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

The production workload is steady and long-running, so a commitment-based discount is appropriate there. Compute Savings Plans are a flexible way to reduce cost for consistent production compute usage. The nonproduction environments run only during weekday business hours and can be shut down when not in use, so using On-Demand Instances and turning them off outside working hours is more cost-effective than reserving or dedicating capacity for them. Dedicated Hosts would be unnecessarily expensive, and reserving nonproduction capacity would waste money on idle time. Therefore, combining Compute Savings Plans for production with shut-down On-Demand nonproduction environments is the most cost-efficient design.

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

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

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

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

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

— AWS Direct Connect Documentation

— VPC Peering Guide

Why not others:

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

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

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

Option B is the best answer because AWS Budgets can take automated actions, and forecast-based thresholds let the company intervenebeforeactual spending fully lands. AWS documentation explains that AWS Budgets actions can target EC2 instances, and forecast-based budget alerts are specifically intended to warn when projected spend is expected to exceed the threshold during the period. That makes forecasted costs more proactive than waiting until actual spend reaches the full budgeted amount. Option A works, but it adds extra operational overhead by introducing SNS and Lambda when AWS Budgets actions can already automate the response directly. Option C is unrelated because a scheduled rule does not respond to budget state. Therefore, forecast-based AWS Budgets actions that automatically stop the EC2 instances is the most cost-effective and direct design. (AWS Documentation)

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Amazon S3 Express One Zone provides single-digit millisecond latency and high throughput, making it ideal for ML workloads that require multiple compute nodes and fast access. It is also more cost-effective than traditional file or block storage for temporary, high-speed needs.

Amazon QLDB is the most cost-effective and suitable service for maintainingimmutable, cryptographically verifiable logsof data changes. QLDB provides a fully managed ledgerdatabase with a built-in cryptographic hash chain, making it ideal for recording changes to accounting records, ensuring data integrity and security.

QLDB reduces operational overhead by offering fully managed services, so there’s no need for server management, and it’s built specifically to ensure immutability and verifiability, making it the best fit for the given requirements.

Option A (Redshift): Redshift is designed for analytics and not for immutable, cryptographically verifiable logs.

Option B (Neptune): Neptune is a graph database, which is not suitable for this use case.

Option C (Timestream): Timestream is a time series database optimized for time-stamped data, but it does not provide immutable or cryptographically verifiable logs.

AWS References:

Amazon QLDB

How QLDB Works

This workload is a strong candidate forAWS Batch with EC2 Spot Instancesbecause the jobs can tolerate interruptions and resume after restart. AWS documents that Spot Instances are a cost-saving option for interruption-tolerant workloads, and AWS Batch is built to manage batch jobs efficiently across EC2 capacity. AWS Batch guidance also notes that Spot is well suited when jobs can be retried or resumed, which matches the scenario. On-Demand Capacity Reservations do not optimize cost, and Savings Plans still cost more than Spot for an interruption-tolerant batch pattern. Therefore, AWS Batch with Spot gives the best balance of automation and lower compute cost.

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Edge-optimized API Gateway endpoints utilize the Amazon CloudFront global network to decrease latency for clients globally. This setup ensures that the request is routed to the closest edge location, significantly reducing response time and improving performance for worldwide users.

AWS WAF (Web Application Firewall) is designed to protect public-facing web applications from common web exploits and allows for deep inspection of HTTP and HTTPS requests. By enabling logging on AWS WAF, you can gain insights into traffic flow, request sources, and blocked requests, which improves both security visibility and posture. Integrating AWS WAF logging with Amazon Kinesis Data Firehose allows automatic, near-real-time delivery of log data to Amazon S3 for analysis, reporting, or integration with analytics tools. This solution not only secures the website but also enables comprehensive traffic analysis, satisfying both requirements efficiently.

Reference Extract from AWS Documentation / Study Guide:

" AWS WAF provides detailed logs of web requests, which can be delivered to Amazon S3 via Amazon Kinesis Data Firehose. This logging enables analysis of web traffic and sources, supporting both security and operational monitoring. "

Source: AWS Certified Solutions Architect – Official Study Guide, Security and Compliance section; AWS WAF Developer Guide (Logging and Monitoring).

A read replica is the best answer because the new application needs to read frequently changing data while minimizing load on the production writer. Amazon RDS read replicas are designed to offload read traffic from the primary DB instance, which improves overall performance for the main workload. ElastiCache is not the best fit because the application rarely repeats the same query, so a cache would not provide strong benefit. An ALB is unrelated to database querying, and snapshots are not appropriate for querying near-current data. Since the requirement is fresh read access with minimal impact on the primary database, using a read replica is the correct architectural choice.

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Detailed Explanation:

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

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

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

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

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

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

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

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

AWS Documentation References:

Amazon S3 Event Notifications

AWS Lambda Overview

To securely publish messages to an encrypted Amazon SNS topic, the following steps are required:

A. Resource policy for SNS topic:Ensures that the Lambda function is explicitly allowed to publish messages to the topic.

C. Resource policy for KMS key:Provides the necessary permissions to use the customer-managed key for encryption.

F. Lambda execution role:Grants the Lambda function the necessary IAM permissions to use the encryption key.

Other options:

Bis invalid because using SSE-KMS does not eliminate the need for resource policies.

Doverlaps with A, but specifying the ARN in the topic policy is covered by creating the resource policy.

Eis unrelated as API Gateway is not required for this setup.

AWS Documentation Reference:

Amazon SNS and KMS Permissions

Amazon ECS on AWS Fargate with Amazon EFS is the best match because it combines managed container orchestration with shared persistent storage. AWS documentation explains that Amazon EFS volumes can be used with Amazon ECS so tasks can access the same persistent file system regardless of where they run. AWS also notes that EFS volumes are useful for horizontally scaled containerized applications that need shared storage, low latency, and high throughput. Lambda is a poor fit here because Lambda invocations have a maximum timeout of 15 minutes, while the question states processing can take up to 1 hour. Instance store volumes on ECS EC2 are local to the host and do not provide the centralized persistent repository the workload needs. Fargate plus EFS best satisfies performance, duration, and operational efficiency.

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

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

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

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

Amazon S3 File Gateway provides a local NFS mount point, which can be used with minimal changes by the legacy application. Files are transparently uploaded to Amazon S3, allowing the web application to access them directly from S3. This is the most cost-effective and operationally simple way to bridge legacy on-premises NFS output with S3, requiring no changes to the batch process.

AWS Documentation Extract:

“With S3 File Gateway, you can provide applications a local file interface to Amazon S3. S3 File Gateway presents a file-based interface (NFS or SMB), allowing you to use S3 as your scalable, durable storage while making files available to legacy applications.”

(Source: AWS Storage Gateway documentation)

A: Outposts is far more costly and complex than needed.

B: Volume Gateway presents iSCSI block storage, not NFS.

C: Requires re-coding the legacy app to use S3 APIs, not NFS.

Amazon DocumentDB global clusters support managed cross-region failover, allowing you to promote a secondary region to become the new primary with minimal downtime. This ensures business continuity during maintenance or regional disruptions.

Reference Extract:

" Amazon DocumentDB global clusters support managed cross-Region failover, allowing you to recover quickly from regional disruptions with minimal downtime. "

Source: AWS Certified Solutions Architect – Official Study Guide, DocumentDB and Resiliency section.

Amazon S3 Intelligent-Tiering is the most cost-effective solution for this scenario, providing both high availability and durability while adjusting automatically to changing access patterns. It moves data across two access tiers: one optimized for frequent access and another for infrequent access, based on usage patterns. This tiering ensures that the company avoids paying for unused storage while also keeping frequently accessed data in a more accessible tier.

Key AWS references and benefits ofS3 Intelligent-Tiering:

High Durability and Availability: Amazon S3 offers 99.999999999% durability and 99.9% availability for objects stored, ensuring data is always protected.

Automatic Tiering: Data is automatically moved between tiers based on access patterns, making it ideal for workloads with unpredictable or variable access patterns.

No Retrieval Fees: Unlike S3 One Zone-IA or Glacier, there are no retrieval fees, making this more cost-effective in scenarios where access patterns vary over time.

AWS Documentation: According to the AWS Well-Architected Framework under theCost Optimization Pillar, S3 Intelligent-Tiering is recommended for storage when access patterns change over time, as it minimizes costs while maintaining availability​.

The requirement combines two key goals: reduce post-migration database administration/maintenance cost and minimize application rewrites for an existing Microsoft SQL Server application that relies heavily on T-SQL and stored procedures. Amazon Aurora PostgreSQL-Compatible with Babelfish is designed for this exact migration pattern: it helps applications written for SQL Server to run with reduced code changes by providing compatibility for commonly used SQL Server semantics, including T-SQL constructs, procedural logic, and SQL Server-style connectivity patterns (depending on feature usage). Aurora itself is a managed database service that reduces operational overhead compared to self-managed databases by offloading tasks such as provisioning, patching (within service capabilities), backups, and high availability patterns.

Option C (RDS for SQL Server) would indeed minimize rewrites because it keeps the engine the same, but it typically does not optimize operating costs as effectively as migrating off commercial SQL Server licensing/edition costs; it also keeps you on the same engine family, which often carries higher license implications and may not meet the “minimize operating costs” intent as strongly as moving to Aurora PostgreSQL with Babelfish. Option B is not suitable because Redshift Spectrum is for analytics over data in S3, not for running an OLTP ecommerce database with stored procedures. Option D is also a mismatch: EMR is for big data processing frameworks, not a relational OLTP database replacement for SQL Server.

Therefore, A best balances lower ongoing operational cost with reduced refactoring effort by using Aurora’s managed capabilities while leveraging Babelfish to ease SQL Server-to-PostgreSQL migration friction.

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

Amazon SQS FIFO queues support deduplication and ordering. AWS documents thatMessageDeduplicationIdis used with FIFO queues to prevent duplicate delivery within a5-minute deduplication window, which matches this requirement exactly. Standard queues do not provide this deduplication guarantee, and SNS filter policies are not a deduplication mechanism for this use case. Because the company wants the least development effort, using API Gateway to place messages directly on an SQS FIFO queue with a deduplication token is the cleanest approach.

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