Amazon Web Services SAA-C03 AWS Certified Solutions Architect - Associate (SAA-C03) Exam Practice Test

Amazon API Gateway supports multiple API types: REST, HTTP, WebSocket, and gRPC. HTTP APIs are a newer, lightweight option that support JWT authorizers natively, enabling secure, scalable authentication for APIs with JSON Web Tokens.

HTTP APIs can integrate with ALBs as a backend target, providing direct connectivity and simplified API management with JWT authentication built in.

REST APIs support JWT but are more feature-rich and complex, often used for legacy or more complex use cases, and have higher costs and latency. WebSocket APIs are for real-time, bidirectional communication, which is not requested here. gRPC APIs support RPC calls but are less common for public HTTP-based APIs with JWT auth.

Therefore, HTTP API with JWT authorizers is the best fit for this use case.

Storage Gateway Volume Gateway (Cached Volumes): This configuration allows you to store your primary data in Amazon S3 while retaining frequently accessed data locally in a cache for low-latency access.

Low-Latency Access: Frequently accessed data is cached locally on-premises, providing low-latency access while the less frequently accessed data is stored cost-effectively in Amazon S3.

Implementation:

Deploy a Storage Gateway appliance on-premises or in a virtual environment.

Configure it as a volume gateway with cached volumes.

Create volumes and configure your applications to use these volumes.

Minimal Infrastructure Changes: This solution integrates seamlessly with existing on-premises infrastructure, requiring minimal changes and reducing dependency on on-premises storage servers.

Amazon S3 File Gateway (AWS Storage Gateway) exposes an on-premises NFS/SMB file share that durably stores files as S3 objects with local caching, enabling low-latency writes on-premises and asynchronous, near-real-time ingestion into Amazon S3 for analytics. It is purpose-built to “present a file interface backed by Amazon S3” and to “store files as objects in your S3 buckets,” so existing applications writing to a network share can transparently land data in S3 without custom scripts or job orchestration. Compared with scheduled transfers (e.g., end-of-day DataSync), S3 File Gateway continuously uploads new/changed files, better meeting the near-real-time requirement. Transfer Family (SFTP) would require custom polling and client changes, increasing operational burden. DataSync is excellent for bulk or periodic migrations/synchronizations but is not as seamless for continuous ingestion from a live file share. Therefore, updating the application to point to an S3 File Gateway share provides the simplest, performant path to near-real-time delivery into S3 for downstream analytics.

This solution is the most scalable and efficient way to handle large volumes of survey data while automating sentiment analysis:

API Gateway and SQS: The survey results are sent to API Gateway, which forwards the data to an SQS queue. SQS can handle large volumes of messages and ensures that messages are not lost.

AWS Lambda: Lambda is triggered by polling the SQS queue, where it processes the survey data.

Amazon Comprehend: Comprehend is used for sentiment analysis, providing insights into customer satisfaction.

DynamoDB with TTL: Results are stored in DynamoDB with aTime to Live (TTL)attribute set to expire after 365 days, automatically removing old data and reducing storage costs.

Option B (EC2 API): Running an API on EC2 requires more maintenance and scalability management compared to API Gateway.

Option C (S3 and Rekognition): Amazon Rekognition is for image and video analysis, not sentiment analysis.

Option D (Amazon Lex): Amazon Lex is used for building conversational interfaces, not sentiment analysis.

AWS References:

Amazon Comprehend for Sentiment Analysis

Amazon SQS

DynamoDB TTL

Amazon RDS read replicas provide a way to offload read traffic from the primary database, allowing read-intensive applications to query the replica without impacting the performance of the production (write) database. This is especially effective for workloads that involve frequently changing data but do not benefit from caching, since queries are rarely repeated.

Reference Extract from AWS Documentation / Study Guide:

"Read replicas allow you to elastically scale out beyond the capacity constraints of a single DB instance for read-heavy database workloads."

Source: AWS Certified Solutions Architect – Official Study Guide, RDS Read Replica section.

AWS PrivateLinkis the most suitable solution for providing fine-grained access control while allowing multiple VPCs, potentially across multiple accounts, to access the new application. This approach offers the following advantages:

Fine-grained control: Endpoint policies can restrict access to specific services or principals.

No need for route table updates: Unlike VPC peering or transit gateways, AWS PrivateLink does not require complex route table management.

Scalable architecture: PrivateLink scales to support traffic from multiple VPCs.

Secure connectivity: Ensures private connectivity over the AWS network, without exposing resources to the internet.

Why Other Options Are Not Ideal:

Option A:

VPC peering is not scalable when connecting multiple VPCs or accounts.

Route table management becomes complex as the number of VPCs increases.Not scalable.

Option B:

While transit gateways provide scalable VPC connectivity, they are not ideal for fine-grained access control.

Transit gateways allow connectivity but do not inherently restrict access to specific applications.Not ideal for fine-grained access control.

Option D:

Exposing the application through an ALB over the internet is not secure and does not align with the requirement to use private network resources.Security risk.

AWS References:

AWS PrivateLink:AWS Documentation - PrivateLink

AWS Networking Services Comparison:AWS Whitepaper - Networking Services

To address the high CPU utilization on the EC2 instance and the degraded performance of Amazon RDS for read requests, the solution involves two key actions: resizing the EC2 instance and leveraging Amazon RDS read replicas.

Resizing the EC2 Instance: The first step is to resize the EC2 instance to a type with more CPU capacity to handle the higher computational demands during peak usage times. This helps to alleviate the immediate pressure on the CPU.

Auto Scaling Group with a Size of 1: Although the application can only run on a single EC2 instance due to its monolithic nature, creating an Auto Scaling group with a minimum and maximum size of 1 ensures that the instance is automatically restarted or replaced in case of failure, maintaining high availability.

RDS Read Replica: Configuring an RDS read replica allows the application to offload read requests to a separate instance, thus reducing the load on the primary RDS instance. This improves the performance of read operations, which were previously bottlenecked due to the high CPU usage on the EC2 instance.

Why Not Other Options?:

Option B: Redirecting all traffic to the RDS read replica is not recommended because replicas are meant for read traffic only, not for write operations. This could lead to data consistency issues.

Option C: Increasing the RDS instance type capacity helps, but it doesn’t address the high CPU usage on the EC2 instance, nor does it provide a solution for scaling reads.

Option D: While resizing both the EC2 and RDS instances increases their capacities, it doesn’t address the specific need to offload read traffic from the primary RDS instance.

AWS References:

Amazon RDS Read Replicas- Explains how to create and use read replicas to offload read traffic from the primary database instance.

Resizing Your EC2 Instance- Guidance on resizing EC2 instances to meet workload demands.

Analysis:

The company's requirements are to migrate 5 PB of data from physical tapes to AWS within 6 months, preserve the data for 10 years, and ensure cost efficiency.AWS Storage Gateway Tape Gatewayis purpose-built for such use cases, as it seamlessly integrates with backup applications and provides virtual tape storage in Amazon S3 Glacier Deep Archive.

Why Option D is Correct:

Tape Gateway: Enables the migration of physical tapes to virtual tapes. Virtual tapes are stored in Amazon S3 and can later be archived in Amazon S3 Glacier Deep Archive for long-term storage.

Cost Efficiency: Amazon S3 Glacier Deep Archive is the lowest-cost storage class for long-term data preservation.

Operational Simplicity: Tape Gateway integrates with existing on-premises backup software, reducing the need for additional tools or manual processes.

Scalability: Can handle the migration of large datasets, such as 5 PB, within the required timeframe.

Why Other Options Are Not Ideal:

Option A:

AWS DataSync is not designed for reading data directly from physical tapes. Staging the data on local storage adds unnecessary complexity and cost.Not suitable.

Option B:

Using backup applications to write directly to S3 Glacier Deep Archive may not leverage AWS-native services optimally. Tape Gateway simplifies the workflow significantly.Less efficient.

Option C:

Snowball Edge is ideal for environments without high-bandwidth connectivity. However, the company already has a 10 Gbps Direct Connect, making Tape Gateway a better choice.Not cost-effective.

AWS References:

AWS Storage Gateway - Tape Gateway:AWS Documentation - Tape Gateway

Amazon S3 Glacier Deep Archive:AWS Documentation - Glacier Deep Archive

Amazon Macie: Detects sensitive data such as PII in S3 buckets using machine learning.

EventBridge Rule: Filters Macie findings for specific sensitive data events (e.g., SensitiveData).

SNS Notification: Provides real-time alerts to the security team for immediate action.

Amazon Macie Documentation,Amazon EventBridge Documentation

Amazon Neptune: Neptune is a fully managed graph database service that is optimized for storing and querying highly connected data. It supports both property graph and RDF graph models, making it suitable for applications that need to analyze relationships between data entities.

Neptune Streams: Neptune Streams captures changes to the graph and streams these changes to other AWS services. This is useful for applications that need to monitor and respond to changes in real-time, such as providing recommendations based on user interactions and relationships.

Least Operational Overhead: Using Neptune Streams directly with Amazon Neptune ensures that the solution is tightly integrated, reducing the need for additional components and minimizing operational overhead. This integration simplifies the architecture by eliminating the need for a separate service like Kinesis for change processing.

A. EC2 with EBS:Does not support SQL Server Always On availability groups effectively.

B. RDS Multi-AZ:Provides high availability but does not support SQL Server Always On availability groups.

C. EC2 with FSx for Windows:Best solution for SQL Server Always On as FSx provides shared storage compatible with SQL Server clustering.

D. EC2 with S3:S3 is not suitable for SQL Server storage.

Amazon Route 53 is a highly available and scalable authoritative DNS service. To move a public domain, you create a public hosted zone, import or recreate the zone records, and then update the registrar to use the Route 53 name servers assigned to the zone. Route 53 is globally distributed and designed for rapid propagation and resilience, and supports features such as health checks and routing policies. A private hosted zone (Option B) is resolvable only by VPCs that are associated with it and is not for public internet DNS. Directory Service and zone transfers (Option C) are unrelated to Route 53 public DNS hosting. Route 53 Resolver inbound endpoints (Option D) provide hybrid DNS forwarding for VPC workloads, not authoritative public hosting. Therefore, the fastest AWS-native migration path to a resilient managed DNS is to create a Route 53 public hosted zone and import the existing zone file.

In Amazon Aurora, a custom endpoint is a feature that allows you to create a load-balanced endpoint that directs traffic to a specific set of instances in your Aurora DB cluster. This is particularly useful when you want to route traffic to a subset of instances that have different configurations or when you want to isolate specific workloads (e.g., reporting queries) to certain instances.

Custom Endpoint: The correct solution is to create a custom endpoint that includes the three Aurora Replicas that the department wants to use for near-real-time reporting. This custom endpoint will distribute the reporting queries only across the three selected replicas with the specified compute and memory configurations, ensuring that these queries do not affect the rest of the DB cluster.

Other Options:

Option B (Create a three-node cluster clone): This would create a separate cluster with its own resources, but it is not necessary and could incur additional costs. Also, it doesn't leverage the existing replicas.

Option C (Use any of the instance endpoints): This would involve manually managing connections to individual instances, which is not scalable or automatic.

Option D (Use the reader endpoint): The reader endpoint would distribute the read queries across all replicas in the cluster, not just the selected three. This would not meet the requirement to limit the reporting queries to only three specific replicas.

AWS References:

Amazon Aurora Endpoints- Provides detailed information on the different types of endpoints available in Aurora, including custom endpoints.

Custom Endpoints in Amazon Aurora- Specific documentation on how to create and use custom endpoints to direct traffic to selected instances in an Aurora cluster.

Amazon DynamoDB supports Time to Live (TTL), which automatically and asynchronously deletes expired items based on a timestamp attribute. TTL is ideal for automatic data expiration with very low operational overhead.

In this scenario:

When a user requests deletion, the system can calculate an expiration timestamp one month in the future.

A Lambda function is used once per request to write or update the item’s TTL attribute to that timestamp (Option C).

DynamoDB TTL then automatically removes the item after the expiration time. Deletion typically occurs within 48 hours of the TTL timestamp, which satisfies the “within one month” requirement.

This approach offloads the actual deletion to DynamoDB and avoids building complex orchestration or periodic cleanup jobs.

Options A, B, and D add unnecessary components (EventBridge, streams, AWS Config, and Lambda-based deletion workflows) on top of TTL or custom logic, increasing operational overhead without providing additional value for the given requirement.

When using an SQS queue as an event source for AWS Lambda, the visibility timeout of the SQS queue plays a critical role in preventing duplicate message processing.

"If your Lambda function doesn't process the message and delete it from the queue within the visibility timeout period, the message becomes visible again and can be processed again by the same or another function instance."

— AWS Lambda with SQS

In this scenario, the third-party API may take up to 60 seconds to respond. Since the Lambda function is configured with a 65-second timeout, the visibility timeout of the queue must be greater than or equal to the maximum function execution time to avoid the same message being reprocessed.

Incorrect Options:

A: Memory allocation doesn’t impact duplicate message handling.

B: Timeout is already sufficient; increasing it further does not solve the core issue.

C: Delivery delay controls initial delivery delay, not reprocessing logic.

Lambda@Edge allows you to run functions at CloudFront edge locations, enabling modifications to content before it's delivered to users, including compression — which directly reduces data transfer cost.

“Lambda@Edge can be used to compress or modify your content before delivering it to end users, which reduces the amount of data transferred.”

— Lambda@Edge Use Cases

Since code modifications aren’t allowed, using Lambda@Edge is a non-invasive way to:

Compress responses.

Reduce transfer size = lower CloudFront cost.

Incorrect Options:

B: S3 Transfer Acceleration improves speed, not cost.

C: Caching doesn’t help if content is always unique (single-use).

D: Multipart uploads help with large file uploads, not transfers.

Option Ais the most automated and cost-efficient solution for exporting data to S3 for analytics.

Option Binvolves manual setup of Streams to S3.

Options C and Dintroduce complexity with EMR.

Background Jobs with Event Invocation Type:

The Event invocation type is asynchronous, meaning the Lambda function does not send an immediate result to the API Gateway and processes the request in the background. This is ideal for video encoding tasks that take time.

REST API vs. HTTP API:

REST APIs support advanced features like API keys, request validation, and throttling that HTTP APIs do not support fully.

Since the developer needs API keys and request validations, a REST API is the correct choice.

Integration with Lambda:

AWS Lambda integration is seamless with REST APIs, and using the Event invocation ensures asynchronous processing.

Incorrect Options Analysis:

Option A: HTTP API lacks full support for API keys and validation.

Option CandD: RequestResponse invocation type requires immediate responses, unsuitable for background jobs.

AWS Control Tower provides a straightforward way to set up and govern a secure, multi-account AWS environment based on AWS best practices. It automates the setup of a baseline environment, or landing zone, that includes:

Service Control Policies (SCPs): These are used to manage permissions across AWS Organizations, allowing you to set permission guardrails. SCPs can restrict access to specific AWS services and actions, helping enforce security best practices.

Multi-Factor Authentication (MFA): AWS Control Tower can enforce MFA for the root user across all accounts, enhancing security.

Centralized Governance: It offers centralized logging and monitoring, making it easier to manage and audit multiple AWS accounts.

AWS Spot best practices recommend diversifying capacity across multiple instance types and Availability Zones and using the capacity-optimized (price-capacity-optimized) allocation strategy to choose pools with the deepest capacity for higher availability. Adding a small On-Demand base in the Auto Scaling group maintains steady, uninterrupted baseline processing while keeping costs low and absorbing Spot interruptions. Option C (lowest price) increases interruption risk. Capacity Reservations (B) target On-Demand capacity guarantees and add cost, not needed for Spot-based elasticity. Option E is redundant; diversification is already achieved with (D). This combination maximizes resiliency of Spot workloads while preserving strong cost efficiency and aligns with AWS guidance for fault-tolerant, stateless applications on Spot.

AWS Secrets Manager is a fully managed service specifically designed to securely store and automatically rotate database credentials, API keys, and other secrets. Secrets Manager provides built-in integration with Amazon RDS for automatic credential rotation on a configurable schedule without requiring downtime. It also manages the secure distribution of the credentials to authorized services, such as your web servers, using IAM policies. Manual solutions (S3, files, cron jobs) do not provide the same level of automation, audit, or security.

Reference Extract from AWS Documentation / Study Guide:

"AWS Secrets Manager enables you to rotate, manage, and retrieve database credentials securely. It supports automatic rotation of secrets for supported AWS databases without requiring application downtime."

Source: AWS Certified Solutions Architect – Official Study Guide, Security and Secrets Management section.

Amazon S3 is the most cost-effective option for archiving data. Using AWS DMS to migrate to S3 in Apache Parquet format provides an optimized columnar format for analytics. By storing in S3 Glacier Flexible Retrieval, costs are minimized while maintaining compliance with retention. When queries are required, Athena can run SQL queries directly on archived data in S3 without provisioning infrastructure. Options A and B rely on maintaining RDS or EC2 instances, which increases cost and operational overhead. Option C requires full restores to EC2 before running queries, which is slow and inefficient. Therefore, D provides the lowest operational overhead and direct query capability with Athena.

AWS DataSync provides managed, incremental, parallelized transfers between EFS file systems across Regions, supporting scheduled or continuously running tasks with automatic change detection, encryption in transit, and integrity verification. You can configure two tasks in opposite directions (bi-directional) to achieve two-way synchronization with high availability using agents in each Region and EFS locations connected via VPC endpoints. Native EFS replication (B) is one-way (read-only target) and not intended for active/active two-way sync. Options A and D rely on custom rsync and cross-Region mounts or SFTP, which introduce operational overhead, latency, and fail to provide resilient, managed synchronization. DataSync minimizes operational burden while delivering fault-tolerant, scalable, cross-Region EFS sync.

Amazon Timestream: Purpose-built time series database optimized for telemetry and IoT data ingestion and analytics.

Amazon SageMaker: Provides ML capabilities for predictive maintenance workflows.

Amazon QuickSight: Efficiently generates interactive, real-time visual reports from Timestream data.

Optimized for Scale: Timestream efficiently handles large-scale telemetry data with time-series indexing and queries.

Amazon Timestream Documentation

Amazon FSx for Lustre is a high-performance parallel file system designed for machine learning and HPC that can be linked to Amazon S3 via Data Repository Associations (DRA). With DRA, you can import S3 objects as files (lazy or preloaded) and export results back to S3, providing very high throughput and low-latency POSIX access on the training cluster. This S3-native integration minimizes data loading overhead and accelerates training cycles at scale. EFS (A) is general-purpose and lower throughput per TB than Lustre. EBS (C) requires manual copy and does not scale as a shared parallel filesystem. DataSync alone (D) is a transfer tool, not a high-throughput training filesystem. FSx for Lustre with S3 DRA best satisfies scalability, throughput, and native S3 integration for rapid ML training.

To enforce that IAM users can only access Amazon RDS and no other AWS services, the recommended approach is to use a Deny statement with NotAction. This ensures that all actions are denied except RDS actions. Options A and B do not fully achieve the restriction: A only allows RDS but does not explicitly deny access to other services if another policy grants access; B’s explicit Deny for “*” would override all other permissions, including the intended RDS Allow, which would result in no access at all. Option D with permissions boundaries still allows other attached policies to grant access outside RDS. Therefore, C is the correct approach to enforce RDS-only access.

Usingcross-account IAM rolesis the most secure and scalable way to share data between AWS accounts.

Atrust relationshipallows the analytics team's account to assume the role in the main account and access the DynamoDB table directly.

Ais feasible but involves data duplication and additional costs for storing the JSON files in S3.

B and Cviolate security best practices by allowing public access to sensitive data and sharing credentials, which is highly discouraged.

AWS Documentation Reference:

Cross-Account Access with Roles

Best Practices for Amazon DynamoDB Security

Converting the existing DynamoDB table to aglobal tableprovides active-active replication and low-latency reads and writes in both Regions. DynamoDB global tables are specifically designed for multi-Region and multi-active use cases.

Option A:GSIs do not provide multi-Region replication or active-active capabilities.

Option B and D:Using DynamoDB Streams and custom replication is less operationally efficient than global tables and introduces additional complexity.

AWS Documentation References:

DynamoDB Global Tables

Lambda supports mounting an Amazon EFS file system inside your function to store larger dependencies beyond the 250 MB layer quota.

EFS automatically encrypts data in transit using TLS.

“You can configure your Lambda function to mount an Amazon EFS file system, enabling your function to access large amounts of data or large dependencies.”

“Amazon EFS automatically encrypts all data at rest and in transit.”

— Lambda with Amazon EFS

This is the least operational overhead approach.

Detailed Explanation:

A. RDS:Suitable for relational databases but does not provide native support for data lakes or row-level access.

B. Redshift:Primarily for analytics, not designed for large-scale data lake governance.

C. S3 + Lake Formation:Provides native support for data lakes with granular access control, including row-level permissions.

D. Glue Catalog + DataBrew:Focused on data preparation and metadata management, not row-level access control.

When on-premises DNS servers need to resolve private DNS names in a VPC, the correct pattern is to create a Route 53 Resolver inbound endpoint. The inbound endpoint allows DNS queries to flow from the on-premises environment into the VPC, where Route 53 can resolve VPC-specific names (such as private hosted zones or private resource records). Outbound endpoints (C) are for sending VPC DNS queries to on-premises, not the reverse. Verified Access (A) is unrelated to DNS resolution. Direct Connect (B) provides network connectivity but does not provide DNS forwarding capabilities. Therefore, option D is the correct design.

AWS Lake Formationis designed for managing fine-grained access control to data in an efficient manner:

Granular Permissions: Lake Formation allows column-level, row-level, and table-level access controls, which can precisely define access to PII data.

Integration with AWS Glue Catalog: Lake Formation natively integrates with AWS Glue for seamless data cataloging and access control.

Operational Efficiency: Centralized access control policies minimize the need for separate IAM roles or policies.

Why Other Options Are Not Ideal:

Option A:

Creating multiple IAM policies introduces complexity and lacks column-level access control.Not efficient.

Option B:

Managing multiple IAM roles for granular access is operationally complex.Not efficient.

Option D:

Creating views in Glue adds unnecessary complexity and may not provide the level of granularity that Lake Formation offers.Not the best choice.

AWS References:

AWS Lake Formation:AWS Documentation - Lake Formation

Fine-Grained Permissions with Lake Formation:AWS Documentation - Fine-Grained Permissions

Amazon SQS is the AWS-recommended service for handling decoupled, scalable, ordered, durable message ingestion with potentially large workloads. It supports payloads up to 256 KB directly and up to several MB using S3-backed large-payload extensions.

Lambda functions can process messages from SQS with automatic scaling. ECS with the Fargate launch type provides a serverless container platform for the frontend, scaling based on demand without managing servers.

SNS (Options B and D) is not a queue, does not provide durable message buffering, and is not appropriate for variable, bursty workloads that may exceed backend throughput. Lambda@Edge (Options A and D) is unsuitable for backend order processing because it runs at CloudFront edge locations with strict limitations.

Compute Savings Plans apply to EC2, AWS Fargate, and AWS Lambda usage, maximizing coverage for mixed architectures while retaining flexibility across instance families, regions, OS, and tenancy. For private connectivity, Lambda functions must be configured with VPC access to attach ENIs in the target subnets, enabling direct network access to EC2 in private subnets (no public subnets are required for intra-VPC communication). EC2 Instance Savings Plans only discount EC2 usage and are tied to a specific instance family in a region, reducing flexibility and leaving Lambda costs undiscounted. Keeping Lambda in the service VPC prevents direct access to private EC2 without VPC configuration. Thus, a 1-year Compute Savings Plan plus connecting Lambda to the private subnets minimizes total cost and meets connectivity needs.

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.

Option Cis the most secure and practical solution. Presigned URLs allow temporary, limited access to upload files to specific S3 prefixes. This ensures that artists can upload files securely without needing AWS credentials or accounts. Each artist receives a unique URL with permissions tied to the intended S3 location, and the URL can be configured to expire after a certain time, minimizing security risks.

Why Other Options Are Incorrect:

Option A:Enabling CORS allows cross-origin access but does not provide authentication or authorization for uploads. This does not secure the uploads or restrict access to specific artists.

Option B:Turning off block public access and sharing the bucket URL exposes the bucket to potential misuse and unauthorized uploads. This approach is highly insecure.

Option D:While a web interface might work, it introduces additional complexity and potential security risks by exposing upload functionality through a public-facing application.

AWS Documentation References:

Using Amazon S3 Presigned URLs

AWS Best Practices for Secure S3 Access

Correct Approach:

AWS Security Groups:

Security groups operate at the instance level, making them the ideal tool for controlling access to specific resources such as an Amazon RDS database.

By default, security groups deny all incoming traffic. You can allow access by explicitly specifying another security group.

Associating an RDS database security group with the EC2 instances' security group ensures only the specified EC2 instances can access the RDS database.

Incorrect Options Analysis:

Option A: Using CIDR blocks for IP-based access is less secure and more difficult to manage. Additionally, Auto Scaling groups dynamically allocate IP addresses, making this approach impractical.

Option B: Network ACLs (NACLs) operate at the subnet level and are stateless. While NACLs can deny or allow traffic, they are not suited to application-specific access control.

Option D: Similar to Option B, using a NACL with CIDR ranges for EC2 IPs is difficult to manage and not application-specific.

To improve the performance of the primary RDS PostgreSQL database during business hours and reduce the load, the best solution is to create aread replicain the same region (us-east-1). This will offload the read-heavy operations (like generating reports) to the replica, reducing the burden on the primary instance, which improves overall performance. Additionally, read replicas provide near real-time replication, making them ideal for real-time reporting use cases.

Option A (cross-Region read replica): This adds unnecessary latency for real-time reporting and increased costs due to cross-region data transfer.

Option B (Multi-AZ): Multi-AZ deployments are for high availability and disaster recovery but won’t offload the read traffic, as the standby database cannot serve read requests.

Option C (AWS DMS replication): This adds complexity and is not as cost-effective as using an RDS read replica for the same region.

AWS References:

Amazon RDS Read Replicas

Amazon RDS Performance Best Practices

AWS recommends multi-Region active-active architectures for applications requiring high availability, automatic failover, and disaster recovery. Route 53 latency-based routing directs users to the Region providing the lowest latency and automatically shifts traffic if Regional endpoints become unhealthy.

Combined with Application Load Balancers and EC2-based microservices deployed in multiple Regions, this architecture delivers fault tolerance, multi-Region resiliency, and automatic recovery.

Option D provides high availability but does not inherently provide multi-Region failover routing without additional configuration. Option B is single-Region. Option A is not resilient.

=====================================================

Detailed Explanation:

A. EventBridge Rule:Detects modifications to CloudFront distributions in real time and triggers the Lambda function for further action.

B. ALB + Config:Focuses on ALB security violations, not relevant for CloudFront logging changes.

C. Lambda + SNS:Provides real-time notifications about changes in logging configuration.

D. GuardDuty:Focuses on threat detection, not logging configuration changes.

E. API Gateway + WAF:Unrelated to CloudFront logging changes.

Option Ais the simplest solution, using DynamoDB Streams and Lambda for real-time ingestion into S3.

Options B, C, and Dadd unnecessary complexity with Data Firehose or Kinesis.

Amazon FSx for ONTAP supports both NFS and SMB protocols and includes automated tiering between SSD and capacity pool storage, optimizing cost and performance. It is ideal for mixed operating systems and varied access patterns with minimal administrative overhead.

Amazon S3 Storage Lens:

S3 Storage Lens provides organization-wide visibility into object storage usage and activity trends.

It can generate metrics and insights about your S3 buckets, including versioning status.

Configuration:

Enable S3 Storage Lens at the organization level.

Configure the dashboard to include the versioning status metric.

Identify Non-Versioned Buckets:

Use the S3 Storage Lens dashboard to filter and identify buckets that do not have versioning enabled.

Storage Lens provides detailed insights and reports which can be used to enforce compliance and manage storage effectively.

Operational Efficiency: Using S3 Storage Lens provides a centralized, easy-to-use interface for monitoring bucket configurations across multiple Regions and accounts, reducing the need for custom scripts or manual checks.

According to the AWS Well-Architected Framework – Security Pillar and the AWS Identity and Access Management (IAM) User Guide, the root user account in an AWS account is extremely powerful and should be protected with strict security measures.

From AWS documentation:

“We recommend that you not use the root user for everyday tasks, even administrative ones. Instead, create IAM users and grant them only the permissions they need. To help protect your AWS account, enable multi-factor authentication (MFA) for the root user.”

(Source: AWS Identity and Access Management User Guide – Securing the Root User)

The correct and recommended action is to create IAM users with specific permissions for daily operations and enable MFA on the root user to provide an additional layer of security. The root user cannot be disabled, so Option A is technically incorrect. AWS also explicitly advises against using root access keys (Option C) or sharing root credentials (Option D), both of which violate the principle of least privilege.

Best practices summarized from AWS official documentation:

Do not use root user for routine tasks

Enable MFA for root user immediately

Create individual IAM users and assign least privilege

Avoid creating or using root user access keys

These recommendations are foundational to securing any new AWS account and are consistently emphasized in the AWS Certified Solutions Architect – Official Study Guide and the AWS Security Best Practices whitepaper.

Explanation (AWS Docs):

DynamoDB has a built-in feature called Time to Live (TTL) which automatically deletes expired items without manual intervention. This requires adding a timestamp attribute and setting a TTL on the table. This is the lowest operational overhead approach.

“You can use DynamoDB TTL to automatically delete items after a specified time, reducing storage costs and administrative overhead.”

— DynamoDB TTL

The most scalable and managed solution for streaming ingestion, real-time transformation, and delivery to Amazon S3 is Amazon Kinesis Data Streams, Amazon Managed Service for Apache Flink, and Amazon Kinesis Data Firehose.

From AWS Documentation:

“Amazon Kinesis Data Streams enables real-time processing of streaming data at massive scale. With Apache Flink on Kinesis Data Analytics, you can process data streams in near real-time, then use Amazon Kinesis Data Firehose to reliably deliver that data to S3.”

(Source: Amazon Kinesis Developer Guide)

Why A is correct:

Fully managed: All services involved are serverless and managed.

Real-time ingestion: Kinesis Data Streams supports sub-second latency and can handle high-throughput workloads like 100,000+ devices.

Near real-time processing: Apache Flink is designed for continuous stream processing with complex event handling.

Efficient delivery: Kinesis Firehose delivers processed data directly to S3 with retry and backup capability.

Why other options are incorrect:

Option B: SQS is not optimized for real-time streaming at high volume.

Option C: EC2 + Kafka + EMR adds high operational overhead and cost.

Option D: EventBridge is event-driven, not designed for high-throughput streaming; AWS Batch is unsuitable for near real-time processing.

AWS Config is a service that enables you to assess, audit, and evaluate the configurations of your AWS resources. By creating a Config rule, you can automatically check whether your Amazon EBS volumes are encrypted and flag those that are not, with minimal cost and configuration effort.

AWS Config Rule: AWS Config provides managed rules that you can use to automatically check the compliance of your resources against predefined or custom criteria. In this case, you wouldcreate a rule to evaluate EBS volumes and determine if they are encrypted. If a volume is not encrypted, the rule will flag it, allowing you to take corrective action.

Operational Overhead: This approach significantly reduces operational overhead because once the rule is in place, it continuously monitors your EBS volumes for compliance, and there’s no need for manual checks or custom scripting.

Why Not Other Options?:

Option A (Lambda with API calls and EventBridge): While this can work, it involves writing and maintaining custom code, which increases operational overhead compared to using a managed AWS Config rule.

Option B (API calls on Fargate): Running API calls on Fargate is more complex and costly compared to using AWS Config, which provides a simpler, managed solution.

Option C (IAM policy with Cost Explorer): This option does not directly enforce encryption compliance and involves manual intervention, making it less efficient and more prone to errors.

AWS References:

AWS Config Rules- Overview of AWS Config rules and how they can be used to evaluate resource configurations.

Amazon EBS Encryption- Information on how to manage and enforce encryption for EBS volumes.

The question focuses on minimizing costs while serving static content to users in the US and Europe.

Option Auses a single S3 bucket and configures CloudFront to limit edge locations, reducing costs by using fewer edge locations while still improving performance.

Option Bmaximizes edge locations, which increases costs unnecessarily.

Options C and Dinvolve storing data in multiple regions, which increases storage and operational costs.Thus, Option A is the most cost-effective solution.

To optimize storage costs, migrating data from Amazon EFS to Amazon S3 with the Intelligent-Tiering storage class is a cost-effective solution.

Amazon S3 Intelligent-Tiering: This storage class automatically moves data between frequent, infrequent, and archive access tiers based on access patterns, reducing storage costs without impacting performance.

Cost Savings: By leveraging Intelligent-Tiering, the company can achieve significant cost savings, especially for data with unpredictable access patterns.

Application Update: The application must be updated to interact with Amazon S3 APIs for storing and retrieving files, ensuring seamless integration with the new storage solution.

This approach provides a scalable, durable, and cost-effective storage solution, aligning with the company's optimization goals.

Amazon EBS Snapshots Recycle Bin enables you to specify retention rules for EBS snapshots based on tags. When snapshots are deleted, they are retained in the Recycle Bin for a specified duration, preventing accidental deletion. Tag-level rules allow selective protection without changing IAM roles or user permissions.

A. API Gateway + DynamoDB:Provides high scalability, low latency, and seamless integration with Amazon Comprehend for NLP tasks.

B. HTTP API + Translate + ElastiCache:Translate is not relevant for NLP tasks like sentiment analysis or entity recognition. ElastiCache is unsuitable for permanent storage.

C. SQS + EC2 + RDS:Increases complexity and operational overhead. RDS may not scale effectively for high concurrent loads.

D. WebSocket API + Textract:Textract is irrelevant for NLP tasks. WebSocket API is not the optimal choice for this use case.

AmazonKinesis Data Streamsis the best choice for this scenario:

Message throughput: Kinesis Data Streams supports high throughput with enhanced fan-out and dedicated throughput for consumers.

Large message size: Supports message sizes up to 1 MB, meeting the 500 KB requirement.

Message retention: Data streams can retain messages for up to 365 days.

Strict ordering: Guarantees message ordering within shards.

Why Other Options Are Not Ideal:

Option B:

While SQS FIFO supports strict ordering, SNS topics do not. SNS also does not natively support message retention or strict ordering across consumers.Does not meet requirements.

Option C:

EventBridge does not provide strict ordering guarantees or message retention beyond 24 hours.Does not meet requirements.

Option D:

SNS topics with Data Firehose are not designed for use cases requiring strict ordering or long message retention.Does not meet requirements.

AWS References:

Amazon Kinesis Data Streams:AWS Documentation - Kinesis Data Streams

AWS Messaging Services Comparison:AWS Documentation - Messaging Services

Amazon GuardDuty includes RDS Protection that “monitors and profiles access to your Amazon Aurora and Amazon RDS databases” to detect threats such as suspicious login attempts, brute-force activity, and anomalous authentication patterns. GuardDuty can be enabled organization-wide in AWS Organizations with a delegated administrator to centralize findings for all member accounts, minimizing operational overhead. Findings include context like source IP, user, and DB instance, and integrate with Amazon EventBridge for alerting and automated response. SCPs (A) enforce or deny API permissions but do not provide detection/analytics. Exporting general logs (C) requires building and maintaining custom parsing/analytics pipelines. CloudTrail (D) records AWS control-plane API calls and does not log database-level login attempts. Therefore, enabling GuardDuty RDS Protection across the org provides the most operationally efficient, managed detection of abnormal failed and incomplete login attempts.

TheAWS WAF Bot Control managed ruleis designed to automatically detect and mitigate bot traffic. This feature is particularly useful for addressing malicious traffic and conserving compute resources by filtering unnecessary requests at the ALB level.

Option A:Blocking IP addresses manually introduces significant operational overhead and is not scalable against dynamic, worldwide malicious traffic.

Option C:AWS Shield provides DDoS protection, but the scenario does not describe a DDoS attack. WAF is better suited for managing application-layer threats like bot traffic.

Option D:The AWS WAF IP reputation rule helps block traffic from known bad IPs but may not address bot traffic effectively.

AWS Documentation References:

AWS WAF Bot Control

AWS WAF Managed Rules

This solution is the most suitable for running cron jobs on AWS with minimal refactoring, while also supporting the possibility of running jobs in response to future events.

Container Image for Cron Jobs: By containerizing the cron jobs, you can package the environment and dependencies required to run the jobs, ensuring consistency and ease of deployment across different environments.

Amazon EventBridge Scheduler: EventBridge Scheduler allows you to create a recurring schedule that can trigger tasks (like running your cron jobs) at specific times or intervals. It provides fine-grained control over scheduling and integrates seamlessly with AWS services.

AWS Fargate: Fargate is a serverless compute engine for containers that removes the need to manage EC2 instances. It allows you to run containers without worrying about the underlying infrastructure. Fargate is ideal for running jobs that can vary in duration, like cron jobs, as it scales automatically based on the task's requirements.

Why Not Other Options?:

Option A (Lambda): While AWS Lambda could handle short-running cron jobs, it has limitations in terms of execution duration (maximum of 15 minutes) and might not be suitable for jobs that run up to 20 minutes.

Option B (AWS Batch on ECS): AWS Batch is more suitable for batch processing and workloads that require complex job dependencies or orchestration, which might be more than what is needed for simple cron jobs.

Option D (Step Functions with Wait State): While Step Functions provide orchestration capabilities, this approach would introduce unnecessary complexity and overhead compared to the straightforward scheduling with EventBridge and running on Fargate.

AWS References:

Amazon EventBridge Scheduler- Details on how to schedule tasks using Amazon EventBridge Scheduler.

AWS Fargate- Information on how to run containers in a serverless manner using AWS Fargate.

Explanation (AWS Docs):

DynamoDB Accelerator (DAX) is a fully managed, in-memory cache specifically for DynamoDB. It reduces read load and latency without requiring code changes (only SDK config). This is the least development effort.

“Amazon DynamoDB Accelerator (DAX) is a fully managed, highly available in-memory cache for DynamoDB that delivers microsecond read performance and requires minimal application changes.”

— Amazon DAX

Amazon Aurora MySQL provides:

Continuous, incremental backups to Amazon S3 with point-in-time recovery (PITR), allowing recovery to any point within the retention window (typically up to 35 days). This easily achieves an RPO of less than 5 hours, often down to seconds.

Support for database auditing parameters so audit logs can be retained and managed (for example, in database logs or external log services) to meet the 7-day audit requirement.

Auto scaling (via read replicas, Aurora Serverless v2, or capacity management) to handle variable read/write demand throughout the year with minimal operational overhead.

Why others are less suitable:

A: DynamoDB is NoSQL and does not directly satisfy typical relational database + SQL audit requirements; Streams also only retain 24 hours, not 7 days, and on-demand backups do not inherently give an RPO < 5 hours without frequent scheduling.

B: Amazon Redshift is a data warehouse, not a primary transactional application database.

C: Snapshots every 5 hours give an RPO of up to 5 hours, not less than 5 hours, and rely on discrete snapshot points rather than continuous PITR.

To protect against a Regional failure, the application must be deployed in multiple Regions. Amazon Route 53 DNS failover with health checks allows traffic to be automatically routed to a healthy Region when the primary becomes unavailable, meeting high availability and disaster recovery requirements.

This solution is the most cost-effective and meets the RPO and RTO requirements of 24 hours.

Automatic Snapshots: Amazon RDS automatically creates snapshots of your DB instance at regular intervals. By copying these snapshots to another AWS Region every 24 hours, you ensure that you have a backup available in a different geographic location, providing disaster recovery capability.

RPO and RTO: Since the company’s RPO and RTO are both 24 hours, copying snapshots daily to another Region is sufficient. In the event of a disaster, you can restore the DB instance from the most recent snapshot in the target Region.

Why Not Other Options?:

Option A (Cross-Region Read Replica): This could provide a faster recovery time but is more costly due to the ongoing replication and resource usage in another Region.

Option B (DMS Cross-Region Replication): While effective for continuous replication, it introduces complexity and cost that isn’t necessary given the 24-hour RPO/RTO.

Option C (Cross-Region Native Backup Copy): This involves more manual steps and doesn’t offer as straightforward a solution as automated snapshot copying.

AWS References:

Amazon RDS Automated Backups and Snapshots- Details on automated backups and snapshots in RDS.

Copying an Amazon RDS DB Snapshot- How to copy DB snapshots to another Region.

Option Auses an IAM role attached to the EC2 instance profile, enabling secure and automated access to Secrets Manager. This is the recommended approach.

Option Buses IAM users, which is less secure and harder to manage.

Option Cis not practical for accessing secrets programmatically.

Option Dviolates best practices by granting direct access to the EC2 instance.

Using S3 event notifications to trigger AWS Lambda for file processing is a cost-effective and serverless solution. Lambda scales automatically with upload volume, and processing each file takes less than 5 seconds, fitting within Lambda's execution time.

Option A:AWS AppSync is designed for GraphQL APIs and is not suitable for file processing.

Option C:Kinesis is overkill and more expensive for this use case.

Option D:Running an EC2 instance incurs ongoing costs and is less flexible compared to Lambda.

AWS Documentation References:

Amazon S3 Event Notifications

AWS Lambda Overview

AWS Global Accelerator reduces latency by directing users to the optimal Regional endpoint based on global network health and proximity. Amazon CloudFront caches static and dynamic content at edge locations for ultra-low latency access worldwide, improving performance and reducing server load.

Amazon EMR allows the creation of security configurations to specify settings for encrypting data at rest, data in transit, or both. These configurations can be applied to clusters to ensure that data stored in Amazon S3, local disks, and data moving between nodes is encrypted.

By creating and applying an EMR security configuration, the company can ensure that all data processing complies with encryption requirements for sensitive patient data.

Amazon EFS provides a shared, fully managed, POSIX-compliant file system that can be mounted by all EC2 instances. Any update made to the file system is immediately visible to all instances, ensuring every new instance has the latest product manuals without delay.

EFS automatically scales storage and throughput, meeting high-demand conditions with no application changes required.

S3 requires instances to download files locally, causing delay and stale data issues (Options B and D). Instance store volumes (Option A) are ephemeral and not shared, making them unsuitable for consistent data distribution.

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AWS recommends using Amazon ElastiCache as an in-memory caching layer in front of relational databases such as Amazon RDS to offload read traffic and significantly improve performance for read-heavy workloads. ElastiCache (Redis OSS) provides microsecond latency and can cache the results of frequent or expensive queries without requiring any change to the underlying database schema or engine. This directly addresses the requirement to improve performance without changing the database structure and with minimal operational overhead, because ElastiCache is a fully managed service (patching, failure detection, replacement, etc., are handled by AWS).

Option A (DynamoDB) would require a full data migration and application changes, including schema and query rewrites.

Option C (Memcached on EC2) introduces additional management overhead for EC2 instances (scaling, patching, HA).

Option D (DAX) is a caching layer only for DynamoDB and cannot be used directly with Amazon RDS.

The best practice for secure access control in AWS is to use IAM roles with least-privilege policies, granting only the permissions necessary to perform required tasks. Assigning roles individually ensures that developers cannot overstep their intended access boundaries.

Sharing credentials or using permanent access keys increases the risk of security breaches. Cognito is primarily intended for managing user access to applications, not AWS infrastructure. Thus, Option B best meets security and access control requirements.

To allocate costs based on team ownership, AWS recommends tagging resources using cost allocation tags. Activating the “owner” tag as a cost allocation tag allows AWS Cost Explorer to categorize and group spending. Additionally, filtering for Amazon ECS services enables the visibility into service-specific usage. This approach is both scalable and operationally efficient.

IAM Roles for Service Accounts (IRSA): IRSA allows you to associate an IAM role with a Kubernetes service account. This enables pods to assume the IAM role and access AWS resources securely.

Annotating Service Accounts: By annotating Kubernetes service accounts with the ARN of the IAM role, you establish the association required for IRSA.

OIDC Identity Provider: EKS clusters use OpenID Connect (OIDC) to authenticate service accounts. Setting up a trust relationship between the IAM role and the OIDC provider allows the Kubernetes service account to assume the IAM role.

Private subnets require outbound internet access to download updates, but they must not have public IPs or direct inbound access.

The recommended AWS solution is to create a NAT gateway in a public subnet. Private subnet route tables are updated to route internet-bound traffic (0.0.0.0/0) to the NAT gateway. The NAT gateway then uses the internet gateway attached to the VPC to communicate with the internet.

Option B (NAT instances) is an older approach and less scalable/maintainable than NAT gateways. Option C (egress-only internet gateway) is for IPv6 outbound-only traffic, not IPv4. Option D is invalid because NAT gateways must be deployed in public subnets.

A. ElastiCache:Provides in-memory caching, not suitable for persistent, scalable databases.

B. DynamoDB Streams + Lambda:Manages replication manually, increasing latency and operational complexity.

C. Aurora Global Database:Provides high availability but does not support active-active configuration.

D. DynamoDB Global Tables:Provides active-active configuration and sub-second RPO.

Why Option C is Correct:

S3 Access Points: Provide scalable management of access to large datasets with specific permissions for individual prefixes.

Dynamic Prefixes: Access points simplify managing access to a growing number of prefixes without relying solely on a single bucket policy.

Fine-Grained Control: Resource-based permissions on access points enforce prefix-level isolation effectively.

Why Other Options Are Not Ideal:

Option A: Using deny/allow bucket policies introduces complexity and is less scalable for dynamic prefixes.

Option B: Encryption ensures data security but does not address access management.

Option D: Pre-signed URLs are temporary and not suitable for managing access at scale.

AWS References:

Amazon S3 Access Points:AWS Documentation - S3 Access Points

Why Option B is Correct:

AWS WAF: Provides a simple way to create geographic match rules to block or allow traffic based on country IP ranges.

Least Operational Overhead: Attaching the WAF rule to the ALB ensures centralized control without modifying ACLs or instance firewalls.

Why Other Options Are Not Ideal:

Option A: Network ACLs operate at the subnet level and can become complex to manage for dynamic or evolving IP ranges.

Option C: Managing IP-based rules in security groups and ACLs lacks scalability and does not provide country-based filtering.

Option D: Configuring host-based firewalls increases operational overhead and does not leverage AWS-managed solutions.

AWS References:

AWS WAF Geomatch:AWS Documentation - WAF Geomatch

Amazon Aurora Serverless v2 is ideal for applications with unpredictable or intermittent workloads. It automatically scales capacity up or down based on demand, significantly reducing costs. It supports automated backups to Amazon S3, making it suitable and cost-effective for new applications with variable traffic.

Serving static content from Amazon S3 is highly cost-effective and scalable. By fronting the S3 bucket with Amazon CloudFront, you also enable global caching, reduced latency, and even lower costs by reducing direct S3 access. There is no need for EC2 or ALB, and no need to manage servers, further lowering operational burden and expenses. This pattern is the recommended AWS architecture for serving static web content.

Reference Extract from AWS Documentation / Study Guide:

"Hosting static websites on Amazon S3 with Amazon CloudFront reduces infrastructure costs and improves performance for global users by caching content at edge locations."

Source: AWS Certified Solutions Architect – Official Study Guide, S3 and CloudFront section.

A. Aurora MySQL:Handles OLTP workloads efficiently with built-in replication and auto-scaling capabilities.

B. EC2 with MySQL:Requires heavy manual maintenance and does not scale seamlessly.

C. RDS for MySQL:Limited in auto-scaling compared to Aurora.

D. Redshift:Primarily for OLAP, not suitable for OLTP workloads.

Option Ais the best solution as it leveragesAWS Lambdafor serverless, scalable, and highly available processing and enrichment of clickstream data. Lambda can process the data in real-time, join it with the Aurora database data, and write the enriched results to Amazon S3. FromS3,Amazon Redshift Spectrumcan directly query the enriched data without needing to load the data into Redshift, enabling cost efficiency and high availability.

Why Other Options Are Incorrect:

Option B:EC2 Spot Instances are not guaranteed to be highly available, as Spot Instances can be interrupted at any time. This does not align with the requirement for high availability.

Option C:While ECS with AWS Fargate provides scalability, using EC2 for the COPY command introduces operational overhead and compromises high availability.

Option D:Kinesis Data Firehose and Athena are suitable for querying raw data, but they do not directly support enriching the data by joining with Aurora. This solution fails to meet the requirement for data enrichment.

Key AWS Features Used:

AWS Lambda:Real-time serverless processing with integration capabilities for Aurora and S3.

Amazon S3:Cost-effective storage for enriched data.

Amazon Redshift Spectrum:Direct querying of data stored in S3 without loading it into Redshift.

AWS Documentation References:

AWS Lambda Function Overview

Amazon Redshift Spectrum

Processing Streaming Data with Kinesis Data Streams

Amazon Aurora Serverless is a cost-effective, on-demand, autoscaling configuration for Amazon Aurora. It automatically adjusts the database's capacity based on the current demand, which is ideal for workloads with variable and unpredictable usage patterns. Since the application is expected to be read-heavy with occasional writes and steady growth, Aurora Serverless can provide the necessary performance without requiring the management of database instances.

Cost-Optimization: Aurora Serverless only charges for the database capacity you use, making it a more cost-effective solution compared to always running provisioned database instances, especially for workloads with fluctuating demand.

Scalability: It automatically scales database capacity up or down based on actual usage, ensuring that you always have the right amount of resources available.

Performance: Aurora Serverless is built on the same underlying storage as Amazon Aurora, providing high performance and availability.

Why Not Other Options?:

Option A (RDS with Provisioned IOPS SSD): While Provisioned IOPS SSD ensures consistent performance, it is generally more expensive and less flexible compared to the autoscaling nature of Aurora Serverless.

Option C (DynamoDB with On-Demand Capacity): DynamoDB is a NoSQL database and may not be the best fit for applications requiring relational database features.

Option D (RDS with Magnetic Storage and Read Replicas): Magnetic storage is outdated and generally slower. While read replicas help with read-heavy workloads, the overall performance might not be optimal, and magnetic storage doesn’t provide the necessary performance.

AWS References:

Amazon Aurora Serverless- Information on how Aurora Serverless works and its use cases.

Amazon Aurora Pricing- Details on the cost-effectiveness of Aurora Serverless.

Since the workload is interruptible and can resume after restarts, Amazon EC2 Spot Instances are the most cost-effective option, offering savings of up to 90% compared to On-Demand. Running the batch workload on AWS Batch with Spot Instances allows automatic job queue management, interruption handling, and scheduling. Option A and C reduce cost but still rely on reserved or committed pricing for On-Demand capacity. Option B (Capacity Reservations) increases cost instead of reducing it. Therefore, the most cost-optimized solution is D — AWS Batch with EC2 Spot Instances.

AWS Outposts brings native AWS services (including Amazon EMR) on-premises, ideal when data residency or latency constraints require local processing.

You benefit from AWS’s managed services while meeting the requirement to keep data processing local.

Why Option B is Correct:

HTTP Proxy Integration: Passes XML requests directly to the application, which already supports XML.

JSON Conversion: An AWS Lambda function converts JSON requests to XML and calls the application.

API Gateway: Acts as a front end to handle JSON requests and integrates seamlessly with Lambda for the transformation process.

Why Other Options Are Not Ideal:

Option A: Suggests using API Gateway mappings to convert JSON to XML. API Gateway mapping templates are limited in functionality and are not ideal for complex transformations.

Option C and D: Use HTTP custom integration unnecessarily, which adds complexity without additional benefits.

AWS References:

Amazon API Gateway Integration:AWS Documentation - API Gateway Integration

AWS Lambda:AWS Documentation - Lambda

Amazon RDS Proxy helps manage and pool database connections from serverless compute like AWS Lambda, significantly reducing the stress on the database during unpredictable traffic surges. It improves scalability and resiliency by efficiently managing connections, protecting the database from being overwhelmed, and enabling failover handling.

Option A is the most cost-effective and operationally efficient approach to handling unpredictable surges and improving resilience without requiring major application changes.

Option B involves a migration to DynamoDB, which is a significant architectural change and costlier initially. Option C is manual connection cleanup, insufficient for unpredictable surges. Option D increases resources but does not solve connection storm problems efficiently and is more costly.

AWS Shield Advanced provides advanced DDoS protection for AWS workloads, including EC2, CloudFront, and RDS. When integrated with CloudFront, Shield Advanced offers comprehensive detection and mitigation against large and sophisticated DDoS attacks, along with 24x7 access to the AWS DDoS Response Team (DRT). AWS WAF provides application-level protection, but for complete DDoS mitigation, Shield Advanced is the recommended solution.

Reference Extract from AWS Documentation / Study Guide:

"AWS Shield Advanced provides expanded DDoS attack protection for applications running on AWS. It offers always-on detection and automatic inline mitigations that minimize application downtime and latency."

Source: AWS Certified Solutions Architect – Official Study Guide, Security and DDoS Protection section.

AWS Backup is a fully managed backup service that can create backup plans for EC2 instances, including both instance configurations and attached EBS volumes, with scheduled and cross-Region copy capabilities. By adding the EC2 instances to the resource assignment in the backup plan, AWS Backup automatically backs up all configurations and attached EBS volumes, and can copy backups to a secondary Region for disaster recovery, providing the highest operational efficiency with the least manual effort.

AWS Documentation Extract:

“AWS Backup provides fully managed backup for EC2 instances and attached EBS volumes, with scheduling, retention, and cross-Region copy built in. By adding the EC2 instance as a resource, the backup includes both configuration and attached volumes.”

(Source: AWS Backup documentation)

A, D: Custom Lambda scripts increase operational overhead and are not as integrated or robust as AWS Backup.

C: Assigning only EBS volumes does not include the EC2 instance configuration, which is needed for full recovery.

Aurora blue/green deployments are specifically designed for:

Safely testing schema changes and database upgrades in an isolated environment (green) without impacting production (blue).

Performing a fast, low-downtime switchover once testing is complete and validated.

In this pattern:

The blue environment is the current production database.

The green environment is a synchronized copy used for testing changes.

You apply schema changes to the green environment, run tests, and when ready, perform a managed switchover that minimizes downtime and risk.

Why others are not ideal:

A: A separate staging cluster allows testing but does not provide automated, low-downtime synchronization and switchover.

B: Aurora read replicas are for read scaling; schema changes on replicas are not supported in the way described, and promotion alone doesn’t solve controlled testing and replication of changes.

D: Moving to DynamoDB changes database engines and data models entirely, and does not match the requirement to keep using Aurora MySQL.

Why Option A is Correct:

ElastiCache for Redis: Provides persistent, scalable caching for in-progress transactions and SQL queries. Redis supports data durability and advanced features, making it suitable for transactional workloads.

Integration with Aurora: Easily integrates with the Aurora cluster to improve query performance.

Why Other Options Are Not Ideal:

Option B: CloudFront and S3 are unsuitable for transactional caching. EC2 instance store volumes are ephemeral and lack persistence.

Option C: Memcached does not offer persistence or advanced transactional support, unlike Redis.

Option D: Combining Redis with EC2 instance store is unnecessary; Redis alone meets all caching requirements.

AWS References:

Amazon ElastiCache:AWS Documentation - ElastiCache

Amazon S3 Intelligent-Tiering is designed for unknown or unpredictable access patterns, automatically moving objects to the most cost-effective tier without performance impact.

It is ideal when you do not know object size or access frequency.

S3 Standard (Option B) works but costs more.

S3 One Zone-IA and Glacier Deep Archive (Options D and A) are not appropriate because data is frequently accessed for processing and persists only 24 hours.

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Amazon CloudFront is a highly cost-effective CDN that caches content like images and videos at edge locations globally. This reduces latency and the load on the origin S3 bucket. It is ideal for static content that is accessed by many users.

AWS Batch supports Windows-based jobs and automates provisioning and scaling of compute environments. Paired with AWS Fargate, it removes the need to manage infrastructure. This solution requires the least operational overhead and is cloud-native, providing flexibility and scalability.

To decouple the monolith and enhance scalability, AWS best practice is to introduce an asynchronous message queue, such as Amazon SQS, between the web/API tier and the order-processing logic.

AWS Lambda functions consuming from the SQS queue provide serverless, auto-scaling processing without managing servers.

To track and reprocess failed orders, SQS supports dead-letter queues (DLQs). Messages that cannot be processed successfully after a configurable number of attempts are automatically moved to the DLQ, where operations teams or automated processes can inspect and reprocess them.

Why others are not correct:

B: ECS tasks can consume an SQS queue, but this requires managing container infrastructure and does not inherently provide as simple reprocessing/visibility as combining Lambda with a DLQ. Visibility timeout is not a tracking or archival mechanism.

C: Kinesis is a streaming service designed for ordered event streams, not primarily for order-queue semantics and DLQs; SQS is simpler and purpose-built for this pattern.

D: Long polling reduces empty responses and API calls but does nothing for tracking or reprocessing failed messages; without a DLQ, failed orders are harder to manage

Memory Optimized Instances: These instances are designed to deliver fast performance for workloads that process large data sets in memory. They are ideal for high-performance databases like SAP and applications with high memory utilization.

High Memory Utilization: Both the SAP application and the SQL Server database have high memory demands as per the on-premises performance data. Memory optimized instances provide the necessary memory capacity and performance.

Instance Types:

For the SAP application, using a memory optimized instance ensures the application has sufficient memory to handle the high workload efficiently.

For the SQL Server database, memory optimized instances ensure optimal database performance with high memory throughput.

Operational Efficiency: Using the same instance family for both the application and the database simplifies management and ensures both components meet performance requirements.

Amazon Cognitoprovides scalable, serverless authentication, andLambda@Edgeis used for authorization, providing low-latency access control at the edge.Amazon CloudFrontserves the web application globally with reduced latency and ensures secure access for users around the world. This solution minimizes operational overhead while providing scalability and security.

Option B (Directory Service): Directory Service is more suitable for enterprise use cases involving Active Directory, not for web-based applications.

Option C (S3 Transfer Acceleration): S3 Transfer Acceleration helps with file transfers but does not provide authorization features.

Option D (Elastic Beanstalk): Elastic Beanstalk adds unnecessary overhead when CloudFront can handle global delivery efficiently.

AWS References:

Amazon Cognito

Lambda@Edge

The SELECT INTO OUTFILE S3 feature allows you to export Amazon Aurora MySQL data directly to Amazon S3 with minimal operational overhead. This method is efficient and cost-effective for archiving historical data.

You can configure S3 Lifecycle rules to transition the exported data to lower-cost storage (e.g., S3 Glacier or S3 Standard-IA) and eventually delete it after 5 years.

No need for additional ETL tools like Glue or DataBrew unless complex transformations are required.

Amazon Neptune is a fully managed graph database service optimized for storing and navigating complex many-to-many relationships like social graphs or network topologies.

It supports Gremlin and openCypher queries that allow efficient traversal of connections even multiple levels deep. SQL JOINs (Athena or RDS) are inefficient for deep relationship queries due to exponential complexity.

QuickSight is used for data visualization, not graph traversal.

This architecture uses ALB for routing, Auto Scaling for elasticity, SQS to buffer unprocessed orders and decouple services, and RDS Multi-AZ for high availability and durability of transactional data. This ensures resilience and fault tolerance even during traffic spikes.

Amazon Managed Streaming for Apache Kafka (Amazon MSK) is a fully managed service that makes it easy to build and run applications that use Apache Kafka to process streaming data. By using Amazon ECS with the AWS Fargate launch type, you can run containers without managing servers or clusters. This combination reduces operational overhead and provides scalability.

AWS provides EBS Block Public Access at the AWS Organizations level, which, when enabled, prevents EBS snapshots from being shared publicly across all member accounts. This is an organization-wide control that requires minimal configuration and no ongoing monitoring to prevent public sharing.

This directly satisfies the requirement:

Covers all accounts managed by Organizations.

Explicitly prevents public snapshot sharing.

Has the least operational overhead because it is a single centralized control.

AWS Config (Option A) only monitors and alerts, but does not prevent public sharing.

An IAM policy in the root account (Option C) is harder to enforce consistently across all accounts and may not cover all permission paths.

CloudTrail (Option D) only logs events and does not prevent public access.

Using Amazon CloudFront in front of an ALB in a single region is a cost-effective way to deliver content with low latency across the globe. CloudFront caches content closer to the users, reducing the load on backend servers and minimizing data transfer costs by serving cached content from edge locations.

Compared to Global Accelerator, CloudFront is significantly more cost-optimized for static and dynamic content delivery. Multi-region deployments increase infrastructure and transfer costs, which violates the optimization goal. Therefore, option A provides the best mix of performance and cost efficiency.

Amazon Managed Service for Apache Flink (formerly Kinesis Data Analytics) is a fully managed, serverless service for real-time processing of streaming data. You can consume data from Kinesis Data Streams, perform anomaly detection, and then output the results to another Kinesis stream. This approach is loosely coupled, fully managed, and does not require modifying the application code.

AWS Documentation Extract:

“Amazon Managed Service for Apache Flink enables you to process streaming data in real time, integrating with Kinesis Data Streams as source and sink, and is fully managed and serverless.”

(Source: Apache Flink on AWS documentation)

B: S3/Redshift is not real-time and adds complexity.

C, D: EC2/ECS solutions are not serverless or fully managed.

For logs that are:

Written and processed within a short period (24 hours)

Accessed quickly for compute/analytics

With unknown object count and size

Amazon S3 Standard is the most appropriate and cost-effective. Intelligent-Tiering is designed for data stored for longer periods (typically 30+ days) with changing access patterns and charges a per-object monitoring and automation fee that becomes inefficient for very short-lived objects.

S3 Glacier Deep Archive and S3 One Zone-IA are optimized for long-term archival or infrequently accessed data with retrieval time or availability constraints that are not suitable for nightly active processing.

Amazon Elastic File System (EFS) is a managed file storage service that can be mounted across multiple EC2 instances. It provides a scalable and high-performing solution to share data among instances within a VPC.

High Performance: EFS provides scalable performance for workloads that require high throughput and IOPS. It is particularly well-suited for applications that need to share data across multiple instances.

Ease of Use: EFS can be easily mounted on multiple instances across different Availability Zones, providing a shared file system accessible to all the instances within the VPC.

Security: EFS can be configured to ensure that data remains within the VPC, and it supports encryption at rest and in transit.

Why Not Other Options?:

Option A (Amazon S3 bucket with APIs): While S3 is excellent for object storage, it is not a file system and does not provide the low-latency access required for shared data between instances.

Option B (S3 bucket as a mounted volume): S3 is not designed to be mounted as a file system, and this approach would introduce unnecessary complexity and latency.

Option C (EBS volume shared across instances): EBS volumes cannot be attached to multiple instances simultaneously. It is not designed to be shared across instances like EFS.

AWS References:

Amazon EFS- Overview of Amazon EFS and its features.

Best Practices for Amazon EFS- Recommendations for using EFS with multiple instances.

Amazon API Gatewayprovides a scalable and reusable solution for interacting with DynamoDB without requiring direct access by developers. By setting up a REST API with a POST methodthat integrates with DynamoDB'sPutItemaction, developers can submit data (such as user ratings) to the DynamoDB table through API Gateway, without having to directly interact with the database. This solution is serverless and minimizes operational overhead.

Option A: Using ALB with Lambda adds complexity and is less efficient for this use case.

Option B: While using Lambda is possible, API Gateway provides a more scalable, reusable interface.

Option C: SQS with Lambda introduces unnecessary components for a simple put operation.

AWS References:

Amazon API Gateway with DynamoDB

To handle unpredictable traffic surges and improve scalability, Auto Scaling is essential. Creating an AMI and deploying it into an Auto Scaling group behind an Application Load Balancer (ALB) allows AWS to automatically scale the number of EC2 instances based on demand.

This architecture improves availability and responsiveness by distributing traffic and launching instances when needed. Option A satisfies the need for high scalability and resilience. Other options either lack Auto Scaling or are more complex without added benefit in this context.

Using SQS as a buffer between S3 and the Lambda function ensures durability and allows for retries in case of processing failures. Messages in the queue can be retried by Lambda, and failed processing can be directed to a dead-letter queue for further inspection. This guarantees reliable and scalable message-driven processing.

AWS Backup offers centralized management, scheduling, and retention of backups for supported AWS services including Amazon DynamoDB. It enables compliance retention with minimal management.

From AWS Documentation:

“AWS Backup provides centralized backup management across AWS services, including DynamoDB. You can define backup plans, schedules, and retention policies to meet business or regulatory requirements.”

(Source: AWS Backup Developer Guide – Backing up DynamoDB Tables)

Why B is correct:

Automatically manages backup scheduling and retention (7 years).

Centralized compliance monitoring via AWS Backup Audit Manager.

Fully managed and requires no custom automation.

Why others are incorrect:

A: PITR is for continuous restore within 35 days, not long-term compliance retention.

C & D: Manual or Lambda-based backups require custom management and increase operational complexity.

Amazon Aurora PostgreSQL with Babelfish allows Aurora to understand SQL Server T-SQL and the SQL Server wire protocol. This enables applications to continue using SQL Server drivers, minimizing code changes (Option B).

Migration of schema and data is performed using AWS Schema Conversion Tool (SCT) and AWS Database Migration Service (DMS) (Option C), which is the AWS-recommended migration pattern for heterogeneous database migrations.

AWS DMS (Option E) does not rewrite application SQL.

RDS Proxy (Option D) does not translate SQL Server protocols.

Option A requires rewriting application queries, which contradicts the “minimal changes” requirement.

Predictive scaling automatically analyzes historical workload patterns, forecasts future capacity needs, and launches instances ahead of time. AWS documentation states that predictive scaling is designed for workloads with recurring, cyclical patterns—such as scheduled weekly batch jobs.

It also supports "pre-launching" capacity before peak demand. This eliminates manual trend analysis and delivers the lowest operational overhead.

Scheduled scaling (Option B) works but requires manual calculation of capacity numbers and updating if patterns change. Predictive scaling removes this burden entirely.

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AWS Glue Crawler: AWS Glue is a fully managed ETL (Extract, Transform, Load) service that makes it easy to prepare and load data for analytics. A Glue crawler can automatically discover new data and schema in Amazon S3, making it easy to keep the data catalog up-to-date.

Crawling the Data:

Set up an AWS Glue crawler to scan the S3 bucket containing the clickstream data.

The crawler will automatically detect the schema and create/update the tables in the AWS Glue Data Catalog.

Amazon Athena:

Athena is an interactive query service that makes it easy to analyze data in Amazon S3 using standard SQL.

Once the data catalog is updated by the Glue crawler, use Athena to query the clickstream data directly in S3.

Operational Efficiency: This solution leverages fully managed services, reducing operational overhead. Glue crawlers automate data cataloging, and Athena provides a serverless, pay-per-query model for quick data analysis without the need to set up or manage infrastructure.

Why Option D is Correct:

IAM Roles with Instance Profiles: Allow applications to access AWS services securely without hardcoding long-term access keys.

Short-Term Credentials: IAM roles issue short-term credentials dynamically managed by AWS.

Why Other Options Are Not Ideal:

Option A and B: Embedding or retrieving long-term access keys introduces security risks and operational overhead.

Option C: Combining IAM roles with Parameter Store adds unnecessary complexity.

AWS References:

IAM Roles and Instance Profiles:AWS Documentation - IAM Roles

Aurora Replicas: Provide read scalability and high availability. They allow offloading read traffic from the primary database instance.

AWS Global Accelerator: Provides improved availability and performance by routing user requests to the optimal endpoint using AWS’s global network.

“Aurora Replicas can be used to increase read scalability and availability.”

— Aurora Replicas

“AWS Global Accelerator improves the availability and performance of your applications with global users.”

— AWS Global Accelerator

Together, these enhance both the database and network layer resilience.

The workload is bursting and must be able to buffer more orders than the printers can process. The best practice for this is a durable, scalable queue: Amazon SQS.

SQS decouples the frontend from the backend and can handle large, spiky volumes of messages.

AWS Lambda is a good fit for processing messages from SQS because it scales automatically with queue depth and requires no server management.

Deploying the frontend in Docker on Amazon ECS with Fargate provides a fully managed, auto-scaling container environment without managing EC2 instances.

Why others are not correct:

A and D: SNS is a pub/sub service, not a queue; it does not provide durable back-pressure buffering when the printers are slower than incoming requests. Lambda@Edge is for CloudFront edge processing, not back-end order processing.

B: Same SNS issue—no durable queue semantics and not ideal for workload that must be buffered and retried.

CloudFront geographic restrictions (also known as geo-blocking) allow you to allow or deny content delivery to specific countries with minimal configuration.

“You can use geo restriction, also known as geoblocking, to prevent users in specific geographic locations from accessing content that you're distributing through a CloudFront web distribution.”

— CloudFront Geo Restriction

This is the most operationally efficient approach — no code, no signed URL logic.

Incorrect Options:

A/C: Signed URLs/cookies are for individual access control, not geo-blocking.

D: OAC controls access between CloudFront and S3, not to block specific countries.

Amazon EMR provides a managed big data framework that supports Apache Spark, which is ideal for distributed and compute-intensive data transformations. Managed scaling dynamically adjusts cluster resources, ensuring high performance with minimal management.

From AWS Documentation:

“Amazon EMR provides a managed environment for big data frameworks such as Apache Spark and Hadoop. With managed scaling, EMR automatically resizes clusters to meet workload demands.”

(Source: Amazon EMR Developer Guide)

Why B is correct:

Provides distributed parallel processing for large datasets.

Reduces operational overhead with managed scaling and auto-termination.

Integrates easily with S3, Glue, and ML pipelines.

Optimized for heavy ETL and analytics workloads.

Why others are incorrect:

A: Manual scaling and limited processing capacity.

C & D: Lambda has execution time and memory limits unsuitable for 30-minute compute-intensive tasks.

AWS documentation states that workloads running 24/7 should use Reserved Instances or Savings Plans for the lowest cost. Therefore, the frontend nodes, which always run, should use Reserved Instances.

The backend nodes process asynchronous, restartable jobs, which makes them ideal for EC2 Spot Instances, the most cost-effective compute option for interruption-tolerant workloads.

Fargate (Options A and D) is significantly more expensive for large compute usage. Spot Instances cannot be used for critical frontend nodes (Option C).

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This solution allows for secure and least-privilege access with minimal operational overhead.

IAM Identity Center: AWS IAM Identity Center (formerly AWS SSO) enables you to centrally manage access to multiple AWS accounts and applications. By using IAM Identity Center, you can assign permission sets that define what users or groups can access, ensuring that only necessary permissions are granted.

Permission Sets: Permission sets in IAM Identity Center allow you to define granular access controls for specific services, such as Amazon RDS and S3. You can tailor these permissions to meet the needs of different teams, adhering to the principle of least privilege.

Group Management: By assigning users to groups and associating those groups with specific permission sets, you reduce the complexity and overhead of managing individual IAM roles and policies. This method also simplifies compliance and audit processes.

Why Not Other Options?:

Option A (IAM roles): While IAM roles can provide least-privilege access, managing multiple roles and policies across teams increases operational overhead compared to using IAM Identity Center.

Option C (Individual IAM users): Managing individual IAM users and roles can be cumbersome and does not scale well compared to group-based management in IAM Identity Center.

Option D (AWS Organizations with cross-account roles): Creating separate accounts and cross-account roles adds unnecessary complexity and overhead for this use case, where IAM Identity Center provides a more straightforward solution.

AWS References:

AWS IAM Identity Center- Overview and best practices for using IAM Identity Center.

Managing Access Permissions Using IAM Identity Center- Guide on creating and managing permission sets for secure access.

A. VPC peering:Creates a fully meshed architecture, which is complex to manage for multiple VPCs.

B. Transit gateway:Simplifies network management by connecting multiple VPCs and on-premises networks via a central hub.

C. PrivateLink:Restricts communication to the application endpoint but may not allow full VPC connectivity.

D. ALB with internet exposure:Not secure or specific to private network communication.

To securely access AWS services like S3 and Secrets Manager from a private VPC without using public IPs, interface VPC endpoints are required. These endpoints are accessible via private IP addresses. For the application to reach these endpoints, appropriate routes must be configured in the route table.

AWSService Catalogis designed to allow organizations to manage a catalog of approved products (including AMIs) that users can deploy. By creating a portfolio that contains only EC2 instances launched with preapproved AMIs, the company can enforce compliance with the approved operating system and software for all EC2 instances. Service Catalog also streamlines the process of launching EC2 instances, reducing the lead time while ensuring that developers use only the approved configurations.

Option B (EC2 Image Builder): While EC2 Image Builder helps in creating and managing AMIs, it doesn't provide the enforcement mechanism that Service Catalog does.

Option C (EventBridge rule and Systems Manager script): This solution is reactive and involves more operational complexity compared to Service Catalog.

Option D (AWS Config rule): This option is reactive (it terminates non-compliant instances after launch) and introduces additional operational overhead.

AWS References:

AWS Service Catalog

AWS Config has a built-in managed rule (access-keys-rotated) that evaluates IAM access key age. Config rules detect non-compliant resources automatically, without building custom logic.

After Config identifies old keys, EventBridge can trigger an AWS Lambda function to disable and delete the keys. Lambda provides a fully managed compute layer requiring no servers or batch environments.

Using AWS Batch (Options A, B, and D) adds unnecessary operational overhead for a simple automation task.

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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.

Amazon Aurora Serverless is a fully managed, MySQL-compatible database that automatically scales based on demand and provides high availability. Combining this with EC2 Auto Scaling and an Application Load Balancer achieves both application and database high availability and scalability.

Reference Extract:

"Aurora Serverless automatically starts up, shuts down, and scales capacity based on your application's needs, providing a cost-effective, highly available database solution."

Source: AWS Certified Solutions Architect – Official Study Guide, Aurora Serverless and Scaling section.

AWS Step Functions is the recommended service for orchestrating multi-step, long-running workflows with state tracking, retries, and external API calls. It reduces operational overhead by eliminating the need for custom orchestration logic.

API Gateway receiving work items and sending them to SQS (Option E) provides buffering, elasticity, and decoupling, ensuring immediate ingestion regardless of backend load.

Option A forces Lambda to handle long execution paths, which is not optimal for 30-minute tasks and multi-state workflows. Option C triggers Lambda directly without buffering. Option D uses fixed EC2 instances, which does not scale dynamically.

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When designing a microservice architecture where each microservice interacts with different AWS services, it's essential to follow the principle of least privilege. This means granting each microservice only the permissions it needs to perform its tasks, reducing the risk of unauthorized access or accidental actions.

The recommended approach is to create individualIAM roleswith policies that grant each microservice the specific permissions it requires. Then, these roles should be associated with the EC2 instances that run the corresponding microservice. By doing so, each EC2 instance will assume its specific IAM role, and permissions will be automatically managed by AWS.

IAM roles provide temporary credentials via the instance metadata service, eliminating the need to hard-code credentials in your application code, which enhances security.

AWS References:

IAM Roles for Amazon EC2explains how EC2 instances can use IAM roles to securely access AWS services without managing long-term credentials.

Best Practices for IAMincludes recommendations for implementing the least privilege principle and using IAM roles effectively.

Why the other options are incorrect:

A. Assign an IAM user to each microservice: This requires managing long-term credentials (access keys), which should be avoided. Storing keys in application code is insecure and creates a maintenance burden.

B. Create a single IAM role: This violates the principle of least privilege, as a single role with broad permissions across all services is less secure.

C. Use AWS Organizations: This approach adds unnecessary complexity. Managing permissions at the account level for each microservice is excessive for this use case and doesn't adhere to the principle of least privilege.

Amazon S3 Multi-Region Access Points allow applications to access S3 buckets in multiple Regions through a single global endpoint. This provides active-active read access with automatic routing to the closest bucket for low latency. With cross-Region replication, writes in the primary Region are automatically copied to the secondary Region, providing fault tolerance. Option A (CloudFront) provides caching and distribution, but does not address write replication or active-active bucket access. Option B (Transfer Acceleration) optimizes uploads across distances but does not enable cross-Region fault tolerance. Option C (AWS Backup) is designed for backup/restore, not real-time multi-Region reads and writes. Therefore, D is the correct solution for active-active read access and disaster recovery.

The most cost-effective and scalable solution for generating thumbnails when photos are uploaded to an S3 bucket is to useS3 event notificationsto trigger anAWS Lambda function. This approach avoids the need for a long-running EC2 instance or EMR cluster, making it highly cost-effective because Lambda only charges for the time it takes to process each event.

S3 Event Notifications: Automatically triggers the Lambda function when a new photo is uploaded to the S3 bucket.

AWS Lambda: A serverless compute service that scales automatically and only charges for execution time, which makes it the most economical choice when dealing with periodic events like photo uploads.

The Lambda function can generate the thumbnail and upload it to a second S3 bucket, fulfilling the requirement efficiently.

Option AandOption B(EMR or EC2 with scheduled scripts)**: These are less cost-effective as they involve continuously running infrastructure, which incurs unnecessary costs.

Option D (S3 Storage Lens): S3 Storage Lens is a tool for storage analytics and is not designed for event-based photo processing.

AWS References:

Amazon S3 Event Notifications

AWS Lambda Pricing

AWS Direct Connect provides a dedicated network connection from on-premises to AWS, offering greater bandwidth and more consistent performance than internet-based connections or VPN. AWS PrivateLink enables secure, private connectivity to supported AWS services such as Kinesis Data Firehose over Direct Connect, bypassing the public internet and providing the highest throughput and lowest latency possible. This is the recommended solution for consistently transferring large volumes of data with maximum reliability and performance.

Reference Extract from AWS Documentation / Study Guide:

"AWS Direct Connect and AWS PrivateLink provide private, high-throughput connectivity between on-premises and AWS services, bypassing the public internet and ensuring maximum performance for large data transfers."

Source: AWS Certified Solutions Architect – Official Study Guide, Hybrid Networking section.

Comprehensive and Detailed Step-by-Step Explanation:

To accurately charge customers based on their monthly data download usage, the following solution is recommended:

Structured Logging Configuration:

Action:Ensure that the AWS Transfer for SFTP server is configured to log user activity, including details about file downloads, to Amazon S3 in a structured format.

Implementation:Utilize AWS Transfer Family's structured logging feature to capture detailed information about user sessions, including actions performed and data transferred.

docs.aws.amazon.com

Justification:Structured logs provide comprehensive data necessary for analyzing customer-specific download activities.

Data Analysis with Amazon Athena:

Action:Use Amazon Athena to run SQL queries on the structured log data stored in the S3 bucket to calculate the amount of data each customer has downloaded.

Implementation:

a.Define a Schema:Create a table in Athena that maps to the structure of your log files. This involves specifying the format of the logs and the location in S3.

b.Query Data:Write SQL queries to sum the total bytes downloaded by each customer over the billing period. This can be achieved by filtering logs based on user identifiers and summing the data transfer amounts.

Justification:Athena allows for efficient querying

Amazon Transcribe supports automatic speech recognition (ASR) with speaker diarization (i.e., multiple speaker identification). The transcripts can be stored in Amazon S3 and queried using Amazon Athena, which provides a serverless, pay-as-you-go interactive querying model.

To grant cross-account access to an Amazon S3 bucket, you can use a bucket policy that specifies the AWS account ID of the account you want to grant access to. This method allows Account B to access the S3 bucket in Account A without the need for additional services or configurations.

AWS Step Functions provides a low-code, fully managed workflow service with a visual interface to orchestrate AWS Glue jobs in sequence. Step Functions integrates natively with AWS Glue and can be triggered by Amazon EventBridge based on events or schedules.

AWS Documentation Extract:

“AWS Step Functions makes it easy to coordinate multiple AWS services into serverless workflows so you can build and update apps quickly. Step Functions provides visual workflows and integrates with AWS Glue for ETL orchestration.”

(Source: AWS Step Functions documentation)

A: Manual scripting and dashboards do not provide a low-code or integrated visual workflow.

C: QuickSight is for BI, not workflow visualization.

D: ECS adds unnecessary complexity.

A. Amazon EFS:Provides a scalable, shared file storage solution with minimal operational overhead. It's ideal for Linux-based workloads.

B. Amazon FSx for NetApp ONTAP:More suited for workloads requiring NetApp-specific features.

C. Amazon EBS:Requires manual management of file shares, which increases operational overhead.

D. Amazon FSx for Windows File Server:Best suited for Windows SMB workloads with low operational overhead.

E. Amazon FSx for OpenZFS:Better for Linux and Unix-based workloads.

This solution is designed to provide high availability and low-latency access to block storage across multiple Availability Zones with minimal implementation effort.

Windows Server Cluster Across AZs: Configuring a Windows Server Failover Cluster (WSFC) that spans two Availability Zones ensures that the application can failover from one instance to another in case of a failure, meeting the high availability requirement.

Amazon FSx for Windows File Server: FSx for Windows File Server provides fully managed Windows file storage that is accessible via the SMB protocol, which is suitable for Windows-based applications. It offers high availability and can be used as shared storage between the cluster nodes, ensuring that both nodes have access to the same data with low latency.

Why Not Other Options?:

Option B (EBS with application-level replication): This requires complex configuration and management, as EBS volumes cannot be directly shared across AZs. Application-level replication is more complex and prone to errors.

Option C (FSx for NetApp ONTAP with iSCSI): While this is a viable option, it introduces additional complexity with iSCSI and requires more specialized knowledge for setup and management.

Option D (EBS with EBS-level replication): EBS-level replication is not natively supported across AZs, and setting up a custom replication solution would increase the implementation effort.

AWS References:

Amazon FSx for Windows File Server- Overview and benefits of using FSx for Windows File Server.

Windows Server Failover Clustering on AWS- Guide on setting up a Windows Server cluster on AWS.

For cost-effectiveness and high availability in Amazon EMR workloads, the best approach is to configure atransient cluster(which runs for the duration of the job and then terminates) withOn-Demand Instancesfor the primary and core nodes, andSpot Instancesfor the task nodes. Here's why:

Primary and core nodes on On-Demand Instances: These nodes are critical because they manage the cluster and store data on HDFS. Running them on On-Demand Instances ensures stability and that no data is lost, as Spot Instances can be interrupted.

Task nodes on Spot Instances: Task nodes handle additional processing and can be used with Spot Instances to reduce costs. Spot Instances are much cheaper but can be interrupted, which is fine for non-critical tasks as the framework can handle retries.

Atransient clusteris more cost-effective than a long-running cluster for workloads that only run for 6 hours a day. Transient clusters automatically terminate after the workload completes, saving costs by not keeping the cluster running when it's not needed.

Option A: A long-running cluster may result in unnecessary costs when the cluster isn't being used.

Option C: Running core nodes on Spot Instances risks data loss if the Spot Instances are interrupted, violating the requirement for zero data loss.

Option D: Running both core and task nodes on Spot Instances is highly risky for data-critical workloads.

AWS References:

Amazon EMR Cluster Management

Using Spot Instances in EMR

Key Requirements:

High availability and automatic recovery.

Separate transactional and analytical queries with minimal performance impact.

Allow up to a 4-hour lag for analytical queries.

Analysis of Options:

Option A:

Multi-AZ deployments provide high availability but do not include read replicas for separating transactional and analytical queries.

Analytical queries on the secondary DB instance would impact the transactional workload.

Incorrect Approach:Does not meet the requirement of query separation.

Option B:

Multi-AZ DB clusters provide high availability and include a reader endpoint. However, these are better suited for Aurora and not RDS for MySQL.

Incorrect Approach:Not applicable to standard RDS for MySQL.

Option C:

Multiple read replicas allow separation of transactional and analytical workloads.

Queries can be pointed to a replica in a different AZ, ensuring no impact on transactional queries.

Correct Approach:Meets all requirements with high availability and query separation.

Option D:

Creating nightly snapshots and read-only databases adds significant operational overhead and does not support the 4-hour lag requirement.

Incorrect Approach:Not practical for dynamic query separation.

AWS Solution Architect References:

Amazon RDS Read Replicas

Multi-AZ Deployments

Aurora Global Database is designed for low-latency cross-Region reads and disaster recovery for relational data.

Amazon S3 Cross-Region Replication (CRR) automatically replicates unstructured data to another Region, ensuring high availability and resilience.

“Aurora Global Database replicates your data with typical latency of less than 1 second to secondary AWS Regions.”

“Amazon S3 Cross-Region Replication automatically replicates every object uploaded to your bucket to a destination bucket in another AWS Region.”

— Aurora Global Database

— S3 Cross-Region Replication

This combination meets the multi-Region, high availability, fault-tolerant requirement for both relational and unstructured data.

AWS Secrets Manager is the managed service for securely storing, rotating, and retrieving database credentials. When you store Aurora credentials in Secrets Manager and enable automatic rotation, Secrets Manager updates the credentials in both the database and the stored secret.

Each Lambda function version or alias can call Secrets Manager at runtime to retrieve the current secret value, so even older deployed Lambda versions that use an alias will always obtain the most recent credentials without redeployment.

Why others are not suitable:

B: Embeds credentials in code, requiring redeployment on every rotation and violating security best practices.

C: Environment variables are version-specific; old aliases would continue using outdated values unless you redeploy or change them.

D: Parameter Store can store and rotate secrets but is less integrated for database credential rotation than Secrets Manager; Secrets Manager is the purpose-built minimal-overhead choice here.

To grant the ECS application the least privilege, you create an IAM policy that explicitly lists the ARNs of the specific S3 buckets the task should access. You then attach this policy to the task role (not the instance role), ensuring only that task has the necessary permissions. This approach avoids granting permissions to other EC2 instances or services and restricts access strictly to the required buckets.

AWS Documentation Extract:

"Attach an IAM policy granting access to specific resources to the ECS task role, not to the instance role, to ensure that only the container has access according to the principle of least privilege."

"Use explicit ARNs to control access only to specified S3 buckets."

(Source: Amazon ECS documentation, IAM Roles for Tasks)

A: Tag-based access control for S3 buckets is possible but less direct and commonly used for identity-based access.

C: Attaching the policy to the instance role could grant unintended permissions to all containers or services running on the instance.

D: Wildcard ARNs grant broader access than necessary.

The correct and secure approach is to use Amazon CloudFront with Origin Access Control (OAC) to protect the S3 origin and attach AWS WAF to the CloudFront distribution to inspect and filter traffic at the edge before reaching the origin.

From AWS Documentation:

“AWS WAF is integrated with Amazon CloudFront, allowing inspection of HTTP(S) requests at the edge location before forwarding to your origin. To restrict direct access to the S3 bucket, use Origin Access Control (OAC).”

(Source: Amazon CloudFront Developer Guide – Serving private content)

Why Option D is correct:

CloudFront is the only service that integrates with AWS WAF for full HTTP layer inspection.

Origin Access Control (OAC) ensures that only CloudFront can access the S3 origin—replacing older Origin Access Identity (OAI) features.

The S3 bucket policy is configured to trust requests only from CloudFront using OAC signed requests.

Why the other options are incorrect:

Option A: WAF ARN is not a principal in S3 bucket policy. IAM does not support bucket policies based on WAF ARNs.

Option B: Incorrect – CloudFront doesn't "forward requests to WAF"; rather, WAF is associated with CloudFront and inspects requests at the edge.

Option C: S3 does not use security groups; they are for EC2/network interfaces. This shows a misunderstanding of how S3 works.

This solution offers the least operational overhead while meeting the security and global availability requirements:

Amazon CloudFront and S3: Hosting the static frontend on S3 and serving it via CloudFront provides low-latency global distribution, high availability, and security. S3 is a cost-effective and serverless option for hosting static assets, and CloudFront ensures that the application is cached closer to the users, reducing latency globally.

AWS Lambda and API Gateway: Refactoring the microservices to use Lambda functions with API Gateway allows for a fully serverless, scalable, and highly available backend. This reduces the need for managing EC2 instances, as Lambda automatically scales to meet demand and only charges for the actual usage.

RDS for MySQL: Migrating the MySQL database from an EC2 instance to Amazon RDS significantly reduces operational overhead. RDS manages backups, patching, and scaling, and it offers high availability options (e.g., Multi-AZ).

Option AandDinvolve using EC2 Reserved Instances for the database, which requires more operational maintenance than using RDS.

Option Csuggests using a Network Load Balancer with Lambda, which adds unnecessary complexity for this use case.

AWS References:

Amazon S3 and CloudFront Integration

AWS Lambda with API Gateway

Amazon RDS for MySQL

AWS X-Ray is the AWS service designed for distributed tracing, giving end-to-end visibility into how requests flow through microservices, APIs, and serverless components. It provides service maps, latency breakdowns, and performance insight per service, which is exactly what is required.

To use X-Ray effectively, each application stack must be instrumented. For infrastructure deployed through AWS CloudFormation, best practice is to enable and configure X-Ray in the CloudFormation templates (for Lambda, API Gateway, ECS, etc.). That way, all teams and stacks have consistent tracing enabled as part of their IaC.

Control Tower (Option B) cannot “turn on” X-Ray tracing inside applications; it only helps with account setup and guardrails.

CloudTrail (Option A) is for audit logging of API calls, not performance tracing.

CloudWatch (Option C) provides metrics and logs, but not request-level distributed tracing across multiple services.

Amazon EFS Lifecycle Management enables automatic cost optimization by transitioning files that haven’t been accessed for a defined period (e.g., 7 days) from EFS Standard to EFS Infrequent Access (IA).

“Amazon EFS Lifecycle Management automatically moves files that haven’t been accessed for a set period to the EFS Infrequent Access storage class, reducing storage costs for infrequently accessed files.”

— Amazon EFS Documentation

Key Points:

EFS IA is ideal for files larger than 128 KB and accessed less frequently.

It’s seamless — no code or tools needed.

Meets requirement for cost optimization and high availability.

Incorrect Options:

A: File Gateway adds unnecessary complexity and does not use EFS.

B: Storing files locally breaks shared access and resiliency.

D: Glacier Deep Archive is cold storage — not "readily available."

For Amazon RDS for PostgreSQL, AWS provides IAM database authentication. With this feature, applications do not use stored long-term usernames and passwords. Instead, they use temporary authentication tokens that are generated by AWS and validated by the RDS database.

The AWS best practice pattern is:

Attach an IAM role to the EC2 instances (instance profile).

Grant that role the necessary permissions (for example, rds-db:connect) to the specific RDS database user.

The application running on the EC2 instance uses the role’s temporary credentials to call the RDS token-generation API and obtain a short-lived authentication token.

The application then uses this token as the password when connecting to RDS for PostgreSQL.

This removes the need to store long-term credentials in the application or on the instance and uses IAM roles with temporary credentials, aligning with the security requirement.

Option A still relies on stored credentials (even if in Secrets Manager), which are long-lived and rotated but not token-based per-connection IAM authentication.

Option B uses static passwords and IP-based access, which does not meet the “no long-term credentials” requirement.

Option C stores long-term IAM user keys on the instances, which is explicitly against best practices and does not directly integrate with RDS authentication.

AWS Config allows for creation of custom rules to monitor EBS configurations. Combined with CloudWatch metrics and Amazon SNS, custom rules can track over-provisioned IOPS and send alerts when thresholds are breached, allowing proactive cost and performance management.

Amazon DynamoDB provides single-digit millisecond performance at any scale and is fully managed to handle millions of catalog records. It is ideal for structured catalog data such as product metadata and scales seamlessly during high-traffic events like sales. Amazon S3 is optimized for storing unstructured large objects such as videos and manuals, with virtually unlimited scalability and high durability. Option A (RDS) would not handle massive scale or traffic spikes as efficiently. Option C overloads DynamoDB by forcing it to store large binary data, which is not its purpose. Option D (DocumentDB) is suitable for JSON-like documents but not optimal for storing large media files and would add operational complexity. Therefore, option B represents the best separation of structured and unstructured data storage.

Amazon DynamoDB supports TTL (Time To Live) for automated, scheduled deletion of expired items. It also offers point-in-time recovery (PITR) to restore the table to any second within the retention window (typically up to 35 days), providing full data durability and protection. DynamoDB can efficiently handle frequent updates and offers predictable performance. MemoryDB is an in-memory store, not designed for durable recovery. S3 with lifecycle policies does not handle updates as efficiently for small, frequent writes and is not as optimal for session data.

Reference Extract:

"DynamoDB supports TTL for automated expiration and deletion of items and PITR for continuous backups and restoration of data."

Source: AWS Certified Solutions Architect – Official Study Guide, DynamoDB section.

Amazon Macieis purpose-built for detecting PII in S3.

Option Auses EventBridge to filter SensitiveData findings and notify via SNS, meeting the requirements.

Options B and Dinvolve GuardDuty, which is not designed for PII detection.

Option Cuses SQS, which is less suitable for immediate notifications.

AWS Outposts extends AWS infrastructure and services to on-premises locations. Running Amazon EMR on Outposts allows for processing data that resides locally while benefiting from the managed services of EMR. This enables compliance with data residency requirements and provides scalability and manageability for analytics.

EC2 Image Builder is the AWS-managed service specifically designed to automate the creation, patching, hardening, and testing of AMIs.

For this scenario, best practice is to:

Use EC2 Image Builder pipelines to generate new golden AMIs whenever features are deployed or on a schedule.

Include build components such as update-linux to automatically apply OS security patches and updates during image creation.

Deploy the new AMIs through existing Auto Scaling groups, ensuring that every newly launched instance is already patched and compliant.

This approach:

Prevents OS vulnerabilities from being introduced at deployment time.

Scales across dozens of applications because AMI pipelines are reusable and automated.

Minimizes manual effort and reduces drift between instances.

Amazon Inspector (Option A) identifies vulnerabilities but does not itself patch AMIs.

AWS Backup (Option B) is for data protection, not vulnerability management.

Patch Manager (Option C) patches running instances, but the requirement is to ensure vulnerabilities are not introduced with new AMIs; golden image pipelines with EC2 Image Builder are the recommended solution.

Explanation (AWS Docs):

ElastiCache provides an in-memory cache layer for frequently accessed queries, reducing latency and offloading read pressure from the database.

“You can improve database performance by caching frequently accessed data using Amazon ElastiCache.”

— ElastiCache Overview

To securely migrate an on-premises Oracle database to Amazon Aurora, the following steps are recommended:

Use AWS Schema Conversion Tool (AWS SCT) and AWS Database Migration Service (AWS DMS): AWS SCT helps convert the source database schema to a format compatible with the target database (Aurora). AWS DMS facilitates the actual data migration, ensuring minimal downtime and data integrity.

Use AWS Site-to-Site VPN: Establishing a Site-to-Site VPN connection provides a secure and encrypted tunnel between the on-premises environment and AWS. This ensures that data transferred during the migration is protected against interception and unauthorized access.

DynamoDB Streams: Captures real-time changes in DynamoDB tables and allows integration with Lambda for processing the changes.

Minimal Operational Overhead: Using a Lambda function directly to write data to S3 ensures simplicity and reduces the complexity of the pipeline.

Amazon DynamoDB Streams Documentation

Step A:AWS WAF with managed rules protects the API against application-layer attacks, such as SQL injection and cross-site scripting (XSS).

Step C:Amazon Cognito provides secure authentication and supports federation with social IdPs using OIDC or SAML. It integrates seamlessly with API Gateway.

Option B:AWS Shield Advanced provides DDoS protection, which is not explicitly required in this scenario.

Option D:API keys provide identification, not authentication, and are insufficient for this use case.

Option E:IP filters in WAF are overly restrictive for federated authentication scenarios.

AWS Documentation References:

Amazon Cognito Federation

AWS WAF Managed Rules

Amazon S3 supports one Lifecycle configuration per bucket that can contain multiple rules. Lifecycle rules can include filters, including object size filters: ObjectSizeGreaterThan and ObjectSizeLessThan. You can combine rules so that one targets large objects and another provides a default expiration. Here, configure Rule 1 with a size filter ObjectSizeGreaterThan = 1 TB and Expiration = 2 days (48 hours) to purge very large videos early. Configure Rule 2 with Expiration = 7 days without a size filter to serve as a catch-all maximum retention for all objects. Options B and D are invalid because S3 does not allow multiple Lifecycle configurations per bucket. Option C cannot distinguish large files; it would delete all files at the same schedule without honoring the 48-hour policy for >1 TB objects. This single configuration with two rules meets both retention targets with minimal overhead and full S3-native capability.

Amazon RDSMulti-AZ DB cluster deploymentensures high availability by automatically replicating data across multiple Availability Zones (AZs), and it supports failover in case of a failure in one AZ. This setup also provides increased capacity for read workloads by allowing read scaling with reader instances in different AZs. This solution offers the most operational efficiency with minimal manual intervention.

Option A (DynamoDB): DynamoDB is not suitable for a relational database workload, which requires a PostgreSQL engine.

Option B (RDS with Multi-AZ): While this provides high availability, it doesn't offer read scaling capabilities.

Option D (Cross-Region Read Replicas): This adds complexity and is not necessary if the requirement is high availability within a single region.

AWS References:

Amazon RDS Multi-AZ DB Cluster

AWS documentation states that the most secure method for granting private S3 access from VPCs is to use gateway VPC endpoints for Amazon S3. Endpoint policies enforce least privilege by allowing only specific IAM roles access to specific S3 buckets. Because users can obtain temporary credentials through IAM roles, no permanent access keys must be distributed.

S3 bucket policies based on CIDR ranges (Option B) are less secure because CIDR-based access is broader and can grant unintended access. Access points (Option C) still rely on public S3 endpoints unless combined with VPC-only access, which is not stated here. Option D exposes S3 to public internet egress and depends on public IPs, violating least-privilege principles.

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Amazon EFS is a regional, elastic file system that “scales to petabytes” and can be accessed from “thousands of compute instances” concurrently. You can mount EFS across VPCs and across AWS accounts by providing network connectivity (e.g., VPC peering) to the EFS mount targets and allowing NFS (TCP 2049) in the mount target security group, optionally using EFS access points and a file system policy for cross-account access control. VPC peering has no hourly charge and minimal operational overhead, and EFS automatically scales as files are added—meeting the scalability and cost goals.

Option A duplicates data, incurs DataSync and extra storage costs, and adds sync lag.

Option C adds an extra Lambda hop and complexity without exposing a shared filesystem to the primary function.

Option D is impractical: Lambda layers are immutable artifacts with tight size limits (up to 50 MB compressed/250 MB uncompressed) and are not suited for dynamic, growing file sets.

AWS Lake Formation natively supports fine-grained access control, including:

Row-level security

Cell/column-level security

These are implemented through data filters and Lake Formation permissions on governed tables and views. This allows you to centrally define which users or groups can access which rows and which columns, including sensitive data fields, with minimal custom code or maintenance.

Why others are incorrect:

A: IAM alone does not provide row-level or cell-level data security inside Lake Formation tables.

C and D: Using Lambda to scrub or periodically remove sensitive data is complex, error-prone, and high overhead compared to built-in Lake Formation data filters.

AWS Lambda supports functions up to 10 GB of memory and 15 minutes execution time. Each invocation here requires only 1 GB of memory and finishes in 30 seconds, making it an ideal fit for Lambda. Lambda is cost-effective for event-driven, short-duration workloads and requires no infrastructure management. AWS Glue and EMR are better suited for large-scale ETL or distributed processing, which is unnecessary and more costly for this workload.

AWS Documentation Extract:

“AWS Lambda is a serverless compute service that lets you run code without provisioning or managing servers. You pay only for the compute time you consume. Lambda supports up to 10 GB memory and 15 minutes per invocation.”

(Source: AWS Lambda documentation)

B, D: AWS Glue is intended for ETL on larger datasets or batch jobs, usually with higher operational overhead and cost.

C: EMR is for large-scale distributed processing and is not cost-effective for single, fast, memory-bound jobs.

Field-level encryption in Amazon CloudFront provides end-to-end encryption for specific data fields (e.g., credit card numbers, social security numbers). It ensures that sensitive fields are encrypted at the edge before being forwarded to the origin, and only the authorized application with the private key can decrypt them.

This adds a layer of protection beyond HTTPS, which encrypts the whole payload but not individual fields. Signed URLs and cookies are for access control, not encryption. Setting HTTPS Only is a good practice but does not satisfy the field-specific encryption requirement.

Enabling Multi-AZ deployment for an Amazon RDS DB instance is the simplest and most effective way to improve database availability and eliminate a single point of failure. Multi-AZ deployments provide automatic failover to a standby instance in case of a failure of the primary instance. This approach is managed by AWS and only requires a modification to the existing instance, with minimal manual intervention or downtime, thus providing the least implementation effort.

Reference Extract from AWS Documentation / Study Guide:

"With Multi-AZ deployments, Amazon RDS automatically creates a primary DB Instance and synchronously replicates the data to a standby instance in a different Availability Zone (AZ). In case of a failure of the primary DB Instance, Amazon RDS automatically fails over to the standby so that database operations can resume quickly."

Source: AWS Certified Solutions Architect – Official Study Guide, RDS High Availability section.

Option Acombines ECS with Fargate for scalability, RDS for relational data, and SQS for decoupling with message ordering (FIFO queues).

Option Buses SNS, which does not maintain message order.

Option Cis suitable for serverless workflows but not relational data.

Option Drelies on Elastic Beanstalk, which offers less flexibility for scaling.

This solution provides encryption at rest and in transit with the least operational overhead while adhering to the company’s security policies.

Encryption at Rest: Amazon RDS for MySQL can be configured to encrypt data at rest by using AWS Key Management Service (KMS) managed keys. This encryption is applied automatically to all data stored on disk, including backups, read replicas, and snapshots. This solution requires minimal operational overhead because AWS manages the encryption and key management process.

Encryption in Transit: AWS Certificate Manager (ACM) allows you to provision, manage, and deploy SSL/TLS certificates seamlessly. These certificates can be used to encrypt data in transit by configuring the MySQL instance to use SSL/TLS for connections. This setup ensures thatdata is encrypted between the application and the database, protecting it from interception during transmission.

Why Not Other Options?:

Option B (IPsec tunnels): While IPsec tunnels encrypt data in transit, they are more complex to manage and require additional configuration and maintenance, leading to higher operational overhead.

Option C (Third-party application-level encryption): Implementing application-level encryption adds complexity, requires code changes, and increases operational overhead.

Option D (VPN for encryption): A VPN solution for encrypting data in transit is unnecessary and adds additional complexity without providing any benefit over SSL/TLS, which is simpler to implement and manage.

AWS References:

Amazon RDS Encryption- Information on how to configure and use encryption for Amazon RDS.

AWS Certificate Manager (ACM)- Details on using ACM to manage SSL/TLS certificates for securing data in transit.

Amazon Aurora MySQL supports the SELECT INTO OUTFILE S3 SQL syntax to export query results directly to Amazon S3. This is an efficient and low-overhead method for archiving data.

Once data is in S3, Lifecycle rules can be configured to automatically transition older data to lower-cost storage classes (such as S3 Glacier) or delete it after a defined period, providing a cost-optimized and automated archive solution.

The Glue-based options involve more services and operational overhead. SCT is intended for database migrations, not for periodic data archival.

AWS best practice for a highly available, resilient web application is:

Run EC2 instances in an Auto Scaling group across multiple Availability Zones.

Put an Application Load Balancer (ALB) in front of the Auto Scaling group.

Use CloudWatch alarms and scaling policies for horizontal scaling based on demand.

Option D implements exactly this: a minimum of three instances spread across AZs (resilience to AZ failure), behind an ALB, with automatic horizontal scaling. This provides both elasticity and high availability with good cost efficiency (instances scale out/in based on traffic).

Option A uses only three fixed instances and relies on vertical scaling, which does not scale as well and is less resilient.

Option B overprovisions to nine instances from the start, which is unnecessarily expensive.

Option C keeps all instances in a single AZ, which does not meet resilience requirements.

Amazon RDS does not support enabling encryption at rest on an existing unencrypted DB instance. To encrypt an existing RDS instance’s data at rest, the recommended method is to:

Take a snapshot of the unencrypted DB instance.

Create an encrypted copy of the snapshot using AWS KMS. This encrypted snapshot contains the existing data encrypted at rest.

Restore a new DB instance from the encrypted snapshot. This new instance will have encryption at rest enabled.

Additionally, to manage encryption keys securely, companies can use customer managed keys (CMKs) in AWS Key Management Service (KMS). CMKs provide greater control over key management policies, rotation, and usage permissions compared to default AWS managed keys. Using a CMK allows customization of access control and auditability.

Option A is incorrect because you cannot enable encryption directly on a snapshot; you must create an encrypted copy. Option C is invalid because encryption cannot be enabled by modifying an existing instance’s configuration. Option D refers to the default AWS managed key, which is less flexible than customer managed keys.

EMR runtime roles allow fine-grained permissions per job, letting each team access only the services they are authorized to use. This isolates IAM permissions per workload and avoids exposing instance-level credentials through IMDSv2. Runtime roles improve security posture in multi-tenant EMR environments.

SQS Standard queues provide at-least-once delivery; they can, by design, deliver duplicate messages, and you cannot turn that off.

To guarantee no duplicates to consumers, AWS provides SQS FIFO queues with exactly-once processing semantics in conjunction with deduplication.

The minimal change to achieve this behavior is to:

Recreate the queue as a FIFO queue and

Enable content-based deduplication, so SQS automatically deduplicates messages with identical bodies within the deduplication window.

Why others are not correct:

A: Long polling reduces empty responses and costs but does not eliminate duplicates.

C: Content-based deduplication is available only for FIFO queues, not for standard queues—so you cannot “modify” a standard queue this way.

D: Moving to Amazon MQ is a much bigger architectural change and adds more operational overhead; it’s not the “fewest changes” approach.

This solution usesCloudFrontto serve the website securely over HTTPS usingAWS Certificate Manager (ACM)for SSL certificates.Origin Access Control (OAC)ensures that only CloudFront can access the S3 bucket directly.AWS WAFwith an IP set rule restricts access to the website, allowing only the on-premises IP address.Route 53is used to create an alias record pointing to the CloudFront distribution. This setup ensures secure, private access to the website with low administrative overhead.

Option A and B: S3 bucket policies and access points do not provide HTTPS support, nor do they offer the same level of security as CloudFront with WAF.

Option D: Signed URLs are more suitable for temporary, expiring access rather than a permanent solution for on-premises employees.

AWS References:

Amazon CloudFront with Origin Access Control

For maximum resiliency and fault tolerance in a mission-critical scenario, AWS recommends redundant Direct Connect connections from multiple data centers to multiple AWS Direct Connect locations.

This protects against:

Data center failure

Device failure

Location outages

“For workloads that require high availability, we recommend that you use multiple Direct Connect connections at multiple Direct Connect locations.”

— AWS Direct Connect Resiliency Recommendations

Option C follows AWS maximum resiliency model.

Elastic Fabric Adapter (EFA) is a network interface for Amazon EC2 instances that enables high throughput, low-latency networking, and OS-bypass capabilities. EFAs are designed for applications that require fast inter-node communications, such as HPC, ML, and real-time analytics. EFA provides significantly lower latency than traditional networking, which is ideal for real-time streaming and processing workloads.

Reference Extract from AWS Documentation / Study Guide:

"Elastic Fabric Adapter (EFA) provides low-latency, high-throughput network communications required by high-performance computing applications, enabling fast, scalable, and tightly-coupled workloads on AWS."

Source: AWS Certified Solutions Architect – Official Study Guide, EC2 Networking section.

AWS Secrets Manager is the recommended service for storing database credentials and performing automated rotation. Any Lambda function version or alias can fetch the latest secret value at runtime, ensuring no outdated credentials exist in deployed versions.

Environment variables (Option C) are static per version. Embedding credentials in code (Option B) is insecure and requires redeployment. Parameter Store (Option D) supports rotation but requires more configuration and is not as seamless as Secrets Manager for database credential rotation.

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AWS Transit Gateway simplifies network connectivity by acting as a hub that can connect VPCs and on-premises networks through VPN or Direct Connect. It provides scalability and reduces administrative overhead by eliminating the need to manage complex peering relationships as the number of accounts and VPCs grows.

EKS lets teams “run Kubernetes on AWS without needing to install and operate your own Kubernetes control plane,” and with AWS Fargate, you “run Kubernetes pods without managing servers,” reducing operational overhead for worker nodes. For the data layer, Amazon DocumentDB (with MongoDB compatibility) “supports the MongoDB API and drivers,” allowing existing MongoDB applications to work without application changes, while the service “automatically scales storage,” provides “high availability across multiple Availability Zones,” automatic backups, and patching. Because the company cannot change code or deployment methods, keeping Kubernetes (EKS) and the MongoDB API (DocumentDB compatibility) is essential. Options A and C either change the orchestrator (to ECS) or the database API (to DynamoDB), which would require code/deployment changes. Option A also leaves you managing EC2 nodes and a self-managed MongoDB on EC2, increasing ops burden. Therefore, EKS on Fargate + Amazon DocumentDB minimizes operations and preserves compatibility.

A. Kinesis Data Streams:Supports high throughput, strict ordering, multiple consumers, and data retention for 365 days.

B. SNS + SQS FIFO:Can enforce ordering but lacks native support for 500 KB messages and retention requirements.

C. EventBridge:Lacks strict ordering and message size compatibility.

D. SNS + Firehose:Not designed for strict ordering or large message sizes.

Provisioned Concurrency:

AWS Lambda’s provisioned concurrency ensures that a predefined number of execution environments are pre-warmed and ready to handle requests, reducing latency during traffic spikes.

This solution optimizes costs during low-traffic periods when combined with AWS Application Auto Scaling to dynamically adjust the provisioned concurrency based ondemand.

Incorrect Options Analysis:

Option B: Switching to EC2 would increase complexity and cost for a serverless application.

Option C: A fixed concurrency level may result in over-provisioning during low-traffic periods, leading to higher costs.

Option D: Periodically warming functions does not effectively handle sudden spikes in traffic.

Amazon SQS FIFO queuesensure that orders are processed in the exact order received and maintain message deduplication.

AWS Lambdascales automatically, handling bursts and maintaining high availability in a cost-effective manner.

Option A and D:Amazon SNS does not guarantee ordered processing.

Option C:Standard SQS queues do not guarantee order.

AWS Documentation References:

Amazon SQS FIFO Queues

EBS gp3 volumes allow you to independently configure IOPS and throughput, up to 16,000 IOPS, regardless of the volume size, and at a lower cost compared to io1/io2 provisioned IOPS volumes. This meets the requirement for cost-effective, predictable IOPS performance for Amazon RDS for PostgreSQL.

AWS Documentation Extract:

"With gp3 volumes, you can provision performance independent of storage capacity, up to 16,000 IOPS. This allows for cost-effective scaling for applications that require high performance at a lower price point compared to io1."

(Source: Amazon EBS documentation, gp3 Volumes)

A: gp2 ties IOPS to volume size; 5 TiB is wasteful if only 15,000 IOPS are needed.

B: io1 works but is significantly more expensive than gp3 for most workloads.

D: Magnetic volumes do not support high IOPS.

For improving availability and performance of the hybrid application, the following solutions are optimal:

AWS Global Accelerator (Option A): Global Accelerator provides high availability and improves performance by using the AWS global network to route user traffic to the nearest healthy endpoint (across AWS Regions). By adding the Network Load Balancers as endpoints, Global Accelerator ensures that traffic is routed efficiently to the closest endpoint, improving both availability and performance.

Network Load Balancer (Option D): Thestateful TCP-based workloadhosted on Amazon EC2 instances and thestateless UDP-based workloadhosted on-premises are best served by Network Load Balancers (NLBs). NLBs are designed to handle TCP and UDP traffic with ultra-low latency and can route traffic to both EC2 and on-premises endpoints.

Option B (CloudFront and Route 53): CloudFront is better suited for HTTP/HTTPS workloads, not for TCP/UDP-based applications.

Option C (ALB): Application Load Balancers do not support the stateless UDP-based workload, making NLBs the better choice for both TCP and UDP.

AWS References:

AWS Global Accelerator

Network Load Balancer

AWS Lambda supports encrypting environment variables at rest using AWS KMS. You can use encryption helpers (or Lambda’s built-in support) to encrypt sensitive environment variable values using a KMS key. These encrypted variables are not visible in plaintext to developers, either in the console or when running the code.

AWS Documentation Extract:

"AWS Lambda automatically encrypts environment variables at rest. For additional security, you can use AWS KMS keys and encryption helpers to encrypt environment variables, ensuring they are never exposed in plaintext."

(Source: AWS Lambda documentation, Environment Variables Security)

A: Does not address the issue (and adds more management overhead).

B, C: There is no native support for environment variable encryption via CloudHSM or ACM.

To send data privately from on-premises to S3 buckets across multiple AWS accounts:

A: Using AWS Direct Connect with a private virtual interface (VIF) enables private connectivity from on-premises into the VPC.

E: After establishing the central VPC in a networking account, use VPC peering to allow access to S3 buckets across multiple AWS accounts.

“Direct Connect private virtual interface (VIF) allows private IP connectivity to VPC resources.”

“VPC Peering enables routing of traffic between VPCs using private IP addresses.”

— AWS Direct Connect Documentation

— VPC Peering Guide

Why not others:

B: Public VIF sends traffic over public AWS services—not fully private.

C: Interface endpoint is useful within a single account/VPC context.

D: Gateway endpoint doesn't solve inter-account routing.

The AWS Cost and Usage Report (CUR) delivers detailed, line-item billing data to Amazon S3. AWS recommends querying CUR with Amazon Athena by creating external tables over the CUR S3 location (partitioned by time) to produce daily cost aggregations such as NAT Gateway (EC2:NatGateway) usage and cost. Amazon QuickSight natively connects to Athena as a data source to build and share dashboards with visuals (tables, time series) filtered from the start of the current month. DataSync (A, C) is a file transfer service and cannot query data. CloudWatch dashboards (C, D) visualize metrics/logs, not CUR datasets. Therefore, using Athena to query CUR and QuickSight to present a daily NAT gateway cost dashboard is the most direct and operationally efficient approach.

Deploying the web application on EC2 instances in private subnets behind an internal ALB ensures that the application is not directly accessible from the internet. By setting up a Site-to-Site VPN connection, the application can be accessed securely from the company's office network. Deploying NAT gateways in public subnets allows instances in private subnets to initiate outbound connections to the internet for downloading security patches.

TheGateway Load Balancer (GWLB)is specifically designed to route traffic through a security appliance in a hub-and-spoke model, making it the ideal solution for inspecting traffic between multiple AWS accounts. GWLB enables you to simplify, scale, and deploy third-party virtual appliances transparently, and it can work across multiple VPCs or accounts using interface endpoints (Gateway Load Balancer Endpoints).

Key AWS features:

Traffic Inspection: The GWLB allows the centralized security appliance to inspect traffic between different VPCs, making it suitable for inspecting inter-account interactions.

Interface VPC Endpoints: By using interface endpoints in the application accounts, traffic can securely and efficiently be routed to the security appliance in the networking account.

AWS Documentation: The use of GWLB aligns with AWS’s best practices for centralized network security, simplifying architecture and reducing operational complexity​.

The most secure solution for allowing EC2 instances to access an S3 bucket is by usingIAM roles. An IAM role can be created with an access policy that grants the required permissions (e.g., to read and write to the S3 bucket). The IAM role is then associated with the EC2 instances through anIAM instance profile.

By associating the role with the instances, the EC2 instances can securely assume the role and receive temporary credentials via the instance metadata service. This avoids the need to store credentials (such as access keys) on the instances or within the application, enhancing security and reducing the risk of credentials being exposed.

AWS CloudFormation can be used to automate the creation of the entire infrastructure, including EC2 instances, IAM roles, and associated policies.

AWS References:

IAM Roles for EC2 Instancesoutlines the use of IAM roles for secure access to AWS services.

AWS CloudFormation User Guidedetails how to create and manage resources using CloudFormation templates.

Why the other options are incorrect:

A. Save IAM access key in UserData: This is insecure because it involves storing long-term credentials in the instance user data, which can be exposed.

B. Store access keys in S3: This is also insecure, as it involves managing and distributing long-term credentials, which should be avoided.

D. Retrieve access keys via a script: This approach is unnecessarily complex and less secure than using IAM roles, which provide temporary credentials automatically.

Amazon RDS for MySQL supports the creation of read replicas, which are read-only copies of the primary database instance. By offloading read-heavy operations, such as reporting queries, to a read replica:

Performance Improvement: The primary DB instance is relieved from the additional load, reducing the likelihood of timeouts during order processing.

Data Consistency: Read replicas use asynchronous replication, ensuring that they have up-to-date data for accurate reporting.

Scalability: Multiple read replicas can be created to handle increased read traffic.

This approach allows employees to continue running necessary reports without impacting the performance of the ordering application.

Aurora PostgreSQL supports the pgvector extension, which allows storage and querying of vector embeddings directly inside the database. This eliminates the need for external vector databases and provides cost-effective and performant integration for AI workloads.