Why do we use caches?
To place content closer to end users
What 2 places do you place caches?
- External - to end users like images, videos, static content
- Internal - in front of a database for reads
What is Cloudfront?
Content delivery network for external caching for placing resources globally using AWS Edge Location
What are 4 caching services?
- CloudFront
- ElastiCache
- DAX
- Global Accelerator
Why use CloudFront? 4 things
- Enables default HTTPS for your content
- Secure connection for S3 static websites
- Can be used for non-AWS (on-prem) applications
- Can force an expiration on cached content
What is a major restrictions on CloudFront?
- You can’t really block specific countries, you should use WAF instead, as restriction is by general geographies
- You can’t pick specific Edge Locations for caching, its either all locations or specific geographies
Can you use Presigned URLS or Cookies?
Yes you can give temporary access content using presigned urls/cookies with CloudFront
What are the 2 SSL options with CloudFront?
You can use a default ssl certificate or give a custom ssl certificate with your own domain name to be used with CloudFront
What is ElastiCache?
AWS Managed caching service using Redis or Memcached
Can Redis be used as a database?
Yes Redis can be a standalone NOSQL database as well as a caching solution
What are the 4 difference between Redis and Memcached?
- Redis provides more complex caching solution vs simpler caching
- Redis can be standalone db vs. just a caching solution
- Redis has failover and MultiAZ vs none of these
- Redis has backups vs no backups
What is DAX?
DynamoDB Accelerator, in memory caching for milliseconds down to microseconds
What location is DAX located?
- Lives in a VPC you choose
What are 2 benefits of DAX other than the reduced latency?
- It is HA
2. Has lots of configurations for you
WHat is GLobal Accelerator?
Uses AWS global network (Edge locations) to help increase performance
How do you solve the issues of IP Caching by end users?
You can uses Global Accelerator
How does GLobal Accelerator solve IP Caching?
It gives 2 static ips to end users, and Global Accelerator sits between end users and the ELB
What are 3 benefits of Global Accelerator?
- Gives 2 static ip’s that mask any architecture changes behind
- Speeds up network traffic due to Edge Locations AWS backbone
- Weighted pools with different endpoints to provide failover or A/B testing
Do you have to use the 2 static IP’s from AWs? for Global Accelerator
No, you can bring your own custom ip’s
IF you see in memory databse on exam what should you pick? favor which of them?
- Redis and DyanmoDB
2. Favor DynamoDB
Does DAX have backups?
No it does not, it is not a database solution
