System Design

What is the disadvantage of Horizontal Scaling? What is often required in order to perform Horizontal Scaling?

Difficulty: unrated

Source: bregman-arie/devops-exercises by Arie Bregman

Answer

A load balancer. You can add more resources, but if you would like them to be part of the process, you have to serve them the requests/responses. Also, data inconsistency is a concern with horizontal scaling.