[AWS - DA] S3

Overview

Object values are the content of body:
- Max Object Size 5TB (5000GB)
- If uploading more than 5GB, must use "multi-part upload"
Metadata (list of text key /value pairs)
Tags (to to 10)
Version ID

It is enabled at bucket level
Same key overwrite willincrement the version : 1,2,3...
It is best practice to version your buckets
Any file that is not versioned prior to enabling versioning will have version "null"
Suspending versioning does not delete the previous versions

User based
- IAM polices - which API calls should be allowed for a specific user from IAM console
Resource based
- Bucket Policies - bucket wide rules from the S3 console - allows cross account
- Object Access Control (ACL) - finer grain
- Bucket Access Control List (ACL) - less common
The user IAM permissions allow it OR the resource policy ALLOWS it
AND there's no explicit DENY
Networking
- Supports VPC Endpoints (for instances in VPC without www internet)
Logging and Audit
- S3 Access Logs can be stored in other s3 bucket
- API calls can be logged in AWS CloudTrail
User security
- MFA Delete: MFA can be required in versioned bucekts to delete objects
- Pre-singed URLs: URLs that are valid only for a limited time

CRR - Use case: compliance, lower latency access, replication across acounts
SRR - Use case: log aggregation, live replication between production and test accounts

After activating, only new objects are replicated
For DELETE operations:
- Can Replicate delete markers from source to target (optional setting)
- Deletions with a version ID are not replicated (to avoid mailcious deletes)
There is no "chaining" of replication
- If bucket 1 has replication into bucket 2, which has replication into bucket 3
- Then objects create in bucket 1 are not replicated to bucket 3

Strong consistency as 12th 2020
After a:
- successful write of a new object (new PUT)
- or an overwrite or delete of an existing object (overwrite PUT or DELETE)
...any:
- subsequent read request immediately receives the latest version of the object
- subsequent list request immediately reflects changes
Available at no additional cost, without any performance impact

MFA forces user to gerate a code on a device before doing important operations on S3
To use MFA-DELETE, enable Versioning on the S3 bucket
Only the bucket onwer (root account) can enable/disable MFA-DELETE
MFA-DELETE currently can only be enabled using CLI
You will need MFA to
- permantly delete an object version
- suspend versioning on the bucket
You won't need MFA for
- enabling versioning
- listing deleted version

Amazon Glacier - 3 retrieval options

Amazon Glacier Deep Archive - for long term storage - cheaper:

Increase transfer speed by transferring file to an AWS edge location which will forward the data to S3 ucket in the target region
Compatible with multi-part uplaod