Amazon Web Services Updated SAA-C03 Exam Questions and Answers by amari

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.

The issue in this case is related to the processing tier, where EC2 instances are overwhelmed at peak times, causing delays.Option D, using anAmazon EC2 Auto Scaling target tracking policybased on theApproximateNumberOfMessagesin the SQS queue, is the best solution.

Auto Scaling with Target Tracking:

Target tracking policiesdynamically scale out or in based on a specific metric. For this use case, you can monitor theApproximateNumberOfMessagesin the SQS queue. When the number of messages (orders) in the queue increases, the Auto Scaling group will scale out more EC2 instances to handle the additional load, ensuring that the queue doesn’t build up and cause delays.

This solution is ideal for handling variable and unpredictable peak times, as Auto Scaling can automatically adjust based on real-time load rather than scheduled times.

Why Not the Other Options?:

Option A (Scheduled Scaling): Scheduled scaling works well for predictable peak times, but this company experiencesunpredictable peak usage, making scheduled scaling less effective.

Option B (ElastiCache for Redis): Adding a caching layer would help if DynamoDB were the bottleneck, but in this case, the issue is CPU overload on EC2 instances in the processing tier.

Option C (CloudFront): CloudFront would help cache static content from the web tier, but it wouldn’t resolve the issue of the processing tier’s overloaded EC2 instances.

AWS References:

Amazon EC2 Auto Scaling Target Tracking

Amazon SQS ApproximateNumberOfMessages

Amazon Kinesis is the right streaming service because it ingests and processes data in real time. For the user-data store, Amazon DynamoDB is the correct database because AWS documents that DynamoDB is a serverless, fully managed, distributed NoSQL database with single-digit millisecond performance at any scale. That directly matches the durability, low-latency, and unknown-scale requirements in the question. RDS is not the most natural fit for unpredictable massive serverless scaling here, while CloudFront and Global Accelerator solve delivery and network-edge problems rather than real-time event ingestion plus low-latency persistence. For a serverless analytics application with streaming game data and highly scalable user storage, Kinesis and DynamoDB are the best pair.

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The requirement calls for three capabilities at fleet scale: (1) regular security/vulnerability scanning of EC2 instances, (2) scheduled patching, and (3) reporting on patch compliance/status. The AWS-managed services designed for this are Amazon Inspector for vulnerability scanning and AWS Systems Manager Patch Manager for patch orchestration and compliance reporting.

Amazon Inspector provides automated vulnerability management that can assess EC2 instances for software vulnerabilities and exposure, producing findings that identify missing patches and vulnerable packages. This addresses the security scanning portion without requiring custom tooling on each instance beyond standard agent/configuration requirements.

Systems Manager Patch Manager allows you to define patch baselines, schedule patching operations via maintenance windows, and apply patches across large fleets in a controlled manner. Patch Manager also provides compliance views and reporting so you can see which instances are compliant, which are missing patches, and the results of patch operations. This directly meets the need to patch “on a regular schedule” and to “provide a report of each instance’s patch status.”

The other options are mismatched services: Macie focuses on discovering and protecting sensitive data (especially in S3), not scanning EC2 for software vulnerabilities. GuardDuty is for threat detection based on logs and events; it is not an EC2 vulnerability scanner and does not function as a patching orchestrator. Detective helps investigate security events and relationships; it is not a vulnerability scanning or patch deployment tool. Additionally, cron jobs on each instance create high operational overhead and inconsistent reporting—exactly what the company wants to avoid.

Therefore, D is the correct, operationally excellent approach: use Inspector for vulnerability scanning and Systems Manager Patch Manager for automated, scheduled patching with centralized compliance reporting.