On this Page

Introduction to Amazon S3

S3 is an acronym for Simple Storage Service. It’s a service that allows us to store unlimited amount of data on AWS without managing the infrastructure.

We have buckets which are containers for objects .Objects in turn are files and meta data describing the files.

We can upload files, open, download and delete files from an S3 bucket. We can also manage access to the files via ACLSs (legacy) and Bucket Policies (recommended).

S3 storage on objects are determined by the storage class of the object. By default, new objects are placed in the S3 Standard class if you do not specify a storage class during object creation.The other classes are Amazon S3 Standard (S3 Standard),Amazon S3 Intelligent-Tiering (S3 Intelligent-Tiering),Amazon S3 Standard-Infrequent Access (S3 Standard-IA),Amazon S3 One Zone-Infrequent Access (S3 One Zone-IA),Amazon S3 Glacier Instant Retrieval, Amazon S3 Glacier Flexible Retrieval (Formerly S3 Glacier),Amazon S3 Glacier Deep Archive.

Object versioning- used to maintain versions/updated copies of objects when newer copies of the object is uploaded to the bucket. This is also helpful when deleting objects as only the most recent copy/version is deleted. Older versions are maintained.

Data in S3 is replicated across at least 3 Availability Zones for high availability.

Data in S3 can be duplicated in another region through Cross Region Replication (CRR) for durability. To use CRR,versioning must be turned on in the source bucket and destination buckets.

S3 offers Storage Lifecycle Management to move your objects across various storage tiers/classes to save you storage costs. For example if an object is no longer frequently accessed after a few days,

we can move it from the S3 Standard to Amazon S3 One Zone-Infrequent Access (S3 One Zone-IA) after 30 days of creation.


S3 Lifecycle configuration rules are of 2 types;

1.Transition actions –these rules define transition of objects from one storage class to another after a given time period .e.g. moving an object from S3 Standard to One Zone-Infrequent Access (S3 One Zone-IA) after 30 days.

2.Expiration actions-these rules define when the objects are to expire.On expiration,S3               will delete the objects.When an object reaches the expiration date,its queued for deletion.The deletion is asynchronous and there might be a delay/lag between when an object expires and when S3 actually removes the item.However,there are no extra storage charges for this delay.

S3 is a very crucial  Amazon service and integrated with many other if not almost all S3 services like Lambda,CloudFront,Kinesis,EC2,e.t.c the list is long.

S3 is a global service in that it is available in all AWS regions.

About the Author - John Kyalo Mbindyo(Bsc Computer Science) is a Senior Application Developer currently working at NCBA Bank Group,Nairobi- Kenya.He is passionate about making programming tutorials and sharing his knowledge with other software engineers across the globe. You can learn more about him and follow him on  Github.