AWS Certified Solutions Architect – Associate (2018)

I have recently cleared the AWS Certified Solutions Architect – Associate (2018).

Based on my preparation and the exam itself, i have compiled some points as per the index below.

Simple Storage Service (S3)

Virtual Private Cloud (VPC)

Elastic Compute Cloud (EC2)

Elastic Block Storage (EBS)

CloudWatch

Relational Database Service (RDS)

DynamoDB

Miscellaneous

AWS Certified Solution Architect – Points to remember (S3)

1. Simple Storage Service.
   
   Durability is same across services.
   Availability reduces marginally with each service.
2. S3 Reduced Redundancy Storage (RRS) will have both availability and Durability at 99.99%.
3. Unlimited Storage. AWS takes care of scaling automatically. This is the only service with almost unlimited storage extended automatically.
4. You can have 100 buckets per account. This is soft limit and can be increased.
5. Cheapest solution for immediate retrival is S3 One Zone IA.
6. S3 Standard, IA and Zingle zone all offer  high durability, high throughput, and low latency.
7. Block based Storage. Means can store only objects  like media files, PDF’s etc.  Cannot run a database or a operating system.
8. Minimum object Size is 0 Bytes for S3 standard and Minumum billable object size for S3 IA and S3 One Zone IA is 128 KB.
9. Size Limit of 5 Terabytes for single object.  The largest object that can be uploaded in a single PUT is 5 gigabytes
10. For big objects it is recommended to use MultiPart upload API.
    Multipart Upload is recommended for files greater than 100 Mb, and is required for files 5 GB or larger.
    
11. Presigned URL’s can be provided to customers/users who dont have access to AWS to upload files to your bucket.
12. HTTP Status code for succesful upload is 200 (Like always).
13. Glacier is used as a data archiving Solution. Cheap storage but costs money for data retreival.
14. S3 maintains the mapping between user defined object names and system defined object names in Glacier. So S3 API or AWS console should be used to retrieve data from Glacier.
15. You can use versioning to preserve, retrieve, and restore every version of every object stored in your Amazon S3 bucket. With versioning, you can easily recover from both unintended user actions and application failures.
16. S3 object access url:
    S3-Region-bucketname.amazonaws.com/object
17. S3 being hosted as static webiste, url will be
    Bucketname-S3-website-Region.amazonaws.com
18. Encryption keys (At rest):Server side encryption:
    S3 – Completely managed by AWS.
    KMS – Also completely managed by AWS but master key is managed by cusotmer.
    C – Completely managed by customer.Client side encryption:
    You have to manage the encryption by yourself completely.