AWS Certified Solutions Architect – Associate (SAA-C03)Design Cost-Optimized ArchitecturesMedium
A data analytics startup processes large volumes of IoT sensor data continuously. The data is initially stored in Amazon S3 and then processed by an AWS Lambda function. The Lambda function needs to retrieve small objects (less than 1 MB) from S3 frequently, often multiple times per second. The company wants to optimize the data transfer costs between S3 and Lambda. What is the most cost-effective architectural pattern to achieve this?
- AUse Amazon CloudFront as a cache in front of the S3 bucket.
- BStore S3 objects and Lambda function in separate AWS Regions.
- CEnsure the S3 bucket and Lambda function are in the same AWS Region.
- DUse S3 Transfer Acceleration for data transfer between S3 and Lambda.
Show answer & explanationAnswer & explanation
Correct answer: C. Ensure the S3 bucket and Lambda function are in the same AWS Region.
Data transfer between S3 and Lambda within the same AWS Region is free. Placing the S3 bucket and Lambda function in the same Region eliminates data transfer costs for this interaction, which is critical for frequently accessed small objects.
Why the other options are wrong
- A. CloudFront is for content delivery to end-users globally and would incur additional costs without solving the internal S3-Lambda data transfer cost issue.
- B. Storing in separate Regions will incur significant cross-Region data transfer costs.
- D. S3 Transfer Acceleration speeds up transfers over long distances but does not eliminate data transfer costs, especially within AWS.
AWS Same-Region Data Transfer Cost
Data transfer between AWS services within the same AWS Region is generally free of charge, especially for services like S3 and Lambda. This is a key cost optimization strategy for inter-service communication.
- Data transfer between AWS services in the same Region is often free.
- Reduces network latency.
- Critical for optimizing costs in event-driven or microservices architectures.
Memory trick: Same Region, same team, no transfer fee scheme.