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

The requirement is secure, permanent connectivity to two VPCs without enabling VPC-to-VPC communication. Option B achieves this by establishing a separate Site-to-Site VPN connection between the remote office and each VPC. Updating each VPC’s route tables ensures traffic from the remote office reaches the correct VPC resources, while preventing routing between the VPCs themselves. Options involving transit gateways (A and D) would introduce transitive routing capabilities, which violates the requirement of isolation between VPCs. Option C (VPC peering) directly conflicts with the requirement by enabling cross-VPC access. Therefore, option B is the correct solution as it maintains isolation while providing secure VPN connectivity.

AWS Step Functions is designed to coordinate multiple AWS services into serverless workflows, handling errors, retries, and complex logic. By configuring Amazon S3 Event Notifications to trigger an Amazon EventBridge rule, you can automatically start a Step Functions workflow when a new object is uploaded to S3. Step Functions can manage retries for failed uploads and orchestrate calls to various AWS services with minimal operational effort.

AWS Documentation Extract:

“You can use Amazon EventBridge to initiate AWS Step Functions workflows in response to events from S3 buckets. Step Functions can orchestrate the sequence of AWS service calls and automatically handle retries and errors, making it ideal for automating and managing complex workflows.”

(Source: AWS Step Functions documentation, Using Step Functions with EventBridge and S3)

Other options:

A: Requires manual implementation of orchestration and error handling.

B & C: Involve additional infrastructure management and custom logic for workflow orchestration and error handling, increasing operational effort.

A. Fixed desired instances:Does not adapt to traffic load fluctuations, leading to inefficiencies.

B. Larger EC2 instances:Increases costs unnecessarily.

C. Target tracking scaling policy:Adjusts capacity based on actual demand, optimizing costs.

D. Instance store volumes:Not persistent and unsuitable for shared data across instances.

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

From AWS Documentation:

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

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

Why B is correct:

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

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

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

Why others are incorrect:

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

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

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

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

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

Amazon 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​.

To automatically identify sensitive data in Amazon S3 and monitor access patterns for suspicious activities:

Amazon Macie uses machine learning and pattern matching to discover and protect sensitive data in S3. It provides visibility into data security risks and enables automated protection against those risks.

Amazon GuardDuty is a threat detection service that continuously monitors for malicious activity and unauthorized behavior to protect AWS accounts and workloads. It analyzes events from AWS CloudTrail, VPC Flow Logs, and DNS logs.

By enabling both services, the company can automate the discovery of sensitive data and continuously monitor access patterns for potential security threats.

AWS VPC endpoints (interface and gateway) allow private connectivity from VPC resources to AWS services without requiring public IP addresses or internet gateways. This ensures applications remain isolated in private subnets while securely accessing AWS services. NAT gateways (B) would allow internet access, which does not meet the security requirement. Internet gateways (C) directly expose traffic to the internet, which violates the isolation requirement. Direct Connect (D) connects on-premises environments to AWS but does not provide service access from private subnets. Therefore, option A — using interface VPC endpoints — is the correct solution.

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

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

Other Options:

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

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

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

AWS References:

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

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

IAM Role: Attaching an IAM role to an EC2 instance profile is a secure way to manage permissions without embedding credentials.

AWS Secrets Manager: Grants controlled access to database credentials and automatically rotates secrets if configured.

Identity-Based Policy: Ensures the IAM role only has access to specific secrets, enhancing security.

AWS Secrets Manager Documentation

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.

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

This protects against:

Data center failure

Device failure

Location outages

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

— AWS Direct Connect Resiliency Recommendations

Option C follows AWS maximum resiliency model.