Amazon SAA-C03 Exam Dumps

Using Amazon CloudFront in front of an ALB in a single region is a cost-effective way to deliver content with low latency across the globe. CloudFront caches content closer to the users, reducing the load on backend servers and minimizing data transfer costs by serving cached content from edge locations.

Compared to Global Accelerator, CloudFront is significantly more cost-optimized for static and dynamic content delivery. Multi-region deployments increase infrastructure and transfer costs, which violates the optimization goal. Therefore, option A provides the best mix of performance and cost efficiency.

AWS recommends using Amazon ElastiCache as an in-memory caching layer in front of relational databases such as Amazon RDS to offload read traffic and significantly improve performance for read-heavy workloads. ElastiCache (Redis OSS) provides microsecond latency and can cache the results of frequent or expensive queries without requiring any change to the underlying database schema or engine. This directly addresses the requirement to improve performance without changing the database structure and with minimal operational overhead, because ElastiCache is a fully managed service (patching, failure detection, replacement, etc., are handled by AWS).

Option A (DynamoDB) would require a full data migration and application changes, including schema and query rewrites.

Option C (Memcached on EC2) introduces additional management overhead for EC2 instances (scaling, patching, HA).

Option D (DAX) is a caching layer only for DynamoDB and cannot be used directly with Amazon RDS.

To run RDS instances only during business hours with the least operational overhead, you can useAmazon EventBridgeto schedule events that invokeAWS Lambda functions. The Lambda functions can be configured to start and stop the RDS instances based on the specified schedule (business hours). EventBridge rules allow you to define recurring events easily, and Lambda functions provide a serverless way to manage RDS instance start and stop operations, reducing administrative overhead.

Option A: While CloudWatch alarms could be used, they are more suited for monitoring, and using Lambda with EventBridge is simpler.

Option B (Trusted Advisor): Trusted Advisor is not ideal for scheduling tasks.

Option C (Systems Manager): Systems Manager could also work, but EventBridge and Lambda offer a more streamlined and lower-overhead solution.

AWS Reference:

Amazon EventBridge Scheduler

AWS Lambda

Using API Gateway with API keys provides secure access control. Amazon SQS allows asynchronous decoupling between frontend and backend, ensuring that backend processing can scale independently. AWS Lambda reading from SQS ensures scalable, event-driven processing with minimal operational management. This architecture is resilient and decoupled.

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Amazon RDS Blue/Green Deployments provide a safe and straightforward way to make database changes with minimal downtime and risk. Blue/Green deployments create an exact copy ('green') of your production environment ('blue') where you can make schema changes and run tests. After validation, you can promote the green environment to production with a single click or API call, achieving near-zero downtime and maximum availability. This is the AWS-recommended method for deploying major database changes in a way that minimizes impact to users and maximizes uptime.

Reference Extract from AWS Documentation / Study Guide:

'Amazon RDS Blue/Green Deployments enable you to make changes to your database environment safely. You can perform schema updates and feature testing in a fully managed staging environment and switch over with minimal downtime, ensuring the highest availability.'

Source: AWS Certified Solutions Architect -- Official Study Guide, Database and Migration section; Amazon RDS Blue/Green Deployments Documentation.