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

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.

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

For this scenario, best practice is to:

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

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

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

This approach:

Prevents OS vulnerabilities from being introduced at deployment time.

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

Minimizes manual effort and reduces drift between instances.

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

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

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

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

Gateway Endpoint for Amazon S3: A VPC endpoint for Amazon S3 allows you to privately connect your VPC to Amazon S3 without requiring an internet gateway, NAT device, VPN connection, or AWS Direct Connect connection.

Provisioning the Endpoint:

Navigate to the VPC Dashboard.

Select "Endpoints" and create a new endpoint.

Choose the service name for S3 (com.amazonaws.region.s3).

Select the appropriate VPC and subnets.

Adjust the route tables of the subnets to include the new endpoint.

Update Route Tables: Modify the route tables of the subnets to direct traffic destined for S3 to the newly created endpoint. This ensures that traffic to S3 does not go through the NAT instance, avoiding the saturated network and eliminating timeouts.

Operational Efficiency: This solution minimizes operational overhead by removing dependency on the NAT instance and avoiding internet traffic, leading to more stable and secure S3 interactions.

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.

Same scenario as above—cost-effective cold start reduction for Java Lambdas is best achieved by using Lambda SnapStart with the correct code structure. Unique IDs and similar non-deterministic logic should be in the handler or in a pre-snapshot hook. SnapStart is supported only for published versions. This combination offers cold start performance at a lower cost than provisioned concurrency.

AWS Documentation Extract:

"When using Lambda SnapStart for Java, ensure non-deterministic initialization code, such as unique ID generators, is executed inside the handler or in a pre-snapshot hook. SnapStart is supported only on published versions."

(Source: AWS Lambda documentation, SnapStart for Java)

Creating a manual copy of the automated snapshot is the most operationally efficient option because it directly meets the requirement—retain a specific snapshot beyond the automated retention window—with the least added process and tooling. In Amazon RDS, automated backups and their snapshots are retained only for the configured backup retention period (up to the service maximum). When that retention period is exceeded, older automated snapshots are removed automatically. However, manual snapshots are retained until you explicitly delete them, so converting (copying) an automated snapshot to a manual snapshot is the standard operational approach to keep a point-in-time backup for long-term retention.

Option C is incorrect because you cannot extend automated snapshot retention beyond the maximum supported retention; also, setting “45 days” may still be within or beyond the service limits depending on the engine and configuration, and it doesn’t guarantee indefinite retention. Option B (export to S3) is not the most operationally efficient for the stated goal: exporting is a different workflow (often used for analytics, archiving in open formats, or cross-tool usage) and introduces extra steps, format considerations, and ongoing management in S3. Option D is also heavier operationally: native SQL Server backups require managing backup jobs, storage layout, restores, and permissions, and it shifts responsibility to the customer for operational correctness.

Therefore, A is the simplest and most AWS-native way to preserve an RDS snapshot long-term with minimal operational overhead.

Incremental Exports: Exporting DynamoDB data directly to Amazon S3 provides an automated, serverless way to make data available for analytics without operational overhead.

Analytics-Friendly Storage: Amazon S3 supports long-term analytics workloads and can integrate with tools like Athena or QuickSight.

DynamoDB Export to S3 Documentation

Amazon FSx for Lustreis a high-performance, fully managed file system that is ideal for applications requiring low-latency access to shared storage, especially in use cases like gaming where high throughput and low latency are essential. It integrates easily with EC2 instances, providing fast and scalable shared storage, and supports custom protocols for specific application needs.

Option A (FSx File Gateway): FSx File Gateway is designed for hybrid cloud storage and is not suited for high-performance gaming workloads.

Option B (EC2 Windows instance): Setting up a file share on a Windows instance would introduce additional administrative overhead and would not provide the necessary performance.

Option C (EFS with Lustre): While Lustre is integrated with FSx, EFS does not natively support Lustre.

AWS References:

Amazon FSx for Lustre

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.

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

The best practice to securely provide short-term access to AWS resources, such as Amazon S3, without using long-term credentials, is to use AWS Security Token Service (STS). According to the AWS IAM Best Practices and the Security Pillar of the AWS Well-Architected Framework, temporary credentials should always be used over long-term credentials when possible.

From AWS IAM Documentation:

“Use temporary credentials (IAM roles and AWS STS) instead of long-term access keys. Temporary security credentials are short-term, automatically expire, and are retrieved using AWS STS.”

(Source: IAM Best Practices – IAM User Guide)

Option D outlines the use of a trust relationship and assume-role mechanism via AWS STS. This allows the on-premises application to request temporary, scoped-down credentials to upload files to S3 securely. This approach is:

Secure – Uses short-lived credentials with least privilege

Scalable – No need for EC2 or VPN tunnels

Low Operational Overhead – No infrastructure to maintain

AWS-Recommended – Aligned with security best practices

In contrast:

Option A uses long-term credentials, which is a security risk.

Option B requires additional infrastructure (EC2, VPN), increasing complexity and cost.

Option C relies on IP-based access, which is insecure and not a form of identity-based authentication.

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.

AWS Lambda for Operational Efficiency:

AWS Lambdais a serverless compute service that allows you to run code without provisioning or managing servers. It automatically scales based on the number of invocations and eliminates the need to maintain and monitor EC2 instances, making it far more operationally efficient compared to running a cron job on EC2.

By using Lambda, you pay only for the compute time that your function uses. This is especially beneficial when dealing with lightweight tasks, such as scanning a DynamoDB table and sending email messages once a day.

Amazon DynamoDB:

DynamoDBis a highly scalable, fully managed NoSQL database. The table stores employee start dates, and scanning the table to find the employees who have a work anniversary on the current day is a lightweight operation. Lambda can easily perform this operation using theDynamoDB Scan APIor queries, depending on how the data is structured.

Amazon SNS for Email Notifications:

Amazon Simple Notification Service (SNS)is a fully managed messaging service that supports sending notifications to a variety of endpoints, including email. SNS is well-suited for sendingout email messages to employees, as it can handle the fan-out messaging pattern (sending the same message to multiple recipients).

In this scenario, once Lambda identifies employees who have their work anniversaries, it can use SNS to send the email notifications efficiently. SNS integrates seamlessly with Lambda, and sending emails via SNS is a common pattern for this type of use case.

Event Scheduling:

To automate this daily task, you can schedule the Lambda function usingAmazon EventBridge (formerly CloudWatch Events). EventBridge can trigger the Lambda function on a daily schedule (cron-like scheduling). This avoids the complexity and operational overhead of manually setting up cron jobs on EC2 instances.

Why Not EC2 or SQS?:

Option A & Bsuggest running a cron job on anAmazon EC2instance. This approach requires you to manage, scale, and patch the EC2 instance, which increases operational overhead. Lambda is a better choice because it automatically scales and doesn’t require server management.

Amazon Simple Queue Service (SQS)is ideal for decoupling distributed systems but isn’t necessary in this context because the goal is to send notifications to employees on their work anniversaries. SQS adds unnecessary complexity for this straightforward use case, whereSNSis the simpler and more efficient solution.

AWS References:

AWS Lambda

Amazon SNS

Amazon DynamoDB

Amazon EventBridge

Summary:

UsingAWS Lambdacombined withAmazon SNSto send notifications, and scheduling the function withAmazon EventBridgeto run daily, is the most operationally efficient solution. It leverages AWS serverless technologies, which reduce the need for infrastructure management and provide automatic scaling. Therefore,Option Cis the correct and optimal choice.