Caching

Question 1

Is CloudFront an Internal or External Cache

Answer 1

External

Question 2

Is Elasticache an Internal or External Cache

Answer 2

Internal

Question 3

Is DAX an Internal or External Cache

Answer 3

Internal

Question 4

Is Global Accelerator an Internal or External Cache

Answer 4

External

Question 5

What is CloudFront?

Answer 5

• Its AWS’s CDN (Content Delivery Network)
• Allows is to push content to Edge Location

Question 6

How is CloudFront related to edge locations?

Answer 6

CloudFront allows us to push content into Edge Locations

Question 7

Why Consider using CloudFront?

Answer 7

• Defaults to HTTPS
• Allows the use of certificates
• Allows you to put a secure connection on S3 static websites
• Can use it to front non AWS applications
• Can force expiration of content before TTL

Question 8

Can you pick specific Countries when using Cloud Front? Edge Locations? What can you pick?

Answer 8

Cannot pick countries or edge locaitons. You pick general regions

Question 9

Why might you use signed URLs or signed cookies?

Answer 9

To restrict access. These are basically temporary access points

Question 10

How can you add additional security to CloudFront?

Answer 10

You can enable WAF

Question 11

How do you block connections using CloudFront?

Answer 11

Best way is using Web Application firewall (WAF)

Question 12

What is ElastiCache?

Answer 12

Its a managed version of Memcached and Redis. it allows you to spin up these two tools easily.

Question 13

Why might you use Memcached?

Answer 13

• Simple database cache ONLY.
• No typical DB features.

Question 14

Why might you use Redis?

Answer 14

• Supported as a caching solution
• functions as a standalone database (NoSQL)
• can failover and supports multi-AZ
• supports backups
• Is a good option if DynamoDB isn’t available and you need NOSQL

Question 15

Can Memcached exist on its own as a database?

Answer 15

No.

Question 16

What is DAX?

Answer 16

• Dynamo DB Accelerator
• In-Memory Cache
• Go from milliseconds to microseconds
• Lives in a VPC
• Highly available

Question 17

Can DAX be used for anything else other than DynamoDB?

Answer 17

No.

Question 18

What is Global Accelerator?

Answer 18

Increases application performance and helps deal with IP caching

Question 19

Describe how Global Accelerator helps an application

Answer 19

• Global accelerator sits between users and your load balancer and offers two IPs that never change, even if the ELB does.

Question 20

I say IP Caching you say…

Answer 20

Global Accelerator!

Question 21

How do you secure access to an Elasticache Redis cluster?

Answer 21

Use the AUTH commant

Question 22

What are CloudFront Origin Groups for origin failover used for

Answer 22

Designates a primary and secondary origin when the primary returns specific HTTP failures

Question 23

What methods could you use to increase your cache hit ratio when using CloudFront?

Answer 23

1. Increase the TTL longer could mean stale images
2. Configure the distribution to forward requests that will return unique objects
3. Remove the accept encoding header when compression isn’t needed
4. Serve media content using HTTP