-commerce application on Amazon EC2 instances distributed across multiple Availability Zones in a single AWS Region. The application is designed so that if an entire Availability Zone experiences an outage, the application continues to serve traffic from the remaining Availability Zones without interruption. Which benefit or characteristic of cloud computing does this scenario BEST represent?

100 minute time limit — choose an answer to begin.

Accepted Answer

Fault tolerance. The scenario describes an application that continues to operate without interruption when an entire Availability Zone fails. This is the definition of fault tolerance, which refers to a system's ability to remain fully operational with no downtime even when components fail. While high availability also uses redundancy across multiple Availability Zones, it typically allows for minimal downtime during failover. Fault tolerance goes further by eliminating any interruption, making it the best fit for the 'without interruption' condition described.

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Elasticity

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High availability

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Scalability

Question 2

A company's application runs on multiple AWS services across different geographic regions. The development team needs to access and manage these resources from their office using standard web browsers and API calls over the internet. The team does not need any dedicated private network connections. Which essential characteristic of cloud computing does this scenario best demonstrate?

Accepted Answer

Broad network access. Broad network access is the correct answer because the scenario describes accessing AWS resources over the internet using standard web browsers and API calls, without requiring dedicated private network connections. This characteristic ensures that cloud services are available from any standard device (e.g., laptops, smartphones) using standard protocols such as HTTPS (port 443) and RESTful APIs, which is exactly what the development team needs.

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Rapid elasticity

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Resource pooling

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Measured service

Question 3

According to the AWS Well-Architected Framework, which design principle is most closely associated with the recommendation to 'stop spending money on undifferentiated heavy lifting'?

Accepted Answer

Use managed services to reduce operational burden. The AWS Well-Architected Framework's principle of 'stop spending money on undifferentiated heavy lifting' is part of the Cost Optimization pillar. It directly advocates for using managed services to offload operational tasks like patching, scaling, and hardware maintenance. By leveraging services such as Amazon RDS (instead of self-managed databases) or AWS Lambda (instead of managing servers), you reduce the operational burden and focus on business differentiation. This aligns with the Cost Optimization pillar's goal of focusing spending on business value rather than undifferentiated activities.

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Design for failure

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Implement least-privilege access controls

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Automate infrastructure provisioning

Question 4

Drag and drop the steps to create an IAM user with programmatic access and attach a policy in the correct order.

Accepted Answer

Step 1: Create the IAM user. Step 2: Attach a policy to the user. Step 3: Enable programmatic access (generate access keys). Step 4: Securely store the access key ID and secret access key.. The correct sequence is: Step 1: Create the IAM user. Step 2: Attach a policy to the user to grant permissions. Step 3: Enable programmatic access (generate access keys). Step 4: Securely store the access key ID and secret access key. This matches option C. In the AWS IAM console, when creating a user, you select programmatic access, attach policies, and then the access keys are generated upon final creation. Generating keys before attaching a policy (as in option A) does not follow the standard best-practice order.

Answer

Step 1: Create the IAM user. Step 2: Enable programmatic access (generate access keys). Step 3: Attach a policy to the user. Step 4: Securely store the access key ID and secret access key.

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Step 1: Enable programmatic access (generate access keys). Step 2: Create the IAM user. Step 3: Attach a policy to the user. Step 4: Securely store the access key ID and secret access key.

Answer

Step 1: Enable programmatic access (generate access keys). Step 2: Attach a policy to the user. Step 3: Create the IAM user. Step 4: Securely store the access key ID and secret access key.

Question 5

Drag and drop the steps to troubleshoot an EC2 instance that is not reachable via SSH in the correct order.

Accepted Answer

1. Verify the instance has a public IP address. 2. Check security group inbound rules allow SSH. 3. Check network ACL allows SSH inbound/outbound. 4. Check route table has a route to an internet gateway.. The correct order starts with verifying the instance has a public IP, as without it no external connectivity is possible. Next, check security group inbound rules for SSH (port 22) because security groups act as a virtual firewall at the instance level. Then, check network ACLs for inbound and outbound rules, as NACLs provide stateless filtering at the subnet level. Finally, ensure the route table has a route to an internet gateway, allowing traffic to leave the subnet.

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1. Check system logs (e.g., cloud-init output). 2. Check security group inbound rules. 3. Check network ACL. 4. Verify the instance has a public IP.

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1. Check network ACL. 2. Check security group inbound rules. 3. Check route table. 4. Verify the instance has a public IP.

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1. Check security group inbound rules. 2. Check route table. 3. Check network ACL. 4. Check system logs.

Question 6

A company is migrating its on-premises applications to the AWS Cloud. The Chief Security Officer wants to confirm the division of security responsibilities. According to the AWS Shared Responsibility Model, which of the following tasks is the customer's responsibility?

Accepted Answer

Managing network access control lists (ACLs) for the customer's VPC. Managing network access control lists (ACLs) for a customer's VPC is explicitly a customer responsibility under the AWS Shared Responsibility Model. Customers control inbound and outbound traffic at the subnet level by configuring NACLs, which are stateless firewall rules. AWS provides the infrastructure and the VPC service, but the customer must define and manage the ACL rules to enforce network segmentation and security.

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Ensuring the physical security of AWS data centers

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Patching the hypervisor layer that runs Amazon EC2 instances

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Replacing defective hardware components in the AWS global infrastructure

Question 7

A retail company runs a legacy application on a single on-premises server. The application experiences unpredictable traffic surges that degrade performance. The company is considering migrating to the AWS Cloud. Which cloud computing characteristic MOST directly addresses the ability to automatically adjust resources to meet changing demand without manual intervention?

Accepted Answer

Elasticity. Elasticity is the cloud computing characteristic that enables automatic resource provisioning and de-provisioning to match demand in real time, without manual intervention. For the retail company's legacy application with unpredictable traffic surges, elasticity directly addresses the need to dynamically scale resources up during spikes and down during lulls, which is distinct from the planned, manual scaling of scalability.

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Scalability

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High availability

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Durability

Question 8

A startup is deploying a web application on Amazon EC2 instances across multiple Availability Zones (AZs). The architecture must ensure that the application remains fully operational and available to users even if one entire AZ fails. Which cloud computing concept does this requirement MOST directly represent?

Accepted Answer

Fault tolerance. Fault tolerance is the correct concept because the requirement specifies that the application must remain fully operational and available even if an entire Availability Zone fails. By deploying EC2 instances across multiple AZs and using an Elastic Load Balancer to distribute traffic, the architecture can withstand the failure of one AZ without any interruption in service, which is the essence of fault tolerance.

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Elasticity

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Scalability

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Resource pooling

Question 9

A mid-size company is planning to migrate its IT infrastructure to the AWS Cloud. The Chief Information Officer (CIO) expresses concern that multiple customers' virtual servers might run on the same physical hardware, potentially increasing the risk of data exposure. Which cloud computing characteristic describes this shared infrastructure model, where computing resources are pooled to serve multiple customers using a multi-tenant model?

Accepted Answer

Resource pooling. Resource pooling is the correct answer because it directly describes the multi-tenant model where the provider's computing resources (such as physical servers, storage, and network) are pooled to serve multiple customers. In AWS, this is achieved through hypervisor-level isolation (e.g., Xen or Nitro hypervisors) that allows multiple virtual servers (EC2 instances) to run on the same physical host while maintaining strict memory and I/O separation, preventing data exposure between tenants.

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On-demand self-service

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Measured service

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Broad network access

Question 10

A company based in Germany needs to store and process customer data that, by law, must remain within the European Union (EU). The company plans to use AWS services. Which AWS Global Infrastructure element is the MOST important for the company to evaluate when choosing where to deploy its resources?

Accepted Answer

AWS Regions. AWS Regions are geographically isolated areas that contain multiple Availability Zones. Since the company must ensure customer data remains within the EU by law, choosing the correct AWS Region (e.g., eu-central-1 in Frankfurt) is the primary mechanism to guarantee data residency. Only by deploying resources in an EU-based Region can the company meet legal data sovereignty requirements.

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Availability Zones

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Edge Locations

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Local Zones

Question 11

A company is currently running its IT infrastructure in an on-premises data center. The finance department wants to understand how moving to the AWS Cloud would change the company's cost structure. In particular, they want to avoid large upfront hardware purchases and instead pay only for the resources they consume on a monthly basis. Which key cloud computing concept does this shift represent?

Accepted Answer

Pay-as-you-go pricing. Pay-as-you-go pricing is the cloud computing model that allows a company to avoid large upfront capital expenditures on hardware and instead pay only for the resources they consume on a monthly basis. This directly aligns with the finance department's goal of shifting from a capital expenditure (CapEx) model to an operational expenditure (OpEx) model, where costs are incurred based on actual usage rather than upfront purchases.

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Elasticity

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Economies of scale

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High availability

Question 12

A company wants its employees to access cloud applications and manage cloud resources from anywhere using a variety of devices, including laptops, smartphones, and tablets. Which essential characteristic of cloud computing does this requirement directly represent?

Accepted Answer

Broad network access. The requirement for employees to access cloud applications and manage resources from anywhere using laptops, smartphones, and tablets directly represents broad network access. This essential characteristic means that cloud services are available over standard network protocols (e.g., HTTP/HTTPS, SSH) and can be accessed by heterogeneous client platforms, including mobile devices, workstations, and tablets, without requiring location-specific infrastructure.

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On-demand self-service

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Resource pooling

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Measured service

Question 13

A company runs an e-commerce website on Amazon EC2 instances behind an Application Load Balancer. The marketing team plans to run flash sales several times a year, which cause unpredictable but massive traffic spikes. The operations team wants the infrastructure to automatically add new EC2 instances when traffic increases and remove them when traffic decreases, without any manual intervention. Which cloud computing concept does this requirement MOST directly represent?

Accepted Answer

Elasticity. The requirement to automatically add EC2 instances during traffic spikes and remove them when traffic decreases directly represents elasticity. Elasticity is the ability to dynamically scale resources up or down based on real-time demand, which is precisely what the operations team needs for unpredictable flash sales. AWS Auto Scaling groups, integrated with the Application Load Balancer, automatically launch or terminate EC2 instances based on CloudWatch alarms (e.g., CPU utilization or request count), matching capacity to load without manual intervention.

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Scalability

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High availability

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Fault tolerance

Question 14

A small e-commerce company currently hosts its website on a single physical server in a colocation facility. The company pays a fixed monthly fee for the server, power, and bandwidth, regardless of actual usage. The CTO is evaluating AWS and notes that AWS operates millions of servers across multiple data centers, allowing it to negotiate lower prices for hardware and pass those savings to customers. The CTO expects that migrating to AWS will reduce the company's per-unit costs. Which benefit of cloud computing does this scenario BEST describe?

Accepted Answer

Economy of scale. The scenario describes how AWS leverages its massive scale of operations—millions of servers across multiple data centers—to negotiate lower hardware prices from suppliers and pass those savings to customers. This is the definition of economy of scale: as the volume of production increases, the cost per unit decreases. The CTO expects that migrating to AWS will reduce the company's per-unit costs, which directly aligns with this cloud computing benefit.

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High availability

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Elasticity

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Fault tolerance

Question 15

A financial services company is required by regulation to keep all customer transaction data on-premises. However, they want to use AWS to run analytics workloads on this data using Amazon EMR and Amazon S3 for temporary storage of intermediate results. They need a solution that connects their on-premises network to AWS securely and allows them to extend their on-premises environment into the AWS Cloud. Which cloud computing deployment model does this scenario BEST describe?

Accepted Answer

Hybrid cloud. The scenario describes a hybrid cloud deployment model, where the company maintains on-premises infrastructure for regulatory compliance (keeping customer transaction data on-premises) while leveraging AWS public cloud services (Amazon EMR and Amazon S3) for analytics workloads. The requirement to connect the on-premises network to AWS securely and extend the on-premises environment into the AWS Cloud is a defining characteristic of hybrid cloud, often implemented using AWS Direct Connect or VPN connections to create a unified network.

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Public cloud

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Private cloud

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Community cloud

Question 16

A company's development team frequently needs temporary test environments. A developer can log into the AWS Management Console, select an Amazon EC2 instance type, configure storage, and launch the instance within minutes without any interaction with the IT infrastructure team. This capability is an example of which essential characteristic of cloud computing?

Accepted Answer

On-demand self-service. The scenario describes a developer independently provisioning EC2 instances without requiring IT intervention. This directly matches the 'on-demand self-service' characteristic of cloud computing, where users can provision computing resources as needed automatically, without requiring human interaction with each service provider.

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Resource pooling

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Measured service

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Rapid elasticity

Question 17

A financial services company runs a high-frequency stock trading platform on AWS. The platform must continue processing trades without any interruption, even if an entire AWS Availability Zone experiences a complete outage. The architecture is designed with duplicate infrastructure in multiple Availability Zones, and all components are active simultaneously. The system is engineered so that if one AZ fails, the remaining AZs continue processing trades instantly, with zero downtime for end users. Which cloud computing concept does this requirement BEST represent?

Accepted Answer

Fault tolerance. This requirement describes a system that continues to operate without any interruption even when an entire AWS Availability Zone fails. That is the definition of fault tolerance: the system is designed to survive component failures with zero impact on service. The architecture uses duplicate active infrastructure in multiple AZs so that if one AZ fails, the remaining AZs instantly take over with no downtime, which is fault tolerance, not just high availability.

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Elasticity

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High availability

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Durability

Question 18

A company traditionally purchases physical servers every three years to host its internal applications. The company is migrating these applications to AWS and will pay a monthly fee based on the actual compute capacity consumed. The company no longer needs to make large upfront hardware purchases and can instead budget for smaller monthly payments. Which benefit of cloud computing does this scenario BEST describe?

Accepted Answer

Conversion of capital expense to operational expense. This scenario describes the conversion of capital expense (CapEx) to operational expense (OpEx). Traditionally, purchasing physical servers requires a large upfront capital investment, which is a capital expense. By migrating to AWS and paying a monthly fee based on actual compute capacity consumed, the company shifts to a pay-as-you-go model, which is an operational expense. This allows the company to budget for smaller, predictable monthly payments instead of large, infrequent hardware purchases.

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Scalability

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Elasticity

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Economies of scale

Question 19

A company uses Amazon EC2 instances to run its workloads. The company's IT team does not know the exact physical server where each instance runs, and instances from multiple customers may be hosted on the same physical hardware. The team only specifies the AWS Region and Availability Zone. Which essential characteristic of cloud computing does this scenario BEST represent?

Accepted Answer

Resource pooling. Resource pooling is the correct answer because the scenario describes how AWS aggregates compute resources from multiple physical hosts into a shared pool, which is then dynamically assigned and reassigned to customers based on demand. The IT team has no control over or knowledge of the exact physical server, and instances from different customers can run on the same hardware, which is the defining behavior of resource pooling as defined by NIST SP 800-145.

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On-demand self-service

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Rapid elasticity

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Measured service

Question 20

A startup runs an e-commerce website on AWS. During flash sales, traffic can increase 10x in a few minutes. The startup uses an Auto Scaling group to automatically launch additional EC2 instances when CPU utilization exceeds 70% and terminate them when utilization drops below 30%. This approach ensures that the application always has enough capacity to handle the load without manual intervention, and they only pay for what they use. Which cloud computing concept does this scenario BEST illustrate?

Accepted Answer

Elasticity. Elasticity is the ability of a cloud system to automatically scale resources up or down based on demand. The Auto Scaling group dynamically adds EC2 instances when CPU utilization exceeds 70% and terminates them when it drops below 30%, ensuring capacity matches load without manual intervention. This pay-per-use model is a hallmark of elasticity, not just high availability or fault tolerance.

Answer

High availability

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Fault tolerance

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Disaster recovery