SOA-C02 Cost and Performance Optimization Practice Question

A company stores application logs in Amazon S3. The logs are rarely accessed after the first 30 days, but must be retained for 7 years for compliance. The SysOps administrator wants to minimize storage costs while ensuring logs are available for retrieval within 12 hours if needed. Which S3 lifecycle configuration is the most cost-effective?

⚠ Common exam trap

Test-takers frequently choose S3 Glacier (Flexible Retrieval) because it is a well-known archival tier, but they overlook the specific 12-hour retrieval requirement and the lower cost of Glacier Deep Archive for long-term retention.

Answer choices

Why each option matters

Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.

Correct answer & explanation

✓

S3 Standard for 30 days, then transition to S3 Glacier Deep Archive

It transitions logs from S3 Standard (for frequent access during the first 30 days) to S3 Glacier Deep Archive, which offers the lowest storage cost for long-term retention. Since logs must be retained for 7 years and only need retrieval within 12 hours, Glacier Deep Archive's 12-hour standard retrieval time meets the requirement while minimizing costs.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

✓
S3 Standard for 30 days, then transition to S3 Glacier Deep Archive
Why this is correct
This is the most cost-effective lifecycle policy for logs that are frequently accessed for the first 30 days but rarely read afterward. A lifecycle rule can automatically transition objects to S3 Glacier Deep Archive after 30 days, where storage costs just $0.00099 per GB-month. Even though standard retrieval can take up to 12 hours, that is acceptable for compliance log analysis that is not time-sensitive.
✗
S3 Standard for 30 days, then transition to S3 Glacier (Flexible Retrieval)
Why it's wrong here
S3 Glacier (Flexible Retrieval) provides lower storage cost than S3 Standard but is significantly more expensive than Glacier Deep Archive, charging around $0.0036 per GB-month. Its primary advantage—retrieval in minutes to hours—is unnecessary for logs that are only needed for occasional compliance or audit requests. Therefore, choosing it over Deep Archive incurs higher long-term storage costs without a meaningful operational benefit.
✗
Use S3 Intelligent-Tiering from the start
Why it's wrong here
S3 Intelligent-Tiering automates movement between access tiers, but it is not the cheapest option for data with a predictable access pattern like these logs. It charges a monthly monitoring and automation fee per object, typically $0.0025 per 1,000 objects, plus the cost of the frequent access tier while objects remain there. For logs that are known to become cold after 30 days, a direct lifecycle transition to Deep Archive avoids those ongoing per-object charges.
✗
S3 Standard for 30 days, then transition to S3 One Zone-IA
Why it's wrong here
S3 One Zone-IA stores data only within a single Availability Zone, so it lacks the multi-AZ redundancy and 99.999999999% (11 nines) durability expected for compliance retention logs. It also incurs a per-GB retrieval fee that can be substantial if logs are later accessed for audits. The lower storage price compared to S3 Standard does not justify losing zone-level resilience for long-term regulatory data.

Quick reference

AWS S3 Storage Class Comparison

Storage Class	Min Duration	Retrieval	Use Case
S3 Standard	None	Immediate	Frequently accessed data
S3 Standard-IA	30 days	Immediate	Infrequent access, rapid retrieval
S3 One Zone-IA	30 days	Immediate	Non-critical infrequent data
S3 Intelligent-Tiering	None	Immediate–hours	Unknown or changing access patterns
S3 Glacier Instant	90 days	Milliseconds	Archive with instant retrieval
S3 Glacier Flexible	90 days	Minutes–hours	Archive, flexible retrieval
S3 Glacier Deep Archive	180 days	Hours	Long-term compliance archive

Go deeper

SOA-C02 Cost and Performance Optimization Practice Question

Why each option matters

Option-by-option breakdown

AWS S3 Storage Class Comparison

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