Design Cost-Optimized Architectures

1. A company stores application logs in Amazon S3. Logs are frequently accessed for the first 30 days, rarely accessed for the next 60 days, and never accessed after 90 days. Which S3 Lifecycle configuration minimizes storage costs?

• A.Transition objects to S3 Standard-IA after 30 days, then to S3 Glacier Flexible Retrieval after 90 days, and expire them after 180 days to balance cost and retrieval needs.
• B.Transition objects to S3 Standard-IA after 30 days, transition to S3 Glacier Deep Archive after 90 days, and expire (delete) after 90 days total to eliminate storage costs entirely.✓ Correct
• C.Keep all objects in S3 Standard throughout their lifecycle because retrieval fees from Glacier tiers would negate any storage savings for frequently accessed data.
• D.Transition objects immediately to S3 Glacier Deep Archive on creation to achieve the lowest possible storage price regardless of access frequency.

2. An architect sets up an S3 Lifecycle rule to transition objects to S3 Glacier Flexible Retrieval after 1 day. The objects are typically 128 KB in size. What cost concern should the architect be aware of?

• A.S3 Glacier Flexible Retrieval does not support objects smaller than 1 MB, so objects smaller than this threshold will be automatically rejected and deleted by AWS.
• B.Objects smaller than 128 KB stored in Glacier are billed at a minimum of 128 KB, so tiny objects may cost more in Glacier than in S3 Standard due to the minimum size overhead.
• C.There is a mandatory 30-day minimum storage duration in S3 Standard before objects can be transitioned, so a 1-day rule will fail silently and objects will remain in Standard.
• D.Glacier Flexible Retrieval charges a per-object overhead fee for each archived object, and very small objects (under 128 KB) are billed as if they were 128 KB, making bulk archival of small objects potentially more expensive than S3 Standard.✓ Correct

3. A media company uploads user-generated content to Amazon S3. Access patterns for individual files are unpredictable — some files are accessed frequently, others are never accessed again after upload. Which S3 storage class BEST optimizes cost without requiring the team to define lifecycle rules?

• A.S3 Standard-IA is best because it charges a lower storage price than Standard and is designed for infrequently accessed data, regardless of access pattern predictability.
• B.S3 Glacier Instant Retrieval is best because it provides the lowest latency retrieval of all archive tiers, making it suitable for any unpredictable access pattern.
• C.S3 Intelligent-Tiering automatically moves objects between access tiers based on actual usage, eliminating the need to predict access patterns while optimizing cost.✓ Correct
• D.S3 One Zone-IA is best because it reduces cost by storing data in a single Availability Zone, making it ideal for user-generated content that changes frequently.

4. A team is evaluating S3 Intelligent-Tiering for objects averaging 5 KB in size. A solutions architect notes a concern. What is the key cost consideration for using Intelligent-Tiering with very small objects?

• A.Intelligent-Tiering cannot store objects smaller than 128 KB; AWS automatically upgrades small objects to S3 Standard, resulting in higher costs than expected.
• B.Intelligent-Tiering charges a per-object monitoring and automation fee for each object regardless of size, making it cost-ineffective for large numbers of very small objects.✓ Correct
• C.Intelligent-Tiering requires a minimum 90-day commitment before it begins monitoring access patterns, meaning small objects deleted before 90 days incur early deletion charges.
• D.Intelligent-Tiering encrypts all small objects by default using SSE-S3, which adds a per-request encryption charge that outweighs the tiering savings for small objects.

5. A financial services firm must archive 10 years of transaction records. Records must be retrievable within 12 hours if auditors request them, and storage cost must be minimized. Which S3 Glacier tier should the architect choose?

• A.S3 Glacier Instant Retrieval provides millisecond access to archived data and is the right choice when any retrieval latency is unacceptable for compliance or audit scenarios.
• B.S3 Glacier Flexible Retrieval offers retrieval in minutes to hours (Expedited: 1-5 min, Standard: 3-5 hrs, Bulk: 5-12 hrs) at low cost, satisfying the 12-hour SLA at minimal expense.
• C.S3 Glacier Deep Archive provides retrieval in 12-48 hours and is the lowest-cost Glacier option; it satisfies the 12-hour requirement using Bulk retrieval and costs less than Flexible Retrieval.✓ Correct
• D.S3 Standard-IA is the correct choice because Glacier tiers are unsuitable for compliance workloads requiring guaranteed retrieval SLAs under 24 hours.