S3

Question 1

How can you store multiple editions of a file?

Answer 1

Through bucket versioning.

Question 2

What kinds of encryption do exist for s3?

Answer 2

-SSE-S3
-SSE-KMS
SSE-C

Question 3

How does SSe-S3 work?

Answer 3

User uploads object to s3 and provides a header for enabling encryption. Key is managed by s3.

Question 4

How does SSE-KMS work?

Answer 4

Object is encrypted by a master key managed by kms

Question 5

How does SSE-C work?

Answer 5

Object is encrypted by a cloent provided key.

Question 6

How can you manage file access permissions in s3?

Answer 6

• user based with am

- resource based through access control lists

Question 7

How does CORS work?

Answer 7

1. The browser calls the origin url.
2. The original content requires a foreign resource
3. The browser sends a preflight request to the foreign server with the origin inside the header
4. The foreign server answers with the allowed http methods for the denoted origin
5. The browser requests the resource

Question 8

How consistent is s3?

Answer 8

strongly consistent as of december 2020

Question 9

How can you prevent unauthorised or accidential delete of objects?

Answer 9

through multi factor authentication (mfa)

Question 10

How can you enforce encryption of objects?

Answer 10

use bucket policy and deny any put object call without encryption header

Question 11

How can you monitor access to an s3 bucket

Answer 11

through access logs made to another s3 bucket

Question 12

How can you introduce fault tolerance to an s3 bucket?

Answer 12

Through async cross region or same region replication.

Question 13

You want a premium user to download a file from your bucket. How can you temporarily grant them access to the object?

Answer 13

Through presigned urls.

Question 14

What storage classes are available in s3?

Answer 14

• Standard General Purpose (11 9 durability, 99.99 availability)
• Standard Infrequent access (9 9 durability, 99.9 availability)
• One Zone Infrequent access (data only in one az, 99.5 availability, 9 9 durability)
• Intelligent tiering (9 9 durability 99.99 availability, moves data between general and infrequent automatically, is multi az)

Question 15

How can you move objects automatically between s3 classes?

Answer 15

Through lifecycle rules.

Question 16

How can you determine time periods for lifecycle rules?

Answer 16

Through storage class analysis

Question 17

How can you react to events in s3?

Answer 17

By publishing notifications on events in s3 (read, write, update, …)

Question 18

How can you perform analysis on data in s3 directly?

Answer 18

using athena

Question 19

How can you prevent object changes for compliance reasons?

Answer 19

By enabling object lock in compliance mode (a protected object version can’t be overwritten or deleted by any user, including the root user in your AWS account. When an object is locked in compliance mode, its retention mode can’t be changed, and its retention period can’t be shortened)