A company wants to build a logging solution for its multiple AWS accounts.

Understanding the Requirement: The company needs logs to be highly available for 30 days for frequent analysis, retained for an additional 60 days for backup, and deleted after 90 days.

Analysis of Options:

Transition to S3 Standard after 30 days: Keeps logs in the same high-availability storage, not cost-effective.

Transition to S3 Standard-IA, then Glacier Flexible Retrieval after 90 days: Adds unnecessary cost and complexity since objects need to be accessible for only 30 days and then retained for 60 days.

Transition to Glacier Flexible Retrieval after 30 days: Not suitable for frequent access required in the first 30 days.

Transition to S3 One Zone-IA after 30 days, then Glacier Flexible Retrieval: Provides cost-effective storage for infrequently accessed logs after the initial 30-day period, then moves to the cheapest long-term storage before deletion.

Best Solution:

Transition to S3 One Zone-IA after 30 days, then Glacier Flexible Retrieval: This solution meets the requirements for high availability, cost-effective storage for backup, and scheduled deletion with the least cost.