SAA-C03 Exam Dumps - AWS Certified Solutions Architect - Associate (SAA-C03)

Amazon DocumentDB serverless is the most cost-effective managed option for this workload because the data is document-oriented, documents frequently exceed 1 MB, and usage changes significantly between market hours and off-hours. DocumentDB supports larger document sizes than DynamoDB items, while DynamoDB has a 400 KB item size limit and is therefore unsuitable for documents frequently larger than 1 MB. Serverless capacity scaling allows the database to scale up during high-volume trading periods and scale down during quiet periods, reducing wasted provisioned capacity. RDS Reserved Instances still require fixed capacity and are less suitable for document-style workloads. Self-managed MongoDB on EC2 increases operational overhead and is not the best managed AWS architecture.

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.

CloudFront requires ACM certificates to be created in us-east-1. Origin Access Control (OAC) securely allows CloudFront to upload objects to S3 without exposing the bucket publicly. Transfer Acceleration and S3 website endpoints are unnecessary or incompatible for this use case.

AWS Backup is a fully managed backup service that can create backup plans for EC2 instances, including both instance configurations and attached EBS volumes, with scheduled and cross-Region copy capabilities. By adding the EC2 instances to the resource assignment in the backup plan, AWS Backup automatically backs up all configurations and attached EBS volumes, and can copy backups to a secondary Region for disaster recovery, providing the highest operational efficiency with the least manual effort.

AWS Documentation Extract:

“AWS Backup provides fully managed backup for EC2 instances and attached EBS volumes, with scheduling, retention, and cross-Region copy built in. By adding the EC2 instance as a resource, the backup includes both configuration and attached volumes.”

(Source: AWS Backup documentation)

A, D: Custom Lambda scripts increase operational overhead and are not as integrated or robust as AWS Backup.

C: Assigning only EBS volumes does not include the EC2 instance configuration, which is needed for full recovery.

Key Requirements:

Handle traffic spikes efficiently and reduce latency caused by cold starts.

Optimize costs during low traffic periods.

Analysis of Options:

Option A:

Provisioned Concurrency:Reduces cold start latency by pre-warming Lambda environments for the required number of concurrent executions.

AWS Application Auto Scaling:Automatically adjusts provisioned concurrency based on demand, ensuring cost optimization by scaling down during low traffic.

Correct Approach:Provides a balance between performance during traffic spikes and cost optimization during idle periods.

Option B:

Using EC2 instances with Auto Scaling introduces unnecessary complexity for a serverless architecture. It requires additional management and does not address the issue of cold starts for Lambda.

Incorrect Approach:Contradicts the serverless design philosophy and increases operational overhead.

Option C:

Setting a fixed concurrency level ensures performance during spikes but does not optimize costs during low traffic. This approach would maintain provisioned instances unnecessarily.

Incorrect Approach:Lacks cost optimization.

Option D:

Using EventBridge Scheduler for periodic invocations may reduce cold starts but does not dynamically scale based on traffic demand. It also leads to unnecessary invocations during idle times.

Incorrect Approach:Suboptimal for high traffic fluctuations and cost control.

AWS Solution Architect References:

AWS Lambda Provisioned Concurrency

AWS Application Auto Scaling with Lambda

To serve a static website hosted in Amazon S3 over HTTPS, you must use Amazon CloudFront because S3 does not natively support HTTPS for static website endpoints.

Steps to meet HTTPS requirement:

B. Create a CloudFront distribution and configure the S3 bucket as the origin. This enables global edge caching and performance optimization.

D. Attach an SSL/TLS certificate (typically from AWS Certificate Manager) to the CloudFront distribution to handle HTTPS connections.

S3 buckets used as static website hosts only support HTTP directly. While S3 supports HTTPS for REST API access, it does not support HTTPS on static website endpoints.

This setup aligns with security best practices and supports the Secure and Operational Excellence pillars of the AWS Well-Architected Framework.

🔗 References:

Hosting a static website using Amazon S3 and CloudFront

CloudFront + HTTPS with ACM

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.

Because the application is public and serves global customers with dynamic IP addresses, the web tier must allow HTTPS traffic from0.0.0.0/0on port 443. For the database tier, the secure design is to allow MySQL access only from theweb tier’s security group, not from the internet. AWS RDS documentation explains that you can specify another VPC security group as the source for the DB security group, which allows application servers to connect without exposing the database publicly. That makes A the correct configuration. Options B and C do not work well for global dynamic users, and D exposes the database to the internet.

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