Free Amazon Web Services SAA-C03 Practice Exam with Questions & Answers | Set: 13

Security groups are stateful, but they cannot explicitly deny traffic — only allow.

Network ACLs are stateless and support explicit deny rules.To prevent Application A from sending traffic to Application B, configure a deny outbound rule in the network ACL of Application A’s subnet to block traffic to Application B’s subnet.

“Unlike security groups, network ACLs support both allow and deny rules, enabling you to explicitly block traffic.”

— Network ACLs

This is the correct method to block outbound traffic between subnets.

To provide unique, secure URLs efficiently:

A: Create a wildcard custom domain in Route 53 as an alias for the API Gateway endpoint.

D: Request a wildcard certificate in ACM in the same Region as API Gateway (certificates must be in the same Region as the API).

F: Create a custom domain name in API Gateway and attach the certificate.

“You can configure a custom domain name for your API Gateway API. To use a wildcard certificate, request it from ACM in the same Region as your API.”

— API Gateway Custom Domain Names

This combination provides secure wildcard URLs without creating separate endpoints or hosted zones per user.

AWS Global Accelerator provides static anycast IP addresses that are announced from AWS edge locations. Traffic sent to these IPs is routed over the AWS global network to the nearest healthy endpoint (for example, an ALB or NLB) in any Region. Because clients connect to static IPs instead of DNS names that change, failover does not depend on DNS TTLs or client cache expiry, which avoids stale DNS entries.

You can register endpoints in multiple Regions and let Global Accelerator automatically fail over when health checks fail, all behind a single global endpoint.

CloudFront (Option A) is primarily for HTTP/HTTPS content caching and still uses DNS; it is not intended as a generic multi-Region failover solution for arbitrary applications.

Route 53 (Options B and D) relies on DNS; clients can cache DNS responses and may keep sending traffic to an unhealthy Region until TTLs expire, which does not meet the “avoid stale DNS client caches” requirement.

AWS Shield Advanced is designed to provide enhanced protection against DDoS attacks with proactive engagement and response capabilities, making it the best solution for this scenario.

AWS Shield Advanced: This service provides advanced protection against DDoS attacks. It includes detailed attack diagnostics, 24/7 access to the AWS DDoS Response Team (DRT), and financial protection against DDoS-related scaling charges. Shield Advanced also integrates with Route 53 and the Application Load Balancer (ALB) to ensure comprehensive protection for your web applications.

Route 53 and ALB Protection: By adding your Route 53 hosted zones and ALB resources to AWS Shield Advanced, you ensure that these components are covered under the enhanced protection plan. Shield Advanced actively monitors traffic and provides real-time attack mitigation, minimizing the impact of DDoS attacks on your application.

Why Not Other Options?:

Option A (AWS Config): AWS Config is a configuration management service and does not provide DDoS protection or detection capabilities.

Option B (AWS WAF): While AWS WAF can help mitigate some types of attacks, it does not provide the comprehensive DDoS protection and proactive engagement offered by Shield Advanced.

Option C (GuardDuty): GuardDuty is a threat detection service that identifies potentially malicious activity within your AWS environment, but it is not specifically designed to provide DDoS protection.

AWS References:

AWS Shield Advanced- Overview of AWS Shield Advanced and its DDoS protection capabilities.

Integrating AWS Shield Advanced with Route 53 and ALB- Detailed guidance on how to protect Route 53 and ALB with AWS Shield Advanced.

Amazon SQS FIFO queues are designed for workloads that require strict message ordering and exactly-once processing semantics. This makes FIFO the correct queue type for an order processing system that must preserve exact order. SQS also provides decoupling between producers and consumers, improving resilience because order ingestion does not depend on the processor being immediately available. AWS Lambda can poll SQS and process messages without managing servers, while the SQS queue buffers orders durably. A standard SQS queue does not guarantee exact ordering. SNS alone is a pub/sub service and does not provide the same ordered queue processing requirement. Kinesis can preserve ordering within shards, but using EC2 Spot Instances introduces interruption risk and unnecessary operational responsibility for this architecture.

S3 Intelligent-Tiering is designed for data with unknown or changing access patterns. It automatically moves objects between frequent and infrequent access tiers as needed, with no retrieval fees for accessing data in any tier, and no performance impact. Minimal management overhead is required because AWS manages all transitions automatically. This class is cost-optimized and meets all requirements listed.

AWS Documentation Extract:

" S3 Intelligent-Tiering is the only storage class that automatically moves data between frequent and infrequent access tiers when access patterns change, with no retrieval charges and no impact on performance. It is designed to optimize costs automatically when data access patterns are unpredictable. "

(Source: Amazon S3 documentation, Intelligent-Tiering storage class)

Other options:

B: Storage class analysis only provides recommendations, not actual storage tiering.

C & D: S3 Standard-IA and S3 One Zone-IA both have retrieval fees and may impact retrieval time and data durability.

This solution meets the requirement of encrypting each customer’s data separately with the least operational overhead by leveraging AWS Key Management Service (KMS).

Separate AWS KMS Keys: By creating separate KMS keys for each customer, you can ensure that each customer’s data is encrypted with a unique key. This approach satisfies the compliance requirement for separate encryption and provides fine-grained control over access to the keys.

Granular Access Control: AWS KMS allows you to define key policies and use IAM policies to grant specific permissions to the keys. This ensures that only authorized users or services can access the keys, thereby maintaining the principle of least privilege.

Logging and Monitoring: AWS KMS integrates with AWS CloudTrail, which logs all key usage and management activities. This provides an audit trail that is essential for meeting compliance requirements.

Why Not Other Options?:

Option A (Store keys in S3): Storing keys in S3 is not recommended because it does not provide the same level of security, access control, or integration with AWS services as KMS does.

Option B (Hardware security appliance): Deploying a hardware security appliance adds significant operational overhead and complexity, which is unnecessary given that KMS already provides a secure and centralized key management solution.

Option C (Single KMS key for all data): Using a single KMS key does not meet the requirement of encrypting each customer ' s data separately.

AWS References:

AWS Key Management Service (KMS)- Overview of KMS, its features, and best practices for key management.

Using AWS KMS for Multi-Tenant Applications- Guidance on how to design applications using KMS for multi-tenancy.

Service control policies (SCPs) in AWS Organizations apply to the accounts or OUs to which they are attached:

To restrict only nonproduction accounts, you can:

Attach the SCP directly to those specific member accounts (Option B), or

Create a dedicated OU for the nonproduction accounts and attach the SCP to that OU (Option E).

Both methods ensure that the deny policy affects only the nonproduction accounts and does not impact the production account.

Why the others are incorrect:

A: Attaching the SCP to the root OU would apply the deny to all accounts, including production, which does not meet the requirement.

C: SCPs attached to the management account only affect that account, not all member accounts.

D: Creating an OU for the production account and attaching the deny SCP there would block the prohibited instance types in production, which is the opposite of what is required.

Amazon CloudFront is a global content delivery network (CDN) that caches and distributes content to users with low latency. By setting the existing ALB as the origin, CloudFront can cache dynamic and static content closer to users worldwide, improving performance and reducing the load on the application servers. This is the most cost-optimized and AWS-recommended way to globally serve dynamic content for web applications.

Reference Extract:

" CloudFront accelerates delivery of both static and dynamic content, reducing latency and offloading origin resources by caching content at edge locations. "

Source: AWS Certified Solutions Architect – Official Study Guide, CloudFront and Global Application section.

Elastic Beanstalk traffic splitting is the best operationally efficient deployment option for testing a new application version with a controlled portion of live traffic. Traffic splitting is effectively a canary-style deployment that routes a defined percentage of production traffic to the new version while monitoring health before full rollout. This minimizes disruption because Elastic Beanstalk manages much of the deployment orchestration, health evaluation, and rollback behavior. Manually changing ALB listener rules adds unnecessary operational work and increases the chance of routing mistakes. Replacing all EC2 instances in the Auto Scaling group risks broader production impact. Lambda weighted aliases apply to Lambda functions and are not the correct deployment mechanism for an Elastic Beanstalk application running on EC2 behind an ALB.

AWS Fargate provides per-pod isolation for CPU, memory, storage, and networking, making it ideal for multi-tenant use cases.

AWS Documentation References:

EKS with Fargate

AWS CloudTrail Lakeis a fully managed service that allows the collection, storage, and querying ofCloudTrail eventsfor both AWS and non-AWS services. CloudTrail Lake can be customized to collect logs from various sources, ensuring a centralized audit solution. It also supports long-term storage, so logs can be retained for 7 years, meeting the compliance requirement.

Option A (Data Lake): Setting up a data lake in S3 introduces unnecessary operational complexity compared to CloudTrail Lake.

Option C (Ingest non-AWS services into CloudTrail): CloudTrail Lake is better suited for this task with less operational overhead.

Option D (CloudWatch Logs): While CloudWatch can store logs, CloudTrail Lake is specifically designed for API auditing and storage.

AWS References:

AWS CloudTrail Lake

A mix of On-Demand Instances and Spot Instances is the best cost-optimized option when the company wants lower cost but does not want long-term commitments. On-Demand Instances provide baseline reliability and require no upfront payment or term commitment. Spot Instances can significantly reduce compute cost for flexible portions of the Auto Scaling group, as long as the application can tolerate replacement capacity when Spot capacity is interrupted. Reserved Instances require a commitment, so options B and D violate the requirement. Dedicated Instances are generally used for compliance or isolation requirements and do not optimize cost for a scalable web application. Auto Scaling groups can use multiple purchasing options to balance availability and cost.

The correct answer isAbecause the company wants engineers to reach aspecific development EC2 instancethrough aRoute 53 hosted zone, while ensuring that traffic continues to route correctlyeven if the development instance is replaced. The best way to achieve this is to point the Route 53 record for the development website to theApplication Load Balancerand then configure anALB listener rulethat forwards requests for the development hostname to adedicated target groupcontaining the development instance.

This design works well because the ALB provides a stable endpoint, and Route 53 can alias the development DNS name to the ALB. If the development EC2 instance is replaced, the target group can simply register the new instance. The DNS record does not need to change, and engineers continue to use the same development URL. This minimizes operational effort and supports automatic continuity.

Option B is incorrect because using a public IP address for a specific instance does not automatically handle instance replacement unless additional manual steps are taken. Option C is incorrect because redirecting users to a public IP is not the intended design and introduces unnecessary exposure and management complexity. Option D is incorrect because placing all instances in the same target group would not ensure that requests for the development website are sent only to the specific development instance.

AWS best practices favor usingload balancers and target groupsas stable routing layers rather than binding DNS names directly to ephemeral instance IP addresses. Therefore, the most reliable and maintainable solution is to useRoute 53 + ALB + a dedicated target groupfor the development instance.

Amazon CloudFront is a content delivery network (CDN) service that caches copies of your content at edge locations around the world. This helps improve performance by serving content from the edge nearest to the user. However, when the content in Amazon S3 (your origin) is updated, those updates may not immediately reflect on the website if they are cached at the CloudFront edge locations.

The issue described in the question suggests that the CI/CD pipeline is functioning correctly, and updates are being deployed to S3. However, since CloudFront caches this content, the edge locations may still be serving outdated content, causing the updates to not be reflected on the website.

To resolve this issue, you need to invalidate the CloudFront cache. By invalidating the cache, CloudFront will remove the outdated content and retrieve the latest version from the S3 origin.

AWS documentation on this process:

CloudFront cache invalidation allows you to clear items from the cache so that CloudFront retrieves the latest version from the origin. You can create invalidation requests via the AWS Management Console, AWS CLI, or SDKs.

AWS CloudFront Documentation

Why the other options are incorrect:

A. Add an Application Load Balancer: ALBs are used to distribute incoming application traffic and are not relevant to caching or serving content from CloudFront.

B. Add Amazon ElastiCache for Redis or Memcached: This would help in caching database queries but has no relation to static website content hosted on CloudFront and S3.

D. Use AWS Certificate Manager (ACM): ACM is used for managing SSL/TLS certificates and is unrelated to the issue of content not being updated on CloudFront.

Amazon EFS is the correct solution because the application already expects a shared Linux file system and cannot be modified during migration. EFS supports the NFS protocol, can be mounted by multiple EC2 instances in an Auto Scaling group, and scales automatically as files are added or removed. Mount targets in multiple Availability Zones provide high availability for the shared file system. Because the documents are stored once and retrieved later for reference, EFS Standard-IA reduces storage cost for infrequently accessed files while preserving file-system access semantics. A self-managed NFS server on EC2 creates a single point of failure and management burden. S3 and SFTP do not preserve the existing NFS shared-file-system behavior without application changes.

This question focuses on scalability, operational overhead, and performance during unpredictable workloads.

API Gateway + AWS Lambda enables serverless compute, which scales automatically based on the number of requests. It requires no provisioning, maintenance, or patching of servers — eliminating operational overhead.

Amazon DynamoDB is a fully managed NoSQL database optimized for high-throughput workloads with single-digit millisecond latency.

Amazon S3 is designed for high availability and durability, and is ideal for storing unstructured content such as user-uploaded images.

By leveraging these fully managed and scalable services, the architecture meets the requirement of supporting rapid user growth while minimizing operational complexity. This solution aligns with the Performance Efficiency and Operational Excellence pillars in the AWS Well-Architected Framework.

???? References:

Serverless Web Application Architecture

Using DynamoDB with Lambda

Best Practices for API Gateway

Amazon Route 53 health checks can automatically perform DNS failover to healthy endpoints. When integrated with an Application Load Balancer, this provides a highly resilient system architecture that automatically routes traffic to healthy resources across Regions or endpoints.

From AWS Documentation:

“Route 53 DNS failover automatically routes traffic away from unhealthy resources and directs it to healthy resources that you specify in DNS records.”

(Source: Amazon Route 53 Developer Guide – DNS Failover)

Why B is correct:

Route 53 health checks automatically monitor endpoint health and switch to a healthy target when the primary endpoint fails.

The failover process is automatic, with no manual updates to DNS records required.

Combined with ALB’s built-in multi-AZ resilience, this provides maximum availability.

Why others are incorrect:

A & C: Require manual DNS updates, which are not automatic and introduce latency.

D: Creating new ALBs during failover increases downtime and is operationally inefficient.

When using imported key material with AWS KMS, you maintain control over the key lifecycle. AWS KMS allows you to import new key material into an existing KMS key (of type " external " or " imported " ), thus rotating the key material without changing the key ID or ARNs. This enables applications to continue using the same key for cryptographic operations without disruption.

You can also set an expiration time for the old key material, after which AWS KMS deletes the old material and requires new key material to be imported, enforcing regular rotation per your compliance requirements.

AWS Documentation Extract:

" To rotate imported key material, you can re-import new key material into the same KMS key. This retains the same key ID and ARNs so applications are unaffected. You can set an expiration time for imported key material and replace it as needed, ensuring compliance with your rotation policy. "

(Source: AWS Key Management Service Developer Guide, Importing Key Material, Rotating Key Material)

Other options:

A: You cannot create a new KMS key with the same key ID as an existing one.

B: Deleting and recreating the key disrupts application access because the key ID changes.

D: Automatic rotation is only available for AWS-managed keys, not for imported key material.

AWS recommends using cost allocation tags to associate costs with owners (e.g., department, project) and AWS Budgets to create cost or usage budgets with alerts at defined thresholds (e.g., 60%). Budgets can send notifications via email or Amazon SNS when “Actual or forecasted” spend exceeds the threshold. Cost Explorer forecasts help visualize trends but do not provide budget alerting or ownership attribution by themselves. Trusted Advisor does not generate budget threshold alerts. Therefore, tagging resources for accountability and setting a budget with a 60% alert provides governance and proactive notifications aligned with cost control best practices for experimentation.