While preparing for the AWS SAA-C03 exam, many candidates get confused by S3 storage tier selection. In the real world, this is fundamentally a decision about balancing frequent access needs in the short term versus cost-effective long-term retention. Let’s drill into a simulated scenario.
The Scenario #
Cloud Atlas Inc., a SaaS company specializing in geospatial analytics, needs to manage backups of their user reports data. The data is stored in Amazon S3 using the Standard storage class because the reports are frequently accessed during the first 30 days after creation for immediate analytics validation. After 30 days, the reports are rarely accessed but must be retained indefinitely for compliance reasons.
Key Requirements #
Design a cost-optimized S3 storage strategy that accommodates frequent access within the first month, followed by long-term archival storage with minimal cost, while ensuring indefinite data retention.
The Options #
- A) Enable S3 Intelligent-Tiering to automatically move objects between frequent and infrequent access tiers based on usage.
- B) Create an S3 Lifecycle policy to transition objects from S3 Standard to S3 Glacier Deep Archive exactly 30 days after creation.
- C) Create an S3 Lifecycle policy to transition objects from S3 Standard to S3 Standard-Infrequent Access (S3 Standard-IA) after 30 days.
- D) Create an S3 Lifecycle policy to transition objects from S3 Standard to S3 One Zone-Infrequent Access (S3 One Zone-IA) after 30 days.
Correct Answer #
B) Create an S3 Lifecycle policy to transition objects from S3 Standard to S3 Glacier Deep Archive exactly 30 days after creation.
The Architect’s Analysis #
Correct Answer #
Option B
Step-by-Step Winning Logic #
S3 Glacier Deep Archive provides the most cost-effective long-term storage option for data that is infrequently or never accessed after a fixed period but must be retained indefinitely. Since the data is frequently accessed only during the first 30 days, keeping it in S3 Standard makes sense initially. Transitioning to Glacier Deep Archive after 30 days minimizes storage cost while complying with retention requirements. The trade-off is slower retrieval times and potential retrieval costs when the data is accessed, but because data access is expected to cease, this is acceptable.
The Traps (Distractor Analysis) #
- Why not A? Intelligent-Tiering automatically moves data between frequent and infrequent access tiers but does not move data to archive classes like Glacier Deep Archive, so long-term cost savings are limited.
- Why not C? Standard-IA is cheaper than Standard for infrequent access, but still significantly more expensive than Glacier Deep Archive for long-term retention.
- Why not D? One Zone-IA reduces availability and resilience by storing data in a single Availability Zone, posing a risk for important archived backups, which should be avoided for compliance data.
The Architect Blueprint #
Mermaid Diagram illustrating lifecycle transition from S3 Standard to Glacier Deep Archive
Diagram Note: User applications access reports frequently in S3 Standard for the first month; after 30 days, lifecycle rules move reports into Glacier Deep Archive for cost-effective indefinite retention.
Real-World Practitioner Insight #
Exam Rule #
For the exam, always pick S3 Glacier Deep Archive when the data must be retained indefinitely with minimal or no access after a short frequent access window.
Real World #
In production, organizations often combine lifecycle policies with Intelligent-Tiering for nuanced usage patterns or compliance-driven delays, but for pure archival with strict retention, Glacier Deep Archive is unbeatable on cost.