AWS — High Availability and scalability
Scalability: It means that the application/system handle greater loads by adapting.
There are two types of scalability:
- Verticle scalability
- Horizontal scalability(= elasticity)
- It means increasing the size of the instance.
- For example, your application runs on a t2.micro
- Scaling the application vertically means running it on t2.large
- Vertically scalability is very common for non distributed systems such as databases.
- RDS, ElastiCache are services that can scale vertically.
- It means increasing the number of instances.
- It implies distributed system such as a web application.
- It usually goes hand in hand with horizontal scaling.
- It means running your application in at least 2 data centres (==availability zones)
- The goal of high availability is to survive a data centre loss.
- It can be passive or active.
This article content is taken from Stephane Maarek(Udemy Instructor).
Happy to Help :)