AWS-S3: Storage classes

Amazon S3 offers a range of storage classes designed for different use cases. These include S3 Standard for general-purpose storage of frequently accessed data; S3 Intelligent-Tiering for data with unknown or changing access patterns; S3 Standard-Infrequent Access (S3 Standard-IA) and S3 One Zone-Infrequent Access (S3 One Zone-IA) for long-lived, but less frequently accessed data; and Amazon S3 Glacier (S3 Glacier) and Amazon S3   Glacier Deep Archive (S3 Glacier Deep Archive) for long-term archive and digital preservation. Amazon S3 also offers capabilities to manage your data throughout its lifecycle. Once an S3 Lifecycle policy is set, your data will automatically transfer to a different storage class without any changes to your application. 

imagr source: www.javatpoint.com

Most of the exam questions on S3 will revolve around which storage class to use given a particular type of data scenario. You may be asked like “when these files are 30 days old, they are infrequently accessed and after 90 days they are not used at all, which storage class an architect should use with what lifecycle policy.”

You might have answer option like “move it to this to S3-infrequently accessed tier, when it's 30 days old, and after 90 days archive it off to glacier."

Let’s look at available storage classes in detail:

Amazon S3 Standard (S3 Standard): It is the general purpose storage class for S3 for regular uses.

Key features:

• Low latency and high throughput performance
• Designed for durability of 99.999999999% of objects across multiple Availability Zones
• Resilient against events that impact an entire Availability Zone
• Designed for 99.99% availability over a given year
• Supports SSL for data in transit and encryption of data at rest
• S3 Lifecycle management for automatic migration of objects to other S3 Storage Classes 

Amazon S3 Intelligent-Tiering (S3 Intelligent-Tiering): The S3 Intelligent-Tiering storage class is designed to optimize costs by automatically moving data to the most cost-effective access tier, without performance impact or operational overhead. It works by storing objects in two access tiers: one tier that is optimized for frequent access and another lower-cost tier that is optimized for infrequent access. For a small monthly monitoring and automation fee per object, Amazon S3 monitors access patterns of the objects in S3 Intelligent-Tiering, and moves the ones that have not been accessed for 30 consecutive days to the infrequent access tier. If an object in the infrequent access tier is accessed, it is automatically moved back to the frequent access tier. There are no retrieval fees when using the S3 Intelligent-Tiering storage class, and no additional tiering fees when objects are moved between access tiers.

S3 Storage Classes can be configured at the object level and a single bucket can contain objects stored in S3 Standard, S3 Intelligent-Tiering, S3 Standard-IA, and S3 One Zone-IA. You can upload objects directly to S3 Intelligent-Tiering, or use S3 Lifecycle policies to transfer objects from S3 Standard and S3 Standard-IA to S3 Intelligent-Tiering. You can also archive objects from S3 Intelligent-Tiering to S3 Glacier.

It might seem to you that it is best to use this storage class as it takes care of movement itself based on data access frequency. But it costs a small monitoring fee also, so in case you know your data access pattern exactly, it would not be most cost-effective.

Key Features:

• Same low latency and high throughput performance of S3 Standard
• Small monthly monitoring and auto-tiering fee
• Automatically moves objects between two access tiers based on changing access patterns
• Designed for durability of 99.999999999% of objects across multiple Availability Zones
• Resilient against events that impact an entire Availability Zone
• Designed for 99.9% availability over a given year
• Supports SSL for data in transit and encryption of data at rest
• S3 Lifecycle management for automatic migration of objects to other S3 Storage Classes

 

Amazon S3 Standard-Infrequent Access (S3 Standard-IA): S3 Standard-IA is for data that is accessed less frequently, but requires rapid access when needed. S3 Standard-IA offers the high durability, high throughput, and low latency of S3 Standard, with a low per GB storage price and per GB retrieval fee. This combination of low cost and high performance make S3 Standard-IA ideal for long-term storage, backups, and as a data store for disaster recovery files.

 Key Features:

• Same low latency and high throughput performance of S3 Standard
• Data is resilient in the event of one entire Availability Zone destruction
• Designed for 99.9% availability over a given year
• Supports SSL for data in transit and encryption of data at rest
• S3 Lifecycle management for automatic migration of objects to other S3 Storage Classes

Amazon S3 One Zone-Infrequent Access (S3 One Zone-IA): S3 One Zone-IA is for data that is accessed less frequently, but requires rapid access when needed but unlike other S3 Storage Classes which store data in a minimum of three Availability Zones (AZs), S3 One Zone-IA stores data in a single AZ and costs 20% less than S3 Standard-IA. S3 One Zone-IA is ideal for customers who want a lower-cost option for infrequently accessed data but do not require the availability and resilience of S3 Standard or S3 Standard-IA. It’s a good choice for storing secondary backup copies of on-premises data or easily re-creatable data. You can also use it as cost-effective storage for data that is replicated from another AWS Region using S3 Cross-Region Replication.

S3 One Zone-IA offers the same high durability†, high throughput, and low latency of S3 Standard, with a low per GB storage price and per GB retrieval fee.

Key Features:

• Same low latency and high throughput performance of S3 Standard
• Designed for 99.5% availability over a given year
• Supports SSL for data in transit and encryption of data at rest
• S3 Lifecycle management for automatic migration of objects to other S3 Storage Classes

† Because S3 One Zone-IA stores data in a single AWS Availability Zone, data stored in this storage class will be lost in the event of Availability Zone destruction.

Archive

Amazon S3 Glacier (S3 Glacier): S3 Glacier is a secure, durable, and low-cost storage class for data archiving. You can reliably store any amount of data at costs that are competitive with or cheaper than on-premises solutions. You can upload objects directly to S3 Glacier, or use S3 Lifecycle policies to transfer data between any of the S3 Storage Classes for active data.

Key Features:

• Designed for durability of 99.999999999% of objects across multiple Availability Zones
• Data is resilient in the event of one entire Availability Zone destruction
• Supports SSL for data in transit and encryption of data at rest
• Low-cost design is ideal for long-term archive
• Configurable retrieval times, from minutes to hours
• S3 PUT API for direct uploads to S3 Glacier, and S3 Lifecycle management for automatic migration of objects

Amazon S3 Glacier Deep Archive (S3 Glacier Deep Archive): S3 Glacier Deep Archive is Amazon S3’s lowest-cost storage class and supports long-term retention and digital preservation for data that may be accessed once or twice in a year. It is designed for customers — particularly those in highly-regulated industries, such as the Financial Services, Healthcare, and Public Sectors — that retain data sets for 7-10 years or longer to meet regulatory compliance requirements.

Key Features:

• Designed for durability of 99.999999999% of objects across multiple Availability Zones
• Lowest cost storage class designed for long-term retention of data that will be retained for 7-10 years
• Ideal alternative to magnetic tape libraries
• Retrieval time within 12 hours
• S3 PUT API for direct uploads to S3 Glacier Deep Archive, and S3 Lifecycle management for automatic migration of objects

 

	S3 Standard	S3 Intelligent-Tiering	S3 Standard-IA	S3 One Zone-IA	S3 Glacier	S3 Glacier Deep Archive
Designed for durability	99.999999999% (11 9’s)	99.999999999% (11 9’s)	99.999999999% (11 9’s)	99.999999999% (11 9’s)	99.999999999% (11 9’s)	99.999999999% (11 9’s)
Designed for availability	99.99%	99.9%	99.9%	99.5%	99.99%	99.99%
Availability SLA	99.9%	99%	99%	99%	99.9%	99.9%
Availability Zones	≥3	≥3	≥3	1	≥3	≥3
Minimum capacity charge per object	N/A	N/A	128KB	128KB	40KB	40KB
Minimum storage duration charge	N/A	30 days	30 days	30 days	90 days	180 days
Retrieval fee	N/A	N/A	per GB retrieved	per GB retrieved	per GB retrieved	per GB retrieved
First byte latency	milliseconds	milliseconds	milliseconds	milliseconds	select minutes or hours	select hours
Storage type	Object	Object	Object	Object	Object	Object
Lifecycle transitions	Yes	Yes	Yes	Yes	Yes	Yes

Source: AWS official Docs