SAA-C03 Sample Questions Answers

Edge-Optimized API: Designed for global users by routing requests through CloudFront's edge locations, reducing latency.

Content Encoding: Enabling content encoding compresses data, further optimizing performance by decreasing payload size.

Caching: Adding API Gateway caching reduces the number of calls to Lambda and database backends, improving latency.

Reserved Concurrency: Although useful, this does not directly affect latency for transferring static and dynamic content.

AWS API Gateway Edge-Optimized APIs Documentation

AWS documentation states that Amazon Macie is the managed service designed to automatically identify and classify sensitive data stored in Amazon S3, including PII and healthcare-related identifiers.

Storing logs in Amazon S3 provides scalable, durable storage, and Amazon Athena can directly query JSON data stored in S3 using SQL.

Amazon Inspector (Option D) is for vulnerability scanning and does not identify sensitive data. DynamoDB with KMS (Option C) cannot detect sensitive information. EBS (Option B) requires custom tooling and does not support serverless SQL querying.

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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.

To break down consolidated billing costs by “product line” using tags, the company must use cost allocation tags and ensure those tags are activated for billing at the payer/management level. Because the teams have already applied user-defined tags to the compute resources across accounts, the correct approach is to (1) use those user-defined tags in the billing tools and (2) activate them so they appear in cost and usage reporting for consolidated billing.

B is required because cost reporting by product line depends on selecting the user-defined cost allocation tag key (for example, ProductLine=...) in AWS billing and cost management tooling (such as Cost Explorer reports). AWS-generated tags are not what teams typically use for chargeback by business dimension, and the scenario explicitly says teams tagged resources (i.e., user-defined).

E is required because in an AWS Organizations consolidated billing setup, cost allocation tag activation is handled centrally from the Organizations management account so that the tags can be used consistently in consolidated cost views and reporting. Activating tags centrally ensures the billing system recognizes and includes those tag dimensions in cost allocation data.

Option C is not relevant to billing breakdown; Resource Groups is for organizing and operating on resources, not for consolidated billing allocation. Option D is unnecessary in this scenario’s intended best practice because activation for consolidated billing reporting is done from the management account to standardize reporting. In short, you tag resources (already done), then activate the tag for billing and use it in billing reports to see cost by product line across accounts and Regions.

Therefore, B and E together meet the requirement with the correct billing-focused steps.

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.

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.

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.

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

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.

Application Load Balancer (ALB): ALB is suitable for routing HTTP/HTTPS traffic to the application servers. It provides advanced routing features and integrates well with Auto Scaling groups.

Target Group Configuration:

Create a target group for the application servers and register the Auto Scaling group with this target group.

Configure the ALB to forward requests from the web servers to the application servers.

Security Group Setup:

Configure the security group of the application servers to only allow traffic from the web servers' security group.

This ensures that only the web servers can access the application servers, meeting the requirement to limit access.

Benefits:

Security: Using security groups to restrict access ensures a secure environment where only intended traffic is allowed.

Scalability: ALB works seamlessly with Auto Scaling groups, ensuring the application can handle varying loads efficiently.

To ensure ALB access only via CloudFront, AWS prescribes restricting the origin to traffic from CloudFront. For ALB origins, the standard pattern is to allow inbound to the ALB only from CloudFront edge IP ranges using security groups or ALB listener rules. Network ACLs are coarse and stateless and add operational burden. CloudFront does not have a “VPC origin” object; instead, CloudFront references the ALB DNS name. By limiting the ALB’s security group to CloudFront IP ranges, direct client access to the ALB is blocked while CloudFront remains permitted. This aligns with security best practices to “restrict origin access to only CloudFront” and use SGs for instance/ALB layer controls.

For high availability, Amazon ElastiCache for Redis supports Multi-AZ with automatic failover, which provides primary and replica nodes in different Availability Zones. If the primary node fails, Redis automatically promotes a replica to primary.

From AWS Documentation:

“When you enable Multi-AZ with automatic failover, Amazon ElastiCache automatically detects failures and promotes a read replica to primary with minimal downtime.”

(Source: Amazon ElastiCache for Redis User Guide)

Why B is correct:

Multi-AZ provides automatic failover and data replication.

Ensures continuous availability and protects against node or AZ failures.

Fully managed with no manual intervention needed.

Why others are incorrect:

A: Manual promotion is not automatic.

C & D: Restoring from backup is slow and meant for disaster recovery, not failover.

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

The Kubernetes Horizontal Pod Autoscaler (HPA) scales pods, not nodes. When the cluster runs out of node capacity, the HPA cannot schedule more pods.

On Amazon EKS, AWS recommends using the Kubernetes Cluster Autoscaler to automatically adjust the number of nodes in the cluster’s underlying Auto Scaling group based on pending pods.

Cluster Autoscaler watches for pods that cannot be scheduled because of insufficient resources and then scales out nodes automatically with minimal administrative overhead. It also scales in nodes when they are underutilized.

Why others are not correct:

A: Just tracking memory usage does not automatically scale nodes or integrate with Kubernetes scheduling.

C: A custom Lambda-based resizer is unnecessary undifferentiated heavy lifting compared to the native Cluster Autoscaler.

D: An Auto Scaling group is already typically used under EKS, but by itself it does not respond to pod scheduling pressure without Cluster Autoscaler.

To enable DNS resolution from AWS VPCs to on-premises DNS servers over Direct Connect or VPN, AWS recommends using Amazon Route 53 Resolver with outbound endpoints. An outbound endpoint allows DNS queries originating in the VPC to be forwarded to a customer-managed DNS server (e.g., on-prem).

Next, a forwarding rule (Forward type) must be created to forward DNS queries for the custom domain internal.example.com to the on-premises DNS IP addresses. This rule defines what domain names are forwarded and to which DNS servers.

Finally, the rule must be associated with all workload VPCs to allow those VPCs to use the rule. There is no need to deploy endpoints in every VPC — one outbound endpoint is sufficient and can be shared across VPCs via rule association.

???? Reference:

Route 53 Resolver Endpoints

Best practices for hybrid DNS resolution

Encryption at Rest: AWS Key Management Service (AWS KMS) provides centralized control over the cryptographic keys used to protect data. By using AWS KMS with Amazon S3, you can manage encryption keys and define policies to control access to them.

Encryption in Transit: By enforcing the aws:SecureTransport condition in the S3 bucket policy, you ensure that all data is transmitted over HTTPS, protecting data in transit.

Access Control: IAM policies allow you to define fine-grained permissions for users and roles, ensuring that only authorized entities can access the customer records.

Monitoring: AWS CloudTrail provides a record of actions taken by a user, role, or AWS service in Amazon S3, enabling you to monitor access to the records.

For short, frequent daily spikes (15–20 minutes), the most cost-effective scaling behavior typically comes from target tracking scaling driven by a request-based metric, because it continuously adjusts capacity to maintain a chosen target value rather than adding/removing capacity in coarse steps. Option D uses a custom CloudWatch metric representing the number of GET requests (sourced from ALB access logs, application instrumentation, or request counting logic) and applies target tracking so the Auto Scaling group scales out and in proportionally to demand. This helps avoid both under-provisioning (bad performance during spikes) and over-provisioning (wasted cost between spikes), which is exactly what cost-optimized elasticity aims for.

Option A (simple scaling) is usually less cost-efficient for bursty traffic because it relies on fixed adjustments and alarm thresholds, often with cooldowns. With 15–20 minute spikes, simple scaling can react too slowly, overshoot, or oscillate, leaving extra instances running after the spike or failing to ramp fast enough at the start. Option B (predictive scaling) is intended for regular, forecastable demand patterns, but it’s not always the most cost-effective choice for repeated short spikes because it can pre-scale conservatively and may require more historical data and tuning; it is often paired with dynamic scaling anyway. Option C uses UnhealthyHostCount, which is a health signal—not a demand signal—and scaling on unhealthy hosts can increase cost without addressing request volume; it may also mask underlying application issues rather than scaling to meet load.

Because the requirement explicitly allows standard or custom metrics and focuses on scaling based on request volume, D best matches a cost-efficient, responsive approach that directly tracks incoming workload.

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 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.

Amazon RDS Proxy is a fully managed database proxy for RDS that makes applications more scalable, more resilient to database failures, and more secure. RDS Proxy pools and shares database connections, allowing applications to open and close connections as needed without overwhelming the database. This is the recommended solution when the application cannot be modified to use connection pooling itself.

AWS Documentation Extract:

"Amazon RDS Proxy helps manage database connections to improve application scalability and performance. It pools connections and shares them among application clients, which can mitigate issues caused by opening and closing many database connections."

(Source: Amazon RDS Proxy documentation)

A: Upgrading the instance does not solve connection inefficiency and can be cost-ineffective.

B: Increasing IOPS only helps if storage is a bottleneck, not if connections are the issue.

D: Multi-AZ improves availability, not connection management.

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.

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

Amazon RDS Proxy helps manage thousands of concurrent database connections by pooling and reusing them efficiently. It is especially useful for serverless applications like AWS Lambda that can open numerous connections quickly, potentially overwhelming the database. Using RDS Proxy reduces connection management overhead and improves fault tolerance.

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.

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 RDS for MySQL Reserved Instances provide significant savings over on-demand pricing when you plan to run the database for long periods. This is the most cost-effective option for non-production, long-running managed MySQL workloads.

Reference Extract:

"Reserved Instances provide a significant discount compared to On-Demand pricing and are recommended for steady-state workloads that run for an extended period."

Source: AWS Certified Solutions Architect – Official Study Guide, RDS Cost Optimization section.

AWS KMS with SSE-KMS provides granular key management and auditability. All use of KMS keys is logged in AWS CloudTrail, which allows compliance teams to monitor encryption and decryption operations. A bucket policy can be configured to enforce uploads only with the designated KMS key, ensuring that users cannot bypass encryption or change methods. Option A (SSE-S3 with bucket policy) enforces encryption but does not provide the same level of control or auditable key usage. Option C (client-side encryption) increases complexity and key management burden. Option D prevents bucket setting changes but does not prevent unencrypted uploads. Therefore, B ensures the most granular control, auditability, and compliance with financial data requirements.

Creating a listener rule on theApplication Load Balancer (ALB)to return a maintenance response during the maintenance window is the most straightforward solution with the least operational overhead. The rule can be configured to match all incoming requests and return a custom response, and it can be easily removed once maintenance is complete.

Option A (Aurora table flag): This adds unnecessary complexity for a temporary maintenance response.

Option B and D (SQS or SNS): These options introduce more components than needed for a simple maintenance message.

AWS References:

ALB Listener Rules

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

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.

Amazon Kinesis allows real-time ingestion of game events at scale, while Amazon DynamoDB provides millisecond-latency access to user data, automatically scaling with demand. This combination ensures real-time processing and fast data retrieval without managing infrastructure.

Amazon SQS FIFO queues guarantee the order of message delivery and ensure that each message is delivered exactly once. Paired with AWS Lambda, this creates a scalable, fault-tolerant architecture that processes each order in order and prevents duplicates, which is critical for ecommerce workflows.

Amazon EFS provides a fully managed, highly available, and shared file system that can be mounted by instances across multiple Availability Zones. This ensures consistency of files between EC2 instances and avoids replication issues. EBS volumes, in contrast, are AZ-scoped and not designed for multi-instance sharing. Options A and B rely on custom replication or manual file handling, which increases operational overhead and risks inconsistencies. Option D does not solve the shared access and consistency requirement. By migrating storage to EFS, both EC2 instances will read and write to the same storage system, ensuring that users always access the latest files without 404 errors.

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

AWS DataSync provides a fully managed, secure, and high-performance service for transferring large amounts of data between on-premises storage and Amazon S3. It uses TLS encryption in transit and automates data validation, scheduling, and monitoring.

From AWS Documentation:

“AWS DataSync securely and efficiently transfers large amounts of data online between on-premises storage and AWS services. All data is encrypted in transit using TLS.”

(Source: AWS DataSync User Guide – How DataSync Works)

Why B is correct:

Encrypts all data in transit automatically.

Optimized for high-throughput WAN environments (100 Mbps to multi-Gbps).

Fully managed, with no need to provision additional infrastructure.

Integrates natively with S3 and supports incremental syncs.

Why others are incorrect:

A: DMS is designed for database migration, not unstructured data.

C: Snowball is for offline migrations, not needed given available connectivity.

D: Direct Connect is costly for temporary data transfers and unnecessary here.

For bursty and seasonal workloads, AWS recommends serverless architectures using Amazon API Gateway + AWS Lambda:

API Gateway exposes a fully managed, scalable API endpoint.

Lambda provides automatic scaling based on request volume, with no need to provision or manage servers.

This is ideal for workloads with variable or seasonal demand, such as end-of-year tax computation bursts.

This combination minimizes operational overhead (no OS patching, no capacity planning) while scaling seamlessly to meet peak demand.

Options A, C, and D rely on EC2 instances. They require capacity planning, scaling configuration, and ongoing management. They do not scale as effortlessly as Lambda for unpredictable or highly seasonal workloads.

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.

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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Given the large size (180 TB) of the database and the time constraint,AWS Snowball Edge Storage Optimizedis the best solution. Snowball Edge allows for the physical transfer of large datasets to AWS efficiently without relying on slow internet connections.AWS DMSandSCTcan be used to perform ongoing replication of any changes made during the migration, ensuring minimal downtime.

Option B (VPN): Using a 100 Mbps internet connection would take far too long to transfer 180 TB.

Option C (Direct Connect): Establishing a 10 Gbps Direct Connect link might not be feasible within the 2-week timeframe.

Option D (DataSync over internet): With the existing internet connection, DataSync would also take too long.

AWS References:

AWS Snowball Edge

AWS DMS

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.

Option B: FSx for Lustre is designed for HPC workloads with high IOPS.

Option E: A cluster placement group ensures low-latency networking for HPC analytics workloads.

Option A: Amazon EFS is not optimized for HPC.

Option D: Mountpoint for S3 does not meet high IOPS needs.

This solution offers the most scalable and cost-effective approach with minimal changes to the existing web portal and no code modifications.

Amazon EC2 On-Demand Instances in an Auto Scaling Group: Running the web portal on EC2 On-Demand instances ensures 100% uptime and scalability. The Auto Scaling group will maintain the desired number of instances, automatically scaling up or down as needed, ensuring high availability for the employee web portal.

AWS Lambda for Document Extraction: Lambda is a serverless compute service that allows you to run code in response to events without provisioning or managing servers. By using Lambda to run the document extraction program, you can trigger the function whenever an employee uploads a document. This approach is cost-effective since you only pay for the compute time used by the Lambda function.

No Code Changes Required: This solution integrates with the existing infrastructure with minimal implementation effort and does not require any modifications to the web portal's code.

Why Not Other Options?:

Option B (Spot Instances): Spot Instances are not suitable for workloads requiring 100% uptime, as they can be terminated by AWS with short notice.

Option C (Savings Plan): A Savings Plan could reduce costs but does not address the requirement for running the document extraction program efficiently or without code changes.

Option D (S3 with API Gateway and Lambda): This would require significant changes to the existing web portal setup, including moving the portal to S3 and reconfiguring its architecture, which contradicts the requirement of minimal implementation effort and no code changes.

AWS References:

Amazon EC2 Auto Scaling- Information on how to use Auto Scaling for EC2 instances.

AWS Lambda- Overview of AWS Lambda and its use cases.

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.

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

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

AWS Documentation Extract:

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

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

Other options:

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

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

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

Detailed Explanation:

A. IAM identity provider:Does not support centralized management across multiple accounts.

B. AWS Managed AD:Unnecessary if an on-premises Active Directory already exists.

C. IAM Identity Center + Existing AD:Best approach to integrate existing Active Directory for SSO, with MFA and centralized permissions.

D. Lambda for synchronization:Adds complexity and does not leverage IAM Identity Center capabilities.

AWS KMS automatic key rotationis the simplest and most operationally efficient solution. Enabling automatic key rotation ensures that KMS automatically generates new key material for the key every year without requiring manual intervention.

Option B:Configuring alerts to rotate keys introduces operational overhead as the actual rotation must still be managed manually.

Option C:Scheduling a Lambda function to rotate keys adds unnecessary complexity compared to enabling automatic key rotation.

Option D:Using a CloudFormation stack to run a Lambda function for key rotation increases operational overhead and complexity unnecessarily.

AWS Documentation References:

AWS KMS Key Rotation

Using Customer-Managed Keys with Amazon RDS

Using Amazon SQS decouples the API from the database, allowing the system to handle write bursts without data loss. The queue buffers incoming requests, and AWS Lambda processes them asynchronously, writing to the RDS instance at a sustainable rate.

From AWS Documentation:

“Amazon SQS acts as a buffer between components that produce and consume data, allowing each to operate independently. You can use AWS Lambda to process messages from SQS and write them to other services such as Amazon RDS.”

(Source: Amazon SQS Developer Guide)

Why C is correct:

SQS absorbs write surges and ensures durable message retention.

Lambda scales automatically with message volume and reduces DB connections.

Prevents timeout errors by smoothing traffic spikes.

Why others are incorrect:

A: Scaling RDS vertically doesn’t address connection spikes.

B: Multi-AZ is for availability, not write throughput.

D: SNS is for fan-out message delivery, not queue-based buffering.

To ensure that log files are immutable and cannot be deleted or overwritten for a specified retention period, Amazon S3 offers Object Lock in Compliance Mode. When enabled:

Compliance Mode: Ensures that a protected object version can't be overwritten or deleted by any user, including the root user in your AWS account, for the duration of the retention period. AWS Documentation

S3 Versioning: Must be enabled on the bucket to use Object Lock. This allows multiple versions of an object to be stored, ensuring that previous versions are preserved and protected. Amazon Web Services, Inc.

By enabling S3 Versioning and applying Object Lock in Compliance Mode with a 1-year retention period, the company can meet regulatory requirements to retain log data securely and prevent any modifications or deletions during that time.

To handle temporary high workloads, Amazon RDS provisioned IOPS can be increased to meet the expected spike in database throughput.

Amazon EFS Elastic throughput mode is ideal for workloads with unpredictable or spiky traffic patterns. It automatically scales throughput based on the file system's size and activity, which is more effective than Bursting throughput during high sustained activity like a marketing campaign.

Multi-AZ improves availability but does not directly address performance. Migrating to PostgreSQL during a short campaign period introduces unnecessary complexity.

The requirement to “have access to the operating system” means the compute layer must be Amazon EC2 (or containers on EC2). Managed runtimes such as Lambda and Fargate do not provide OS-level access.

The requirement for a “low-latency NoSQL database” maps directly to Amazon DynamoDB, which is a fully managed NoSQL key-value and document database that provides single-digit millisecond latency at any scale.

Because the application runs in a private subnet, AWS best practice is to access DynamoDB privately via a VPC endpoint (gateway endpoint for DynamoDB). This avoids traversing the public internet and simplifies security.

An instance profile (EC2 role) is the recommended method to grant EC2 instances permission to access DynamoDB without hardcoding credentials.

Why the other options are not correct:

B: Lambda does not provide OS access, which violates the security requirement.

C: Fargate does not provide OS access, and Aurora PostgreSQL is a relational database, not NoSQL.

D: S3 + Athena is an analytics pattern, not a low-latency NoSQL database solution; query latency is much higher and not suitable for OLTP-style app storage.

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.

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.

To prevent loss of access to the AWS root user account due to a lost MFA device, AWS recommends enabling multiple MFA devices for the root user.

Multiple MFA Devices: AWS allows up to eight MFA devices (virtual, hardware, or security keys) to be associated with a single root user account. This redundancy ensures that if one device is lost, others can be used to authenticate and access the account.

Security Best Practices: Implementing multiple MFA devices enhances account security and provides resilience against potential access issues.

By proactively setting up multiple MFA devices, the company can maintain uninterrupted access to its critical AWS resources, even in the event of a lost or malfunctioning MFA device.

The most efficient way for management-style reporting is AWS Cost Explorer, because it is designed for interactive cost analysis, filtering, grouping, and exporting reports without building a data pipeline. If the organization has activated cost allocation capabilities (for example, by tagging resources or using other allocation methods), Cost Explorer can present costs in a way that supports chargeback/showback and budgeting. From an operational standpoint, generating and downloading a report from Cost Explorer is quick, requires minimal setup, and is repeatable for periodic budget planning.

Option A (Athena) is powerful but typically requires setting up the Cost and Usage Report (CUR) delivery to Amazon S3, defining schemas, and writing/maintaining SQL queries. That is more operational overhead than needed when the ask is “most efficient way to obtain this report information.” Option C (billing dashboard bill download) provides invoice-style line items, but it is not optimized for slicing/grouping “by user” and may not align with departmental budgeting workflows. Option D is unrelated: AWS Budgets alerts on thresholds and forecasts; it does not generate a billed-items-by-user report.

Important nuance: “by user” reporting in AWS is usually achieved through cost allocation tags, account structure, or other allocation dimensions rather than literal per-person IAM identity billing. In practice, departments/teams/users are mapped via tagging and chargeback structures, which Cost Explorer is intended to analyze and export. As a result, Cost Explorer is the most operationally efficient tool to produce a downloadable report for budget planning.

Therefore, B best meets the requirement with the least effort and fastest path to a usable report.

The company needs a cloud-based storage solution for frequently accessed data with low latency, while retaining their current on-premises infrastructure for some data storage. AWS Storage Gateway'sVolume Gateway with cached volumesis the most appropriate solution for this scenario.

AWS Storage Gateway - Volume Gateway (Cached Volumes):

Volume Gateway with cached volumesallows you to store frequently accessed data in the AWS Cloud while keeping the most recently accessed data cached locally on-premises. This ensures low-latency access to active data while providing scalability for the rest of the data in the cloud.

The cached volume option stores the primary data in Amazon S3 but caches frequently accessed data locally, ensuring fast access. This configuration is well-suited for applications that require fast access to frequently used data but can tolerate cloud-based storage for the rest.

Since the company is facing limited on-premises storage, cached volumes provide an ideal solution, as they reduce the need for additional on-premises storage infrastructure.

Why Not the Other Options?:

Option A (S3 File Gateway): S3 File Gateway provides a file-based interface (SMB/NFS) for storing data directly in S3. While it is great for file storage, the company’s need for block-level storage with iSCSI targets makes Volume Gateway a better fit.

Option C (Volume Gateway - Stored Volumes): Stored volumes keep all the data on-premises and asynchronously back up to AWS. This would not address the company's storage limitations since they would still need substantial on-premises storage.

Option D (Tape Gateway): Tape Gateway is designed for archiving and backup, not for frequently accessed low-latency data.

AWS References:

AWS Storage Gateway - Volume Gateway

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.

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 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.

AWS Backup is a fully managed backup service designed to centralize and automate data protection across AWS services including EC2 and RDS. It allows users to define backup schedules (backup plans) and automatically create and retain backups. AWS Backup also offers restore testing plans, allowing users to automate the validation of backups by restoring them in a controlled manner. This service is built to minimize operational overhead by removing the need to manage custom scripts, manual processes, or additional orchestration services. This aligns with AWS best practices for resilience, automation, and operational excellence.

Reference Extract from AWS Documentation / Study Guide:

"AWS Backup enables you to centralize and automate data protection across AWS services. You can create backup plans, schedule backups, and set lifecycle policies. AWS Backup also enables restore testing to verify your backup integrity, with minimal manual intervention."

Source: AWS Certified Solutions Architect – Official Study Guide, Resiliency and Disaster Recovery section; AWS Backup User Guide.

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 EC2 allows you to install and manage SQL Server directly on a Windows or Linux VM, giving you full access to the underlying operating system. This is required when you need to install custom agents, configure OS-level features, or have complete control over the environment.

Amazon RDS and Aurora are managed services and do not provide access to the underlying OS, nor does Redshift (which is a data warehouse, not SQL Server).

AWS Documentation Extract:

"If you require access to the underlying operating system or need to install custom software, use SQL Server on Amazon EC2. Amazon RDS is a managed service and does not provide OS-level access."

(Source: AWS Database Migration documentation, SQL Server Deployment Options)

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.

To meet the requirements, the key must support automatic rotation, and the company must be able to disable (deactivate) the key and schedule deletion. In AWS KMS, these lifecycle controls are available for customer managed keys. Automatic key rotation is supported for symmetric customer managed KMS keys used for encryption and decryption operations. When automatic rotation is enabled, AWS KMS generates new cryptographic material for the key on a regular schedule while the key ID remains the same, helping organizations meet compliance and security best practices without manual operational work.

Option C is the only choice that explicitly combines a symmetric customer managed key with automatic rotation enabled, which directly satisfies the rotation requirement. As a customer managed key, it can also be disabled (to prevent use) and scheduled for deletion (with a waiting period), meeting the rest of the lifecycle needs.

Option A is incorrect because automatic rotation is not generally available for asymmetric KMS keys in the same way; asymmetric keys are used for specialized use cases such as signing or asymmetric encryption, and rotation behavior differs. Options B and D mention “disabling envelope encryption,” which is not a configurable “option” you turn off in KMS; envelope encryption is a recommended pattern where KMS protects data keys, and services commonly use it under the hood. Those options therefore do not describe a valid configuration that meets the requirement.

Therefore, the correct solution is to create a symmetric customer managed KMS key and enable automatic rotation, while using standard KMS controls to disable and schedule deletion when required.

AWS Glue jobs are designed for extract, transform, and load (ETL) operations, which are perfect for transforming clinical trial data. AWS Glue integrates with AWS Key Management Service (KMS), allowing for customer-specific encryption keys, fulfilling the encryption requirement with minimal operational effort. Client-side encryption with AWS KMS ensures that the data is encrypted before it is sent to S3, aligning with the security needs specified in the scenario.

Key aspects:

AWS Glue: This managed ETL service simplifies data transformation, reduces operational overhead, and integrates seamlessly with KMS.

CSE-KMS: Client-side encryption with KMS ensures that the data is encrypted with customer-specific keys before it is processed or stored in S3, offering robust security​​.

Minimal Operational Overhead: Compared to managing an EMR cluster, AWS Glue automates much of the process, making it a lower-effort solution.

AWS Documentation: According to the AWS Well-Architected Framework, encryption with AWS KMS offers strong security controls that meet the needs of industries requiring high levels of confidentiality​​.

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.

When an AWS Lambda function is invoked, especially after periods of inactivity, it may experience cold starts that delay execution. As demand increases, the scaling behavior and latency of Lambda can affect performance. Provisioned Concurrency is an AWS feature designed specifically to solve this issue.

From AWS Documentation:

“Provisioned Concurrency keeps functions initialized and hyper-ready to respond in double-digit milliseconds.”

(Source: AWS Lambda Developer Guide – Managing Concurrency)

Why Option D is correct:

Provisioned Concurrency ensures that a specified number of Lambda function instances are always warm and ready to serve requests, eliminating cold start latency.

It's cost-effective for workloads with consistent usage patterns, like real-time simulations for a small user group.

Maintains scalability and low overhead of Lambda without moving to managed container or EC2 platforms.

Why the other options are less optimal:

Option A (Fargate) and Option B (EC2): Introduce more infrastructure and higher ongoing costs for a small team with likely intermittent usage.

Option C (AWS Batch): Ideal for batch jobs, not real-time simulations; also incurs higher latency due to job queuing.

For steady, predictable EC2 usage with potential changes in instance families over time, AWS recommends Savings Plans. Compute Savings Plans “apply to any EC2 instance regardless of region, instance family, operating system, or tenancy,” and also apply to AWS Fargate and AWS Lambda, delivering the most flexibility over a multi-year horizon. A 3-year term provides the highest discount among Savings Plans for long-lived workloads. EC2 Instance Savings Plans are limited to a chosen instance family in a region; as needs evolve (e.g., size or family changes), discounts may not fully apply. Spot Instances are not appropriate for long, interruption-sensitive jobs because Spot capacity can be reclaimed with short notice. Therefore, a Compute Savings Plan (3-year) best matches cost optimization with flexibility for growth and changes.

The company wants to reduce end-to-end load time for its global customer base.AWS Global Acceleratorprovides a network optimization service that reduces latency by routing traffic to the nearest AWS edge locations, improving the user experience for globally distributed customers.

AWS Global Accelerator:

Global Acceleratorimproves the performance of your applications by routing traffic through AWS’s global network infrastructure. This reduces the number of hops and latency compared to using the public internet.

By creating astandard acceleratorand configuring the existing NLBs as target endpoints, Global Accelerator ensures that traffic from users around the world is routed to the nearest AWS edge location and then through optimized paths to the NLBs in each region. This significantly improves end-to-end load time for global customers.

Why Not the Other Options?:

Option A (ALBs instead of NLBs): ALBs are designed for HTTP/HTTPS traffic and provide layer 7 features, but they wouldn’t solve the latency issue for a global customer base. The key problem here is latency, and Global Accelerator is specifically designed to address that.

Option B (Route 53 weighted routing): Route 53 can route traffic to different regions, but it doesn’t optimize network performance. It simply balances traffic between endpoints without improving latency.

Option C (Additional NLBs in more regions): This could potentially improve latency but would require setting up infrastructure in multiple regions. Global Accelerator is a simpler and more efficient solution that leverages AWS’s existing global network.

AWS References:

AWS Global Accelerator

By usingAWS Global Acceleratorwith the existing NLBs, the company can optimize global traffic routing and improve the customer experience by minimizing latency. Therefore,Option Dis the correct answer.

To track costs by department, you must activate the custom department tag as a cost allocation tag in the AWS Organizations management account. Once activated, Cost Explorer and cost and usage reports can group costs by this tag for all linked accounts. The most operationally efficient way is to activate only the relevant department tag and create a cost and usage report grouped by that tag.

AWS Documentation Extract:

“To use a tag for cost allocation, you must activate it in the AWS Billing and Cost Management console. After activation, you can use the tag to group costs in Cost Explorer and reports.”

(Source: AWS Cost Management documentation)

A, E: aws:createdBy is not related to department cost grouping and is unnecessary.

B: Applying extra filters is optional; D is more direct and operationally efficient.

AWS Budgets allows you to set custom cost and usage budgets. When actual or forecasted usage exceeds the threshold, AWS Budgets can automatically send alerts to an Amazon SNS topic. You can use AWS Cost Explorer in parallel for visual tracking of spending. This solution requires no code and has minimal operational overhead.

AWS Fargate runs containers without managing servers, and ECS Service Auto Scaling adjusts the number of tasks based on demand. Behind an Application Load Balancer, ECS services elastically scale out to handle concurrent long-running requests. This fits workloads with processing times of 5–20 minutes per request. Lambda (C, D) has a maximum 15-minute timeout, so a portion of requests would fail or require complex refactoring and orchestration. Option B relies on vertical scaling and manual intervention, leaving capacity idle and failing to scale automatically with spikes. By containerizing the app and running on ECS with Fargate, the company gains automatic scaling, isolation per task, and no instance management, ensuring reliable throughput as request volume grows while keeping operations minimal.

The company wants to move from an on-premises Docker environment to fully managed AWS services with persistent storage. The best fit is:

Amazon ECS with AWS Fargate launch type: This is a serverless container orchestration solution where AWS manages the underlying infrastructure, removing the need to manage EC2 or Kubernetes nodes.

Amazon EFS (Elastic File System): This is a fully managed, scalable, and shared file system for use with ECS tasks. It supports persistent storage for containers, replacing the local volumes used on-premises.

This combination (ECS + Fargate + EFS) is fully managed and requires no manual server maintenance.

Option A uses EKS with self-managed nodes, which is not fully managed.

Option C (DynamoDB) is for structured key-value storage, not for persistent file storage.

Option D uses ECS with EC2 launch type, which is not serverless and requires managing instances.

???? Reference:

Using Amazon ECS with AWS Fargate

Mounting EFS volumes in ECS tasks

Explanation (AWS Docs):

A: Use Direct Connect with a private VIF to ensure private connectivity from on-premises to AWS.

E: Peer the networking VPC with VPCs in the accounts hosting S3 buckets to allow private routing.

“A private virtual interface enables private connectivity to your VPC.”

— Direct Connect Private VIF

The most secure and least operationally intensive method is to configure cross-account access using resource-based policies on the S3 bucket. This allows trusted external AWS accounts (consulting agencies) to securely access the S3 data without the need to manage user credentials or build additional infrastructure.

Options A and B pose security risks. Option D increases operational complexity and violates least privilege by managing external users inside your AWS account.

AWS recommends Auto Scaling with dynamic scaling policies to handle unpredictable workload spikes. Target tracking scaling policies automatically adjust capacity based on defined metrics such as average CPU utilization or request count per target. This approach ensures applications maintain responsiveness without overprovisioning. Scheduled scaling (options B and C) is only effective when traffic patterns are predictable, which is not the case here. Reserved Instances or Spot Instances also do not address sudden demand changes effectively. Replacing the ALB with an NLB (D) does not solve latency caused by EC2 instance capacity. Therefore, using EC2 instances in an Auto Scaling group with a target tracking scaling policy is the most effective and cost-efficient solution for unpredictable, short-lived traffic spikes.

Amazon S3 Access Points simplify managing data access for shared datasets in S3 by allowing the creation of distinct access policies for different applications or users. Each access point has its own policy and can be managed independently. This method avoids overloading a single bucket policy and helps remain within policy size limits.

Option D provides a scalable and operationally efficient solution by offloading individual access controls from a central bucket policy to individually managed access points, which is ideal for environments with many consuming applications.

For globally distributed consumers of REST APIs, API Gateway edge-optimized endpoints “route requests to the nearest CloudFront edge location, which then forwards them to your API in the [home] Region,” reducing latency for users worldwide and scaling automatically for unknown or spiky traffic. By contrast, Regional endpoints are intended for clients within the same or nearby Region and do not provide global edge acceleration. AWS Lambda provides automatic scaling for serverless backends; latency can be further reduced by right-sizing memory (which also increases CPU) and, when needed, enabling provisioned concurrency to keep functions initialized and eliminate cold starts for critical paths. Using NLBs across Regions is not serverless and adds operational complexity without CloudFront edge acceleration. Therefore, combining API Gateway edge-optimized REST APIs with Lambda meets the requirements of minimal global latency and unknown initial traffic.

AWS Snowball Edge is specifically designed for use cases that involve limited or unreliable network connectivity. It enables data transfer and local compute processing at edge locations.

It comes in two options: Snowball Edge Storage Optimized and Snowball Edge Compute Optimized.

The Compute Optimized model allows the disaster response team to both store images locally and process data on the device using Amazon EC2-compatible compute resources.

This removes the need for constant network connectivity. After processing, the device can be shipped back to AWS, where data is uploaded to S3.

Other options fail due to:

SQS not being suitable for large binary image data (Option B)

Kinesis Data Firehose needing steady connectivity (Option C)

Storage Gateway is for hybrid cloud environments with ongoing connection, not rugged field use (Option D)

???? References:

AWS Snowball Edge Overview

Snowball Edge Use Cases

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

To ensure container images are secure and to notify administrators about vulnerabilities, the solution needs (1) a vulnerability scanning capability for container images and (2) a notification mechanism that alerts when findings occur. Amazon Inspector provides automated security assessments and can scan container images stored in Amazon ECR to identify software vulnerabilities and unintended network exposure patterns, producing findings that can be acted upon. Therefore, D addresses the core requirement of detecting vulnerabilities in container images.

To notify administrators with minimal custom work, AWS Config can help by evaluating resources against desired configurations and integrating with notifications through AWS services (for example, via Amazon SNS using Config rules/conformance packs). Using the AWS Config conformance pack for Amazon ECS helps establish a managed set of compliance checks aligned to ECS-related best practices. While Inspector is the system that detects vulnerabilities, Config can be used to enforce and monitor governance controls around the container environment and can trigger notifications when noncompliance is detected. In exam patterns, pairing an Inspector detection capability with a managed governance/notification framework like Config is a common “two-part” answer.

The other options do not meet the requirement: A (privileged mode) can increase risk rather than improve image security; logging does not equal vulnerability detection. C is unrelated because AWS WAF protects web applications at the edge and does not scan container images for CVEs. E is incorrect because Parameter Store stores configuration data and secrets; it does not encrypt container images (ECR encryption at rest is handled by AWS-managed mechanisms and KMS integration, not Parameter Store).

So D provides scanning and B supports managed compliance/notification controls with low operational overhead.

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.

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

Why Option B is Correct:

Amazon SQS: Ensures no requests are lost, even during traffic spikes.

API Gateway: Handles dynamic traffic patterns efficiently, integrating with SQS for asynchronous processing.

Lambda: Polls the queue and processes requests in a serverless and scalable manner.

Dead-Letter Queue (DLQ): Ensures failed messages are retried or logged for debugging.

Why Other Options Are Not Ideal:

Option A: Elastic Beanstalk cannot handle queue-based decoupling, making it unsuitable for spiky traffic.

Option C: ALB to Lambda does not provide buffering for traffic spikes, risking request loss.

Option D: SNS is better suited for notifications, not reliable for ensuring message durability.

AWS References:

Amazon SQS:AWS Documentation - SQS

The most cost-effective, secure way for private subnets to access AWS services without public IP addresses is to use VPC endpoints:

Interface endpoints (powered by AWS PrivateLink) for services like S3, DynamoDB, etc.

Traffic stays on the AWS network.

“You can privately connect your VPC to supported AWS services using interface VPC endpoints powered by AWS PrivateLink. Instances in your VPC do not require public IP addresses.”

— VPC Endpoints Documentation

Why not others:

NAT gateways incur hourly + data transfer costs and use public IPs.

Internet gateways expose traffic to the internet.

Direct Connect is for private on-prem connectivity, not needed here.

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.

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.

TooManyRequestsException errors occur when Lambda exceeds concurrency limits. The recommended pattern is to use Amazon SQS with Lambda to decouple and buffer traffic, ensuring that bursts of requests are queued and processed smoothly. Enabling provisioned concurrency for Lambda ensures that functions are pre-initialized and ready to handle spikes in load with low latency. Step Functions (B) is designed for workflow orchestration, not high-throughput request buffering. SNS with Lambda (C) does not provide buffering and may overwhelm Lambda during bursts. Reserved concurrency (D) limits function scaling instead of improving resilience. Therefore, option A provides a scalable and resilient solution, minimizing errors during traffic surges.

Amazon Rekognition provides pretrained models that can detect inappropriate or unsafe content (such as nudity or violence) without requiring users to build their own ML models. Using a Lambda function to call Rekognition when new photos are uploaded is a serverless and scalable solution.

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

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."

The least operational overhead approach is to use AWS Directory Service with AWS Managed Microsoft AD and establish a trust relationship with the existing on-premises Microsoft Active Directory. This pattern lets employees continue using their existing corporate credentials while AWS operates the directory infrastructure (patching, monitoring, availability, and domain controller management), reducing the burden compared to building and maintaining custom federation components. With a trust in place, identities and group memberships from the on-premises directory can be used for authentication and authorization workflows in AWS.

To provide role-based access to AWS resources and the AWS Management Console, users should assume IAM roles that grant permissions based on job function. IAM roles with appropriate trust policies enable temporary credentials and least-privilege access without creating long-lived IAM users for every employee. This aligns with AWS best practices of centralized identity management and using roles for access control.

Option B is not a standard direct integration pattern: IAM does not “LDAP bind” directly to on-premises AD for console access. Option C can work (custom identity broker + STS) but increases operational overhead because the company must build, secure, operate, and maintain the broker, including availability, updates, and incident response. Option D is not the typical solution for employee console federation from AD; Amazon Cognito is primarily aimed at customer identity and application sign-in, not as the primary mechanism for workforce console access to AWS accounts.

Therefore, A provides the required federation with the smallest operational footprint while supporting role-based access control.

A VPC gateway endpoint for Amazon S3 enables private connectivity to S3 without routing traffic through a NAT gateway or over the internet, eliminating NAT gateway costs. This solution is secure and redundant, as S3 endpoints are highly available by design.

AWS Documentation Extract:

"A gateway VPC endpoint enables you to privately connect your VPC to supported AWS services without requiring a NAT gateway or internet gateway."

(Source: Amazon VPC documentation, Gateway Endpoints)

A: NAT instances still incur operational overhead and costs.

B: Internet gateway exposes resources and does not provide private access.

D: Direct Connect is for hybrid networking, not for cost-efficient S3 access.

Amazon RDS Proxy is designed to manage a large number of database connections from applications, especially serverless applications that can scale quickly. It improves application availability and scalability by pooling and sharing established database connections. This reduces the overhead of database connections and prevents overload during traffic spikes.

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.

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

The requirements specify capturing unpredictable and sudden spikes in customer activity, integrating easily with other web applications, and including authorization.

Amazon API Gateway with Lambda authorizer provides a secure, scalable entry point with flexible authorization mechanisms including token validation.

Amazon Kinesis Data Firehose is a fully managed service to reliably load streaming data into destinations such as Amazon S3, which fits well for capturing streaming customer activity data.

API Gateway integrates natively with Firehose for direct ingestion.

This combination supports unpredictable traffic, smooth scaling, and simple authorization.

Option B uses Kinesis Data Streams, which requires more management than Firehose and is less optimized for direct API integration. Options A and D use Gateway Load Balancer and ECS containers plus EFS, which add complexity and are less suited for unpredictable traffic with integrated authorization.

Amazon SQS supports Interface VPC endpoints (AWS PrivateLink), enabling private connectivity from your VPC to SQS without using public IPs, traversing the public Internet, or requiring NAT/IGW. You can restrict access by attaching a queue resource policy that allows only the specific VPC endpoint and denies all other principals/paths, enforcing that all traffic stays on the AWS network. SSE-SQS (B) encrypts data at rest but does not influence network pathing. STS temporary credentials (C) handle authentication/authorization, not routing. VPC Flow Logs (D) are monitoring/visibility and do not prevent public egress. Creating an SQS VPC endpoint and tightening the queue policy satisfies the requirement of no public IP usage while maintaining secure, private access from serverless components in VPC subnets.

Comprehensive and Detailed Explanation (from AWS Solutions Architect documentation):

Amazon DynamoDB is a fully managed NoSQL database engineered for extremely high throughput and millisecond-level response times at any scale. It can automatically scale to support millions of requests per second and requires no management of infrastructure, storage provisioning, or server maintenance.

AWS documentation specifically highlights DynamoDB as the optimal solution for ecommerce workloads that require consistent low-latency performance, massive scalability, and near-zero operational overhead.

Aurora and RDS cannot support millions of requests per second, and Redshift is a data warehouse not intended for transactional workloads.

AWS Lambda is not suitable for long-running jobs that can take up to 20 minutes, as Lambda has a maximum execution duration of 15 minutes.

Amazon ECS with AWS Fargate allows you to run containers without managing EC2 instances, providing a scalable and highly available environment. You can scale Fargate tasks to handle large and parallel video processing jobs. Amazon Aurora is a highly available, managed relational database. S3 Intelligent-Tiering is cost-effective for storing large video files with variable access patterns.

AWS Documentation Extract:

"AWS Fargate lets you run containers without managing servers or clusters, providing a highly available and scalable compute environment. Fargate is suitable for running data processing workloads that require long-running compute tasks."

(Source: AWS Fargate documentation, Use Cases)

A: Lambda is not suitable for long-running (over 15 min) or heavy compute jobs.

C: Amazon EMR is optimized for big data analytics, not specific video processing. FSx for Lustre and Kinesis are not best fit for this use case.

D: EKS with EC2 adds operational overhead and RDS in a single AZ is not highly available; Glacier Deep Archive is not suitable for frequently accessed video files.

Latency-based routing in Amazon Route 53 is designed to route users to the Region that provides the lowest network latency, based on Amazon’s measurements of latency between AWS Regions and users’ networks. For applications deployed in multiple Regions, this provides the highest performance experience for global users.

Therefore, creating an A record with a latency routing policy is the correct choice.

Geolocation (Option B) routes based on user location, which may not always correspond to the lowest latency.

Failover (Option C) is for active-passive architectures, not performance optimization.

Geoproximity (Option D) is more complex and focused on directing traffic based on geographic bias rather than measured latency.

Aurora global database is specifically designed for cross-Region disaster recovery and low-latency global reads.

It provides:

Physical storage-level replication between Regions, typically with lag of under 1 second, easily satisfying RPO 1 minute.

Fast cross-Region failover capabilities, often within minutes or less, which meets the RTO 5 minutes requirement.

You configure the primary Region as the writer cluster and additional Regions (such as us-west-1) as secondary clusters with reader endpoints. In a disaster, you promote the secondary to be the new writer.

Why others are not correct:

A: Standard cross-Region read replicas for Aurora PostgreSQL do not provide automatic multi-Region failover with the same guarantees as Aurora global database and may not meet strict RTO/RPO requirements.

C: Logical replication and custom EventBridge failover is complex, error-prone, and higher overhead compared to the managed global database feature.

D: Restoring from snapshots plus cross-Region replication is too slow to meet RTO 5 minutes and certainly cannot maintain RPO 1 minute.

Key Requirements:

Protect public endpoints (CloudFront distributions and ALBs) frommalicious attacks.

Centralizedmanagementacross multiple accounts in an organization.

Ability tomonitor security configurationseffectively.

Minimizeoperational overhead.

Analysis of Options

Option A:

AWS WAF:Protects web applications by filtering and blocking malicious requests. Rules can be applied to both ALBs and CloudFront distributions.

AWS Firewall Manager:Enables centralized management of WAF rules across multiple accounts in an AWS Organizations organization. It simplifies rule deployment, avoiding the need to configure rules individually in each account.

AWS Config:Monitors compliance by using rules that check Regional and global WAF configurations. Ensures that security configurations align with organizational policies.

Operational Overhead:Centralized management and automated monitoring reduce the operational burden.

Correct Approach:Meets all requirements with the least overhead.

Option B:

This approach involves applying WAF rules in each account manually.

While AWS Config and AWS Security Hub provide monitoring capabilities, managing individual WAF configurations in multiple accounts introduces significant operational overhead.

Incorrect Approach:Higher overhead compared to centralized management with AWS Firewall Manager.

Option C:

Similar to Option A but includesAmazon Inspector, which is not designed for monitoring WAF configurations.

AWS Security Hubis appropriate for monitoring but is redundant when Firewall Manager and Config are already in use.

Incorrect Approach:Adds unnecessary complexity and does not focus on monitoring WAF specifically.

Option D:

AWS Shield Advanced:Focuses on mitigating large-scale DDoS attacks but does not provide the fine-grained web application protection offered by WAF.

AWS Config:Can monitor Shield Advanced configurations but does not fulfill the WAF monitoring requirements.

Incorrect Approach:Does not address the need for WAF or centralized rule management.

Why Option A is Correct

Protection:

AWS WAF provides fine-grained filtering and protection against SQL injection, cross-site scripting, and other web vulnerabilities.

Rules can be applied at both ALBs and CloudFront distributions, covering all public endpoints.

Centralized Management:

AWS Firewall Manager enables security teams to centrally define and manage WAF rules across all accounts in the organization.

Monitoring:

AWS Config ensures compliance with WAF configurations by checking rules and generating alerts for misconfigurations.

Operational Overhead:

Centralized management via Firewall Manager and automated compliance monitoring via AWS Config greatly reduce manual effort.

AWS Solution Architect References

AWS WAF Documentation

AWS Firewall Manager Documentation

AWS Config Best Practices

AWS Organizations Documentation

The issue described in the question, where incoming traffic seems to favor one EC2 instance, is often caused by session affinity (also known as sticky sessions) being enabled on the Application Load Balancer (ALB). When session affinity is enabled, the ALB routes requests from the same client to the same EC2 instance. This can cause an imbalance in traffic distribution, leading to performance bottlenecks on certain instances while others remain underutilized.

To resolve this issue, disabling session affinity ensures that the ALB distributes incoming traffic evenly across all EC2 instances, allowing better load distribution and reducing latency. The ALB will rely on its round-robin or least outstanding requests algorithm (depending on the configuration) to distribute traffic more evenly across instances.

Option B (Network Load Balancer): The NLB is designed for Layer 4 (TCP) traffic and low latency use cases, but it is not needed here as the problem is with load balancing logic at the application layer (Layer 7). The ALB is more appropriate for HTTP/HTTPS traffic.

Option C (Increase EC2 Instances): Adding more EC2 instances does not solve the root issue of uneven traffic distribution.

Option D (Health Check Frequency): Adjusting health check frequency won't address the imbalance caused by session affinity.

AWS References:

Application Load Balancer Sticky Sessions

Amazon Athenais a serverless query service that allows you to run SQL queries directly on data stored in Amazon S3 without the need for a data warehouse. It is cost-effective because you only pay for the queries you run, and it can handleApache Parquetfiles efficiently. Additionally, Athena integrates with KMS, making it suitable for querying encrypted data.

Key AWS features:

Cost-Effective: Athena charges only for the data scanned by the queries, making it a more cost-effective solution compared to Redshift or EMR for occasional queries.

Direct S3 Querying: Athena supports querying data directly in S3, including Parquet files, without needing to move the data.

AWS Documentation: Athena's compatibility with encrypted Parquet files in S3 makes it the ideal choice for this scenario, reducing both cost and complexity​​.

Pre-Signed URLs: Allow temporary access to S3 buckets, making it easy to manage time-limited upload permissions without complex operational overhead.

Lambda for Automation: Automatically generates and provides pre-signed URLs when users authenticate, minimizing manual steps and code complexity.

Least Operational Overhead: Requires no custom authentication service or deep integration with STS or Cognito.

Amazon S3 Pre-Signed URLs Documentation

AWS Storage Gateway stored volume gateway is designed for use cases where:

The primary data set remains on premises.

You want to maintain full local access to data with low latency.

You need asynchronous, secure replication and backup to AWS.

With stored volumes, you:

Map gateway storage volumes to local on-premises disks.

Present these volumes as iSCSI block devices to on-prem systems.

Storage Gateway then asynchronously backs up snapshots to Amazon S3, providing secure, durable offsite backup automatically.

Cached volume gateway (Option C) keeps the primary copy in AWS and only a subset cached locally, which does not meet the requirement to maintain full local access to all data.

Snowball and Snowball Edge (Options A and B) are primarily for bulk, one-time or periodic offline data transfer and do not provide an ongoing backup solution with continuous local access.

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.

Amazon RDS Multi-AZ deployment provides automated failover and increased availability for MySQL databases. In case of infrastructure failure or power outage in one Availability Zone, RDS automatically fails over to a standby replica in another AZ, minimizing downtime. This is the AWS-recommended way to achieve high availability for relational databases.

AWS Documentation Extract:

"Amazon RDS Multi-AZ deployments provide high availability, failover support, and data redundancy for database instances. In the event of infrastructure failure, Amazon RDS performs an automatic failover to the standby."

(Source: Amazon RDS documentation, High Availability)

A: An ALB does not increase availability for a single database instance.

B: EC2 instance recovery does not move the instance across Availability Zones.

D: Termination protection prevents accidental deletion, not availability issues.

AWS CloudFormationallows for the automated, repeatable setup of infrastructure, reducing human error and ensuring consistency.AWS Configprovides the ability to track changes in the infrastructure, ensuring that all changes are logged and auditable, which satisfies the requirement for tracking incremental changes.

Option A and C (AWS Organizations): AWS Organizations manage multiple accounts, but they are not designed for infrastructure setup or change tracking.

Option D (Service Catalog): Service Catalog is used for deploying products, not for setting up infrastructure or tracking changes.

AWS References:

AWS Config

AWS CloudFormation

Since the application uses long-lived TCP connections and must remain idle for up to 1 hour without timeout, all components involved in the connection path (ALB, GWLB, and firewall) must have their idle timeout values configured to at least 1 hour.

Gateway Load Balancer supports transparent insertion of firewalls, and configuring consistent idle timeouts ensures connections don’t drop mid-session.

Using just one firewall (option B) introduces a single point of failure. Increasing capacity (option D) doesn't solve idle timeout issues. Therefore, C provides a resilient and complete configuration.

Amazon EC2 On-Demand Instances: Since the batch jobs cannot be disrupted, On-Demand Instances provide the necessary reliability and availability.

Amazon S3 Standard: Storing data in S3 Standard for the first 30 days ensures quick and frequent access.

S3 Glacier Deep Archive: After 30 days, moving data to S3 Glacier Deep Archive significantly reduces storage costs for data that is rarely accessed.

S3 Lifecycle Configuration: Automating the transition and deletion of objects using lifecycle policies ensures cost optimization and compliance with data retention requirements.

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.

AWS Secrets Manager is designed specifically to securely store and manage sensitive information such as database credentials. It integrates seamlessly with AWS services like Lambda and RDS, and it provides automatic credential rotation with minimal operational overhead.

AWS Secrets Manager: By storing the database credentials in Secrets Manager, you ensure that the credentials are securely stored, encrypted, and managed. Secrets Manager provides a built-in mechanism to automatically rotate credentials at regular intervals (e.g., every 30 days), which helps in maintaining security best practices without requiring additional manual intervention.

Lambda Integration: The Lambda function can be easily configured to retrieve the credentials from Secrets Manager using the AWS SDK, ensuring that the credentials are accessed securely at runtime.

Why Not Other Options?:

Option A (Parameter Store with Rotation): While Parameter Store can store parameters securely, Secrets Manager is more tailored for secrets management and automatic rotation, offering more features and less operational overhead.

Option C (Encrypted Lambda environment variable): Storing credentials directly in Lambda environment variables, even when encrypted, requires custom code to manage rotation, which increases operational complexity.

Option D (KMS with automatic rotation): KMS is for managing encryption keys, not for storing and rotating secrets like database credentials. This option would require more custom implementation to manage credentials securely.

AWS References:

AWS Secrets Manager- Detailed documentation on how to store, manage, and rotate secrets using AWS Secrets Manager.

Using Secrets Manager with AWS Lambda- Guidance on integrating Secrets Manager with Lambda for secure credential management.

Using S3 gateway endpoints allows private and cost-free access to S3 without routing traffic through a NAT gateway. NAT gateway traffic incurs charges, especially when used across multiple Availability Zones.

By using an S3 gateway endpoint, EC2 instances in private subnets can access S3 directly without needing internet access, reducing both data transfer and NAT gateway costs.

Interface endpoints are more expensive and typically used for services like API Gateway or Systems Manager.

AWS Config is a service designed to assess, audit, and evaluate the configurations of AWS resources. It continuously monitors and records your AWS resource configurations and allows you to automate the evaluation of recorded configurations against desired configurations. By starting a configuration recorder, AWS Config will capture changes to supported resource types as configuration items—without the need to modify any of the existing resources. This provides a full history of configuration changes and is specifically intended for exactly this use case.

AWS Documentation Extract:

“AWS Config provides a detailed view of the configuration of AWS resources in your AWS account. This includes how the resources are related to one another and how they were configured in the past so you can see how the configurations and relationships change over time.”

“You can start the configuration recorder, which will record the configuration changes of the supported resources in your AWS account.”

(Source: AWS Config documentation, What is AWS Config?)

Other options:

B: CloudFormation drift detection only works for resources created and managed by CloudFormation and requires stacks.

C: Amazon Detective is used for analyzing and investigating security findings, not for resource configuration tracking.

D: AWS Audit Manager is used for automating evidence collection to help with audits, not for tracking resource configurations.

Amazon ECS with AWS Fargate provides serverless container compute that can scale tasks dynamically in response to demand. This matches the unpredictable scaling requirements of a gaming workload. Aurora Serverless v2 provides on-demand, autoscaling relational database capacity while supporting complex SQL queries. EC2 with Auto Scaling (A) works but requires significant management overhead. Lambda with DynamoDB (B) is not suitable because the workload requires a relational database and long-running processes. ParallelCluster with HPC (D) is designed for batch scientific workloads, not dynamic, interactive gaming. Option C provides the correct balance of elasticity, performance, and managed services for both compute and relational database needs.

Amazon S3 is the most scalable and cost-optimized object storage for large amounts of data. It integrates natively with Amazon SageMaker, which allows direct access to S3 data for machine learning training jobs without the need to copy data elsewhere. The S3 Intelligent-Tiering storage class further optimizes storage costs for data with unknown or changing access patterns, while maintaining immediate availability for ML training.

Copying to FSx for Lustre or EFS adds unnecessary complexity and cost unless ultra-high throughput POSIX file access is specifically required, which is not mentioned here.

AWS Documentation Extract:

"Amazon S3 provides cost-effective storage for ML data sets, and Amazon SageMaker can directly access data in S3. S3 Intelligent-Tiering automatically moves data between frequent and infrequent access tiers, optimizing costs for changing data access patterns."

(Source: AWS S3 and SageMaker documentation)

A, D: FSx for Lustre or EFS may be used in specialized cases but are not cost-optimized for general large-scale ML data storage.

C: SageMaker notebook instance storage is not designed for large-scale data ingestion or long-term storage.

AWS Step Functions supports long-running workflows and error retries, making it ideal for a job composed of many tasks. Integration with EventBridge allows automatic triggering from S3 events. This setup is resilient and supports up to 1-year execution duration.

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.

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.

AWS Secrets Manager natively supports automatic rotation of RDS for Oracle credentials, fully integrating with Amazon RDS. Rotation workflows are managed automatically by the service, eliminating custom scripting and reducing operational effort.

Migrating to EC2 (Option C) requires custom rotation logic. Converting to DynamoDB or Neptune (Options A and D) would require complete database redesign and do not fulfill the requirement to run Oracle.

This solution provides the most secure access for external support engineers with the least exposure to potential security risks.

AWS Systems Manager (SSM) and Session Manager: Systems Manager Session Manager allows secure and auditable access to EC2 instances without the need to open inbound SSH ports or manage SSH keys. This reduces the attack surface significantly. The SSM Agent must be installed and configured on all instances, and the instances must have an instance profile with the necessary IAM permissions to connect to Systems Manager.

IAM Identity Center: IAM Identity Center provides centralized management of access to the AWS Management Console for external support engineers. By using IAM Identity Center, youcan control console access securely and ensure that external engineers have the appropriate permissions based on their roles.

Why Not Other Options?:

Option B (Local IAM user credentials): This approach is less secure because it involves managing local IAM user credentials and does not leverage the centralized management and security benefits of IAM Identity Center.

Option C (Security group with SSH access): Allowing SSH access opens up the infrastructure to potential security risks, even when restricted by IP addresses. It also requires managing SSH keys, which can be cumbersome and less secure.

Option D (Bastion host): While a bastion host can secure SSH access, it still requires managing SSH keys and opening ports. This approach is less secure and more operationally intensive compared to using Session Manager.

AWS References:

AWS Systems Manager Session Manager- Documentation on using Session Manager for secure instance access.

AWS IAM Identity Center- Overview of IAM Identity Center and its capabilities for managing user access.

Versioning in S3 preserves every version of every object — preventing permanent overwrites. This ensures compliance where data cannot be overwritten or lost.

SSE-S3 ensures server-side encryption.

“When you enable versioning, Amazon S3 stores every version of every object. With versioning, you can preserve, retrieve, and restore every version of every object stored in an S3 bucket.”

— S3 Versioning

This satisfies regulatory requirements for protecting data from overwriting indefinitely.

Incorrect Options:

B: Object Lock with retention period is time-bound, not indefinite.

C: Legal hold blocks deletion but doesn’t directly prevent overwriting.

D: Storage Lens is analytics, not protection.

For processing thousands of images and generating large files while minimizing manual tasks and operational overhead, usingAWS Batchis the best solution. AWS Batch allows you to run large-scale, parallel, and managed batch computing jobs without needing to manage the underlying infrastructure.

AWS Batch: Automates the image processing jobs, dynamically allocating the necessary resources based on the job requirements, which reduces operational overhead.

AWS Step Functions: Orchestrates the entire image processing workflow, ensuring that tasks are executed in the correct sequence, improving manageability.

Amazon S3: Stores the processed files, providing scalable and cost-effective storage.

Option A (ECS with EC2 Spot Instances): While cost-effective, managing ECS and Spot Instances involves more operational effort.

Option C (Lambda with EC2 Spot): Lambda functions have size and duration limitations, making them less suited for large image processing tasks.

Option D (EC2 with Step Functions): Managing EC2 instances involves more overhead than using AWS Batch.

AWS References:

AWS Batch

AWS Step Functions

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.

Purchasing a Compute Savings Plan for the minimum baseline usage ensures cost savings. Using On-Demand Instances for peak times ensures flexibility without over-provisioning. S3 Lifecycle policies enable automatic transition of objects to lower-cost storage classes such as S3 Glacier orS3 Intelligent-Tiering, further reducing storage costs.

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.

AWS Compute Optimizerprovides detailed recommendations for optimizingAmazon EBS volumes, including insights into underutilized volumes, inefficient configurations, and potential cost savings. It analyzes usage patterns and provides recommendations based on historical data, making it the ideal tool for this use case.

Option A (Amazon Inspector): Amazon Inspector is for security assessments, not for cost optimization.

Option B (Systems Manager): Systems Manager does not specifically provide EBS optimization recommendations.

Option C (CloudWatch): CloudWatch metrics help monitor usage but do not offer optimization recommendations like Compute Optimizer.

AWS References:

AWS Compute Optimizer

End-to-end encryption means TLS is used not only from the client to the ALB, but also from the ALB to the EC2 targets. The least operational effort is achieved by using AWS Certificate Manager (ACM) Amazon-issued certificates where possible, because ACM automates key management, certificate provisioning, and renewal for supported use cases. Associating an ACM certificate with the ALB is a standard managed approach for TLS termination at the load balancer, and using managed certificates reduces the overhead of tracking expiration, renewing, and distributing certificates.

For encryption on the backend connection (ALB to instances), the instances must present a certificate and complete TLS. Using Amazon-issued ACM certificates (via supported mechanisms) reduces manual certificate lifecycle work compared with importing and managing third-party certificates. By avoiding third-party cert procurement and manual renewals, the solution minimizes ongoing operations and reduces the risk of outages due to expired certificates. This aligns with the requirement for the least operational effort while meeting the security requirement.

Option A is far more operationally heavy: CloudHSM is intended for scenarios requiring customer-managed HSMs and adds complexity in deployment, scaling, integration, and operations. Option B introduces self-signed certificates on instances, which increases operational friction (distribution, trust, rotation) and is not as clean for managed operations. Option C works but requires managing third-party certificate lifecycle (renewals, re-import, redeploy to instances), which is more overhead than Amazon-issued managed certificates.

Therefore, D best meets end-to-end encryption needs with the lowest ongoing operational burden by using AWS-managed certificate issuance and lifecycle management capabilities.

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.

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.

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

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.

A. EventBridge rule:Triggers an event whenever there is a change in CloudFront distribution, ensuring real-time monitoring.

B. ALB with WAF:Focuses on application-level security, not CloudFront logging.

C. Lambda + SNS:Provides notifications upon detection of changes in logging configuration.

D. GuardDuty:Monitors anomalies but does not specifically address CloudFront logging changes.

E. Private API + WAF:Irrelevant to CloudFront logging changes.

To secure data in transit, the company should use AWS Certificate Manager (ACM) to provide SSL/TLS certificates for the Application Load Balancer. ACM allows easy provisioning, management, and renewal of public and private certificates, ensuring secure communication between users and applications.

To secure data at rest, AWS Key Management Service (KMS) is used to manage encryption keys for Amazon EBS volumes. EBS integrates with AWS KMS, allowing for server-side encryption using KMS-managed keys (SSE-KMS), thus meeting the encryption at rest requirement.

Other options:

GuardDuty (A) is for threat detection, not encryption.

AWS Shield (B) protects against DDoS attacks, not encryption.

Secrets Manager (D) manages credentials, not general data encryption.

This solution follows the AWS Well-Architected Framework – Security Pillar.

???? References:

Encrypting EBS volumes with KMS

Using ACM with ALB

AWS Site-to-Site VPN is a cost-effective way to securely connect your on-premises data center with AWS resources. In this scenario:

Applications in private subnetsrequire access to the API hosted in the on-premises data center.

ASite-to-Site VPN connectionis a secure and cost-efficient option to route traffic between the VPC and on-premises resources.

Transit GatewayandPrivateLinkare not cost-effective for this use case.

NAT Gatewayonly provides internet access for private subnets, which is not suitable for reaching an on-premises resource.

AWS Documentation Reference:

AWS Site-to-Site VPN

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

AWS Lambda is event driven and “scales automatically with the number of requests,” charging per request and compute duration in milliseconds; you can schedule with Amazon EventBridge rules. Allocating 1 GB memory proportionally increases available CPU, which suits short CPU bursts. For a 10-second, once-per-hour job, Lambda eliminates instance idle time, providing the lowest cost and no servers to manage. Fargate tasks (A) bill per-second with a 1-minute minimum and require container packaging; for a 10-second job, costs are higher than Lambda. Options C and D keep EC2 management overhead and either maintain instances or add start/stop orchestration complexity; EC2 costs dominate because the instance sits idle for 59+ minutes each hour. Therefore, Lambda + EventBridge is the most cost-effective and operationally simple solution.

Amazon SQS provides durable, decoupled message storage for distributed systems. Using SQS as a job queue enables each EC2 instance to process a message independently. Scaling the Auto Scaling group based on the SQS queue length ensures parallelism and elasticity, aligning compute resources with workload volume.

To decouple distributed workloads and improve scalability and resiliency, Amazon SQS should be used as a reliable job queue. The compute nodes (workers) can poll the SQS queue for tasks, and EC2 Auto Scaling can dynamically scale instances based on the ApproximateNumberOfMessages metric.

From AWS Documentation:

“Amazon SQS enables you to decouple application components, allowing each part to scale independently. You can scale EC2 instances automatically based on the number of messages in the queue.”

(Source: Amazon SQS Developer Guide – Scaling Consumers with Auto Scaling)

Why B is correct:

Eliminates the single point of failure (the primary coordinator).

Enables event-driven scaling based on queue depth.

Provides durability and resiliency since messages are stored redundantly.

Fully managed and integrates seamlessly with Auto Scaling policies.

Why other options are incorrect:

A: Scheduled scaling does not respond to variable workloads.

C & D: Misuse of CloudTrail/EventBridge; not intended for workload coordination.

Amazon ECS on AWS Fargate: AWS Fargate is a serverless compute engine for containers that works with Amazon ECS. It allows you to run containers without managing servers or clusters.

Amazon EFS: Amazon Elastic File System (EFS) provides a simple, scalable, fully managed elastic NFS file system for use with AWS Cloud services and on-premises resources. It can be mounted to ECS tasks running on Fargate, allowing containers to access a shared file system with standard file system semantics, including OS-level permissions.

The design already uses one transit gateway (TGW) per Region and inter-Region TGW peering, which addresses the multi-Region AWS-side routing. The remaining requirement is to extend on-premises connectivity over Direct Connect so that on-premises networks can reach VPCs attached to the TGWs across all three Regions. The most operationally efficient and scalable approach is to use AWS Direct Connect Gateway (DXGW) with a transit virtual interface (transit VIF) and then associate the Regional transit gateways to that DXGW.

Option C is purpose-built for this: a transit VIF is specifically used to connect a Direct Connect connection to a Direct Connect gateway, and a DXGW can then be associated to multiple transit gateways (and can be used across Regions), enabling centralized connectivity from on-premises to TGW-connected VPCs. With TGW attachments and TGW route tables, you can propagate and control routes across many VPCs and accounts, which fits the “50 accounts, thousands of VPCs” scale. Inter-Region TGW peering then allows on-premises routes learned via the DXGW/TGW in one Region to reach workloads in the other Regions through the TGW peering relationships, subject to routing configuration.

Option A is too limited and not scalable because it ties Direct Connect to a virtual private gateway (VGW) associated with a single VPC, which does not meet the multi-VPC, multi-account hub-and-spoke requirement. Option B incorrectly suggests associating a DXGW with a VGW “in each VPC” (VGW is per VPC and would not scale well here, and it doesn’t integrate with the TGW hub design you’ve already built). Option D is not the intended pattern: Site-to-Site VPN and public VIF do not replace the DXGW + transit VIF architecture for large-scale TGW-based private routing.

A Network Load Balancer operates at Layer 4 (TCP/UDP/TLS) and is optimized for high performance and static IP use cases. While NLB target groups can perform health checks, they are typically oriented around basic reachability and do not provide the same application-layer (Layer 7) visibility as an Application Load Balancer (ALB). The problem statement says the NLB is “not detecting HTTP errors,” which indicates the health signal needs to be based on an HTTP endpoint that can reflect application correctness (for example, returning specific HTTP status codes).

Replacing the NLB with an ALB enables true HTTP/HTTPS health checks against a URL path, including interpretation of HTTP response codes. This is the cleanest managed approach to detect application-layer failure modes that still allow TCP connections but produce bad HTTP responses. Once the ALB detects targets as unhealthy, the target group health status can be used by an Auto Scaling group to take action. With appropriate health check configuration (and, commonly, using ELB health checks as a signal), Auto Scaling can replace unhealthy instances automatically, improving availability without custom scripts.

Option A is misleading: NLB does not provide the same HTTP-aware request routing and rich L7 features; even if an NLB health check is configured, it does not address the broader need for application-layer detection and remediation as directly as ALB. Option B violates the “no custom scripts” requirement. Option D reacts to UnhealthyHostCount, but if the NLB isn’t marking hosts unhealthy for HTTP error cases, the metric won’t reliably trigger replacement; it also still depends on the NLB’s limited visibility into HTTP failures.

Therefore, C best meets the requirement by shifting to ALB for application-layer health checks and using Auto Scaling to replace unhealthy instances automatically.

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.

DynamoDB Accelerator (DAX) is a fully managed, in-memory cache for DynamoDB that delivers up to a 10x performance improvement—even at millions of requests per second. DAX requires minimal changes to existing applications and offloads the read workload from DynamoDB during report generation.

Reference Extract:

"DAX provides in-memory acceleration for DynamoDB tables, reducing response times from milliseconds to microseconds with minimal application changes."

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

AWS Service Catalogallows organizations to centrally manage commonly deployed IT services and offers self-service deployment capabilities to customers. By creatingService Catalog products, the consulting company can package their solutions and tools for easy reuse by customers while maintaining central control over configuration and access. This provides a standardized and automated solution with the least operational overhead for managing and deploying solutions across different customers.

Option A (CloudFormation): CloudFormation templates are useful but don't provide the same level of management and user-friendly self-service capabilities as Service Catalog.

Option C (Systems Manager): Systems Manager is more focused on managing infrastructure and doesn't offer the same self-service capabilities.

Option D (AWS Config): AWS Config is used for tracking resource configurations, not for deploying solutions.

AWS References:

AWS Service Catalog

Aurora I/O-Optimized: This storage configuration is designed to provide consistent high performance for Aurora databases. It automatically scales IOPS as the workload increases, without needing to provision IOPS separately.

Cost-Effectiveness: With Aurora I/O-Optimized, you only pay for the storage and I/O you use, making it a cost-effective solution for applications with varying and unpredictable I/O demands.

Implementation:

During the creation of the Aurora PostgreSQL Serverless v2 cluster, select the I/O-Optimized storage configuration.

The storage system will automatically handle scaling and performance optimization based on the application load.

Operational Efficiency: This configuration reduces the need for manual tuning and ensures optimal performance without additional administrative overhead.

Amazon SQS is a fully managed message queuing service that reliably decouples and scales microservices, distributed systems, and serverless applications. By using SQS, microservices can communicate asynchronously, handle bursts of traffic, and avoid data loss by buffering messages until they are processed. Deploying the services on ECS with AWS Fargate further reduces operational overhead by removing the need to manage servers, allowing independent scaling of each microservice.

Reference Extract:

"Amazon SQS decouples application components and enables message durability and scaling. AWS Fargate removes the need to manage infrastructure, supporting independent scaling and minimal operational overhead."

Source: AWS Certified Solutions Architect – Official Study Guide, Microservices and Messaging section.

Predictive scaling in EC2 Auto Scaling uses machine learning to analyze historical load and forecast future capacity needs, then pre-scales capacity before the demand occurs. It is specifically designed for recurring, cyclical workloads such as weekly batch jobs.

In this scenario:

The workload pattern is known and recurring (weekly scripted jobs).

The company explicitly does not want to manually analyze trends.

They need capacity to be ready 30 minutes before jobs start.

Predictive scaling lets you:

Set the metric (CPU utilization) and target (60%).

Configure the policy to pre-launch instances 30 minutes in advance, satisfying the requirement automatically with minimal operational overhead.

Dynamic scaling (Option A) reacts after CPU increases, not before.

Scheduled scaling (Option B) requires manual analysis and ongoing adjustment of capacity values.

EventBridge + Lambda (Option D) introduces unnecessary custom logic and still reacts after CPU reaches 60%, not 30 minutes before.

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.

DynamoDB Global Tablesprovide a fully managed, multi-region, and multi-master database solution that allows you to deploy DynamoDB tables in multiple AWS Regions. This ensures high availability and resiliency across different geographical locations, providing a seamlessgaming experience for users. Usingprovisioned capacity modewithauto-scalingensures cost-efficiency by scaling up or down based on actual demand.

Option A: While on-demand capacity mode is flexible, provisioned capacity with auto-scaling is more cost-effective for predictable workloads.

Option B (DAX): DAX improves read performance, but it doesn't provide the multi-region replication needed for high availability and resiliency.

Option C: DynamoDB Streams with manual cross-region replication adds more complexity and operational overhead compared to Global Tables.

AWS References:

DynamoDB Global Tables

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.

Amazon S3 Glacier Flexible Retrieval is a low-cost archival storage class that supports retrieval of data within minutes (expedited access ~1–5 minutes), making it ideal for audit scenarios where occasional, quick access to archived data is required. In contrast, Glacier Deep Archive takes hours to retrieve.

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

Amazon FSx for Lustre is the ideal solution for high-performance computing (HPC) workloads that require parallel access to a shared file system with low latency. FSx for Lustre is designed specifically to meet the needs of such workloads, offering sub-millisecond latencies, which makes it well-suited for the 1 ms latency requirement mentioned in the question.

Here is why FSx for Lustre is the best fit:

Parallel File System: FSx for Lustre is a parallel file system that can scale across hundreds of Amazon EC2 instances, providing high throughput and low-latency access to data. It is optimized for processing large datasets in parallel, which is essential for HPC workloads.

Low Latency: FSx for Lustre is capable of providing access latencies well within 1 ms, making it ideal for performance-sensitive workloads like HPC.

Seamless Integration with Amazon S3: FSx for Lustre can be linked to an Amazon S3 bucket. This integration allows data to be imported from S3 into FSx for Lustre before the workload begins and exported back to S3 after processing. This feature is crucial for manual postprocessing because it enables engineers to access the dataset in S3 after processing.

Performance: FSx for Lustre is built for workloads that require high performance, such as machine learning, analytics, media processing, and financial simulations, which are typical for HPC environments.

In contrast:

Amazon EFS (Option A): While EFS provides shared file storage and scales across multiple EC2 instances, it does not offer the same level of performance or sub-millisecond latencies as FSx for Lustre. EFS is more suited for general-purpose workloads, not high-performance computing.

Mounting S3 as a file system (Option B and D): S3 is object storage, not a file system designed for low-latency access and parallel processing. Mounting S3 buckets directly or using AWS Resource Access Manager to share the bucket would not meet the low-latency (1 ms) or performance requirements needed for HPC workloads.

Therefore, Amazon FSx for Lustre (Option C) is the most appropriate and verified solution for this scenario.

AWS References:

Amazon FSx for Lustre

Best Practices for High Performance Computing (HPC)

Amazon FSx and Amazon S3 Integration

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.

Amazon S3 with Amazon CloudFront:

Amazon S3 provides highly scalable and durable storage for petabytes of data.

Amazon CloudFront, as a content delivery network (CDN), caches frequently accessed data at edge locations to reduce latency. This combination is ideal for storing and accessing engineering drawings.

Incorrect Options Analysis:

Option B: Amazon S3 Glacier Deep Archive is for long-term archival storage, not frequent access.

Option C: Amazon EBS is unsuitable for large-scale, multi-user data access and does not support caching directly.

Option D: AWS Storage Gateway is for hybrid cloud storage, which is unnecessary for a fully cloud-based architecture.

AWS Security Hub provides a centralized view of security findings across AWS accounts and services. It integrates natively with AWS Config conformance packs, which evaluate compliance against industry standards such as CIS and PCI-DSS.

From AWS Documentation:

“AWS Security Hub aggregates, organizes, and prioritizes security alerts and compliance status across AWS accounts. Use AWS Config conformance packs to assess compliance with security frameworks.”

(Source: AWS Security Hub User Guide – Managing Findings and Compliance)

Why C is correct:

Security Hub provides a centralized dashboard for compliance visibility.

Conformance packs in AWS Config automate compliance checks across accounts.

Fully managed, minimal maintenance, and integrates natively with AWS services.

Why others are incorrect:

A: Conformance packs are not a feature of Amazon Inspector.

B: Third-party tools on EC2 require management and add operational overhead.

D: Systems Manager is not designed for compliance aggregation.

Explanation (AWS Docs):

To allow private subnets to access the internet, deploy NAT gateways in a public subnet in each AZ for high availability. NAT instances are less scalable and less fault-tolerant.

“To create a highly available architecture, create a NAT gateway in each Availability Zone and configure your routing to use it.”

— NAT Gateway Overview

AWS STS issues temporary credentials with automatically expiring permissions based on IAM roles. This eliminates the need to manually manage or deactivate IAM users.

“You can use AWS STS to grant temporary security credentials that automatically expire after a specified duration.”

— Temporary Security Credentials

This is the least operational overhead and follows AWS best practices for short-term access.

Amazon RDS for Oracle is a managed database service, which significantly reduces operational overhead compared to running Oracle on EC2 or on-premises. AWS Secrets Manager natively integrates with RDS and supports automatic, scheduled password rotation with minimal setup. You can configure the rotation schedule (including yearly), and Secrets Manager will handle the secure password storage and rotation workflow for you.

AWS Documentation Extract:

"AWS Secrets Manager helps you protect access to your applications, services, and IT resources without the upfront investment and on-going maintenance costs of operating your own infrastructure. You can configure automatic rotation for supported databases such as Amazon RDS for Oracle."

(Source: AWS Secrets Manager documentation)

A, C, D: These solutions require custom scripting, Lambda, and alarms, leading to more operational overhead.

Amazon Kinesis Data Firehose (now known as Amazon Data Firehose) supports near-real-time streaming, with built-in support to:

Invoke AWS Lambda functions for transformation.

Store data directly into Amazon S3 in desired formats like Apache Parquet.

“You can use Data Firehose to transform the data before delivering it, by invoking a Lambda function. You can convert to formats such as JSON or Apache Parquet before storing it into S3.”

— Amazon Data Firehose Developer Guide

Why not the others?

B: Kinesis Data Streams requires more operational overhead than Firehose.

C: DataSync is for file movement—not stream processing.

D: SQS isn’t designed for streaming and transformation pipelines.

AWS Site-to-Site VPN: This provides a secure and encrypted connection between an on-premises environment and AWS. It is a cost-effective solution suitable for low bandwidth and small traffic needs.

Quick Setup:

Site-to-Site VPN can be quickly set up by configuring a virtual private gateway on the AWS side and a customer gateway on the on-premises side.

It uses standard IPsec protocol to establish the VPN tunnel.

Cost-Effectiveness: Compared to AWS Direct Connect, which requires dedicated physical connections and higher setup costs, a Site-to-Site VPN is less expensive and easier to implement for smaller traffic requirements.

The company’s requirements are:

Store gigabytes of rarely accessed files daily.

Files must be available within minutes during the first year.

Retain files for 7 years cost-effectively.

The S3 Glacier Instant Retrieval storage class provides low-cost, long-term storage for data accessed occasionally, with millisecond retrieval time. This fits the requirement for availability within minutes during the first year. After one year, transitioning files to S3 Glacier Deep Archive (the lowest cost S3 storage class) with longer retrieval times is cost-effective for data retention over 7 years.

Option B uses S3 Standard and Glacier Flexible Retrieval, which is higher cost during the first year and slower retrieval times. Option C is less cost-efficient because EBS volumes are expensive for rarely accessed data and snapshots incur additional costs. Option D uses EFS, which is designed for low-latency file storage but is more expensive than S3 Glacier classes for long-term archival.

Amazon Data Lifecycle Manager (DLM) automates the creation, retention, and deletion of EBSsnapshots. This allows organizations to define policies that ensure snapshots are only kept as long as needed, reducing costs automatically and minimizing manual effort. AWS recommends using DLM for optimizing storage and managing backup lifecycle with minimal overhead.

The best solution is to useAmazon SQSto receive updates from the mobile app and process them with anAWS Lambdafunction. The Lambda function can rewrite the message body as necessary for each shipper and then publish the updates to the appropriateSNS topicfor distribution. Thissetup ensures that each shipper receives only the relevant data and minimizes operational overhead by using managed services.

Option A (SNS filter policy): SNS does not have the capability to rewrite message bodies before forwarding.

Option C (Second SNS topic): Using an additional SNS topic adds unnecessary complexity without solving the message rewriting requirement.

Option D (EventBridge Pipes): EventBridge Pipes is more complex than necessary for this use case, and Lambda can handle the logic more efficiently.

AWS References:

Amazon SQS

Amazon SNS with Lambda

The requirement is to monitor network metrics such as total packet loss and round-trip time (RTT) between on-premises and AWS over Site-to-Site VPN with minimal operational overhead. AWS CloudWatch Network Monitor (formerly known as VPC Network Manager) provides a managed solution to monitor connectivity, including packet loss and latency, between AWS and on-premises networks. This solution does not require managing any additional infrastructure like EC2 instances or Lambda functions and thus reduces operational overhead significantly.

CloudWatch Network Monitor leverages AWS-managed probes and integrates natively with CloudWatch dashboards and alarms, enabling automated, centralized monitoring of network health. This aligns with the AWS Well-Architected Framework’s operational excellence pillar by minimizing manual intervention and enabling proactive detection of network issues.

Option B, C, and D involve creating custom probes with EC2, Lambda, or Batch jobs, which increases complexity, cost, and maintenance effort. They also require scheduling, script management, and additional monitoring infrastructure.

This question centers on improving scalability and global access performance.

Auto Scaling groups enable EC2 instances to scale dynamically in response to demand, ensuring availability during peak hours without manual intervention. Amazon RDS read replicas offload read traffic, improving read throughput and reducing latency on the primary database instance. Deploying Amazon CloudFront with S3 as origin accelerates delivery of static transaction documents globally by caching content at edge locations, reducing latency for users worldwide.

Option B focuses on vertical scaling (larger instances) and caching with ElastiCache, but it does not address global content delivery optimally. AWS Global Accelerator accelerates network traffic but is better suited for accelerating TCP and UDP traffic; CloudFront is generally preferred for HTTP content delivery.

Option C migrates workloads to Lambda and Aurora global databases, which is an advanced and potentially costly redesign that may not be necessary. Option D suggests moving to ECS and multi-AZ RDS but does not address global content delivery efficiently.

Therefore, option A uses proven scalability and caching best practices aligned with AWS Well-Architected Framework pillars for performance and operational excellence.

Using API Gateway and Lambda enables serverless handling of form submissions with minimal cost and infrastructure. When coupled with Amazon SNS, it allows instant email notifications without running servers, making it ideal for low-traffic workloads.

S3 Object Lock: Enables Write Once Read Many (WORM) protection for data, preventing objects from being deleted or modified for a set retention period.

S3 Versioning: Helps maintain object versions and ensures a recovery path for accidental overwrites.

CloudFront Distribution: Ensures secure and efficient public access by serving content through an edge-optimized delivery network while protecting S3 data with OAC.

Bucket Policy for OAC: Restricts public access to only the CloudFront origin, ensuring maximum security.

Amazon S3 Object Lock Documentation

To ensure high availability and scalability, the web application should run in anAuto Scaling groupacross two Availability Zones behind anApplication Load Balancer (ALB). The database should be migrated toAmazon RDSwithMulti-AZ deployment, which ensures fault tolerance and automatic failover in case of an AZ failure. This setup minimizes administrative overhead while meeting the company's requirements for high availability and scalability.

Option A: Read replicas are typically used for scaling read operations, and Multi-AZ provides better availability for a transactional database.

Option B: Replicating across AWS Regions adds unnecessary complexity for a single web application.

Option D: EC2 instances across three Availability Zones add unnecessary complexity for this scenario.

AWS References:

Auto Scaling Groups

Amazon RDS Multi-AZ

Amazon Elastic File System (EFS) is the ideal solution for migrating legacy applications that require NFS (Network File System) communication. EFS provides fully managed, scalable NFS storage in the cloud, and it supports the standard NFS protocols, allowing the legacy application to continue using NFS without modification after migration to AWS.

Key AWS features:

NFS Support: EFS natively supports the NFSv4 protocol, which makes it the best solution for workloads that rely on NFS communication.

Scalability and Availability: EFS automatically scales as application demands grow, making it a highly available and reliable storage solution.

AWS Documentation: According to AWS’s best practices for file storage, EFS is recommended for any workloads requiring NFS support in a cloud environment​​.

For SQS-backed worker architectures, AWS recommends scaling consumers based on queue metrics (e.g., ApproximateNumberOfMessagesVisible, AgeOfOldestMessage). EC2 Auto Scaling can “scale out based on Amazon CloudWatch alarms” tied to SQS backlog, increasing worker capacity to reduce latency as demand grows. DAX (A) accelerates DynamoDB reads, not message processing. API Gateway (B) and CloudFront (C) optimize request ingress and content delivery, not the asynchronous email-sending application. The bottleneck is consumer throughput; scaling workers with an SQS-driven policy restores timely processing without downtime and follows Well-Architected patterns for decoupled, elastic systems.

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

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.

To run RDS instances only during business hours with the least operational overhead, you can useAmazon EventBridgeto schedule events that invokeAWS Lambda functions. The Lambda functions can be configured to start and stop the RDS instances based on the specified schedule (business hours). EventBridge rules allow you to define recurring events easily, and Lambda functions provide a serverless way to manage RDS instance start and stop operations, reducing administrative overhead.

Option A: While CloudWatch alarms could be used, they are more suited for monitoring, and using Lambda with EventBridge is simpler.

Option B (Trusted Advisor): Trusted Advisor is not ideal for scheduling tasks.

Option C (Systems Manager): Systems Manager could also work, but EventBridge and Lambda offer a more streamlined and lower-overhead solution.

AWS References:

Amazon EventBridge Scheduler

AWS Lambda

Protecting an application from layer 7 (application layer) DDoS attacks is best achieved by using AWS WAF (Web Application Firewall), which provides customizable protection against common web exploits including DDoS attacks at the application layer. AWS WAF supports managed rule groups maintained by AWS, which offer robust, tested protections against OWASP top 10 vulnerabilities and common attack patterns without requiring extensive manual rule creation.

While AWS Shield Standard provides basic network-layer DDoS protection automatically at no additional charge, it does not offer application-layer filtering capabilities. Therefore, option A alone is insufficient.

Option B, involving only custom rules, requires significant operational overhead and expertise, whereas AWS managed rules offer a turnkey solution with ongoing updates from AWS security teams.

Option D, using CloudFront in front of the ALB, can provide additional protection benefits such as caching and geographic restrictions, but the question specifically asks for protecting against layer 7 DDoS on the ALB directly. CloudFront plus WAF is a valid enhanced solution, but the direct and recommended answer in AWS official documents is to use AWS WAF managed rules directly with ALB for application-level protection.

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.

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

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

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

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

Amazon S3 Glacier Flexible Retrieval is designed for long-lived, infrequently accessed data where retrieval times of minutes to hours are acceptable. It offers very low storage cost per GB while still supporting faster retrieval than archival tiers that can take many hours or days.

The requirement states that data is rarely accessed and must be retrievable within 12 hours. Glacier Flexible Retrieval meets this retrieval-time requirement and is more cost-effective per GB than Standard and Infrequent Access storage classes for long-term, rarely accessed data.

S3 Standard, S3 Standard-IA, and S3 One Zone-IA are optimized for more frequent or lower-latency access and have higher storage cost per GB compared to Glacier Flexible Retrieval.

For an application requiring TCP communication and high availability:

Network Load Balancer (NLB)is the best choice for load balancing TCP traffic because it is designed for handling high-throughput, low-latency connections.

Auto Scaling groupensures that the application can automatically scale based on demand, adding or removing EC2 instances as needed, which is crucial for handling user growth.

Option C (Application Load Balancer): ALB is primarily for HTTP/HTTPS traffic, not ideal for TCP.

Option D (Manual scaling): Manually adding instances does not provide the automation or scalability required.

Option E (Gateway Load Balancer): GLB is used for third-party virtual appliances, not for direct application load balancing.

AWS References:

Network Load Balancer

Auto Scaling Group

AWS Glue provides a serverless ETL solution requiring minimal development. Glue supports conversion to Parquet with managed jobs and integrates with S3 for output.

AWS Documentation References:

AWS Glue Overview

CloudFront Signed URLs: These URLs allow you to provide limited access to content that is being served through an Amazon CloudFront distribution. Signed URLs can be generated to grant time-limited access to premium customers.

Content Restriction:

By using CloudFront signed URLs, you can control access to your media streams and file content stored in S3.

These URLs can be customized with an expiration time, ensuring that access is only available for a specific period, which is useful for scenarios like movie rentals or music downloads.

Security and Flexibility:

Signed URLs ensure that only authenticated users (premium customers) can access the restricted content.

This approach integrates seamlessly with CloudFront and S3, providing an efficient way to manage access controls without additional overhead.

Operational Efficiency: Using CloudFront signed URLs leverages AWS managed services to handle the complexity of access control, reducing the need for custom implementation and maintenance.

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 Control Tower: Provides a managed service to set up and govern a secure, multi-account AWS environment based on AWS best practices. It automates the setup of AWS Organizations and applies security controls (guardrails).

Networking Account:

Create a centralized networking account that includes a VPC with both private and public subnets.

This centralized VPC will manage and control the networking resources.

AWS Resource Access Manager (AWS RAM):

Use AWS RAM to share the subnets from the networking account with the other workload accounts.

This allows different workload accounts to utilize the shared networking resources without the need to manage their own VPCs.

Operational Efficiency: Using AWS Control Tower simplifies the setup and governance of multiple AWS accounts, while AWS RAM facilitates centralized management of networking resources, reducing operational overhead and ensuring consistent security and compliance.

Amazon Route 53 supports failover routing policies, which use health checks to route DNS queries to a secondary Region only if the primary endpoint fails. This design ensures only one Region is active for traffic at any given time. This is the recommended architecture for active-passive, multi-Region DR strategies.

AWS Documentation Extract:

“Failover routing lets you route traffic to a primary resource, such as a web server in one Region, and a secondary resource in another Region. If the primary fails, Route 53 can route traffic to the secondary resource automatically.”

(Source: Amazon Route 53 documentation, Routing Policy Types)

A, D: These options do not configure DNS failover for external users.

C: Geolocation routing is for regional distribution, not DR failover.

Provisioned IOPS SSD (io1 or io2) is designed for I/O-intensive workloads that require low latency and consistent throughput, which is critical for transactional and production databases. It provides predictable performance, unlike General Purpose SSD, which is burst-based.

AWS Fargate with Spot capacity is the most cost-effective and serverless container option for short-duration jobs that are flexible on start time. Since the job is not latency-critical and runs nightly, it is a good candidate for Fargate Spot, which can offer up to 70% cost savings over On-Demand pricing.

The job runs for 1 hour, which exceeds the AWS Lambda maximum execution time (15 minutes). Therefore, Lambda is not suitable. EC2-based solutions involve higher operational overhead and cost, making Fargate Spot the best low-cost, low-maintenance solution.

Amazon DynamoDB is a serverless, NoSQL database that is fully managed, highly available, and scales automatically. It is ideal for data without a fixed schema and for use cases where fields can vary by user. DynamoDB Streams enables the capture of changes to table items in real time, which is ideal for triggering additional processing or workflows on data modifications.

Reference Extract from AWS Documentation / Study Guide:

"DynamoDB provides a scalable, highly available NoSQL database service for applications requiring flexible schema. DynamoDB Streams captures table activity for processing changes in real time."

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

HPC workloads require high-throughput, low-latency networking, especially for tightly-coupled applications like weather modeling, genomics, or real-time rendering.

A cluster placement group places instances in the same Availability Zone and on physically connected hardware, reducing network latency and increasing throughput.

Elastic Fabric Adapter (EFA) is a network device for EC2 instances that enables low-latency, high-throughput networking using OS-bypass technology, ideal for tightly-coupled HPC applications.

Each instance can support single-flow 10 Gbps bandwidth using EFA, and collectively, the cluster can achieve up to 100 Gbps aggregate throughput when properly configured.

This solution supports the Performance Efficiency and Resilience design principles and is a standard AWS-recommended pattern for HPC.

???? References:

EC2 Placement Groups

Elastic Fabric Adapter Overview

Best Practices for HPC on AWS

To securely integrate Amazon S3 with an application that uses Amazon Cognito for user authentication, the following two steps are essential:

Step 1: Create an Amazon Cognito Identity Pool (Option A)

Amazon Cognito Identity Poolsallow users to obtain temporary AWS credentials to access AWS resources, such as Amazon S3, after successfully authenticating with the Cognito user pool. The identity pool bridges the gap between user authentication and AWS service access by generating temporary credentials using AWS Identity and Access Management (IAM).

Once a user logs in using theCognito User Pool, the identity pool providesIAM roles with specific permissionsthat the application can use to access S3 securely. This ensures that each user has appropriate access controls while accessing the S3 bucket.

This is a secure way to ensure that users only have temporary and least-privilege access to the S3 bucket for their documents.

Step 2: Create an Amazon S3 VPC Endpoint (Option C)

By creating anAmazon S3 VPC endpoint, the company ensures that communication between the application (which is hosted in a private subnet) and the S3 bucket occurs over theAWS private network, without the need to traverse the internet. This enhances security and prevents exposure of data to public networks.

TheVPC endpointallows the application to access the S3 bucket privately and securely within the VPC. It also ensures that traffic stays within the AWS network, reducing attack surface and improving overall security.

Why the Other Options Are Incorrect:

Option B: This is incorrect becauseAmazon Cognito User Poolsare used for user authentication, not for generating S3 access tokens. To provide S3 access, you need to useAmazon Cognito Identity Pools, which offer AWS credentials.

Option D: ANAT gatewayis unnecessary in this scenario. Using aVPC endpointfor S3 access provides a more secure and cost-effective solution by keeping traffic within AWS.

Option E: Attaching a policy to restrict access based on IP addresses is not scalable or efficient. It would require managing users’ dynamic IP addresses, which is not an effective security measure for this use case.

AWS References:

Amazon Cognito Identity Pools

Amazon VPC Endpoints for S3