What is the difference between scalability and elasticity?

Question

I\'ve heard many people using both terms interchangeably. However, in my opinion there is difference between them:

SCALABILITY - ability of a softwa

Answer 1

In terms of AWS:

Scalability refers to the ability for your resources to increase or decrease in size or quantity.

There's a lot of infrastructures involved to make something like this happen, so it's no easy task.

Many of the services in AWS are scalable by default, which is one of the reasons that AWS is so successful.

Scalability is pretty simple to define, which is why some of the aspects of elasticity are often attributed to it.

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Elasticity is the ability for your resources to scale in response to stated criteria, often CloudWatch rules.

This is what happens when a load balancer adds instances whenever a web application gets a lot of traffic.

Scalability is required for elasticity, but not the other way around.

Not all AWS services support elasticity, and even those that do often need to be configured in a certain way.

It might seem redundant, but the services in AWS that start with "Elastic" often support elasticity.

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In resume, Scalability gives you the ability to increase or decrease your resources, and elasticity lets those operations happen automatically according to configured rules.