Amazon S3 Durability & Availability | Overview.

Amazon S3  Durability & Availability - Overview.

Scope:

• Intro
• Durability,
• Availability,
• Key Differences,
• Best Practices.

Intro:

• Amazon S3 (Simple Storage Service) is designed for high durability and availability, making it ideal for storing critical data. 

Here’s a breakdown:

1. Durability

 Durability: 99.999999999% (11 9’s)

•         This means that if twtech stores 10 million objects, on average twtech may lose one object every 10,000 years.
•         Achieved through automatic replication across multiple facilities within a region.
•         Data integrity is maintained using regular checksums and self-healing processes.
•         Designed for long-term storage of critical data like backups, logs, and archives.

2. Availability

Availability varies slightly depending on the S3 storage class:

Storage Class	Availability SLA	Use Case
S3 Standard	99.99%	Frequently accessed data
S3 Standard-IA	99.9%	Infrequently accessed data
S3 One Zone-IA	99.5%	Infrequently accessed data in a single AZ
S3 Glacier Instant Retrieval	99.9%	Archival data with milliseconds retrieval
S3 Glacier Flexible Retrieval	99.99% (durability)	Archival data, minutes to hours retrieval
S3 Glacier Deep Archive	99.99% (durability)	Long-term archival (12+ hours retrieval)

3. Key Differences

•         Durability is about data loss prevention.
•         Availability is about data access uptime.
•         Even if S3 is down temporarily (availability issue), twtech data is not lost (durability is still maintained).

4. Best Practices

•         Use S3 Standard for mission-critical applications needing high availability.
•         Enable S3 Versioning and Replication for extra protection and disaster recovery.
•         Monitor with S3 Event Notifications and CloudWatch for operational insights.