Vertical and Horizontal Scaling

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Arjit Sharma
01 Min

Scaling is how businesses handle increased demand on their systems. Whether you’re running a website, an app, or a service, scaling ensures your system can handle more users or data without crashing.

Vertical Scaling (Scaling Up)

vertical-scaling

Vertical scaling means making a single machine more powerful, adding more RAM, faster procesor, bigger hard-drive.

Advantage -

  • Easy to implement.
  • No need to change your application.

Disadvantage -

  • Limited by the maximum capacity of the hardware.
  • Can get expensive as you scale up.

Horizontal Scaling (Scaling Out)

horizontal-scaling

Horizontal scaling means adding more machines to share the workload. Instead of upgrading one server, you add more servers and distribute the traffic between them.

Advantage -

  • No limit to how much you can scale.
  • Reduces the risk of a single point of failure.

Disadvantage -

  • More complex to set up.
  • Requires changes to your application (e.g., making it stateless).

Case Study

Initially, Netflix relied on vertical scaling by upgrading its on-premises servers to handle growing traffic. However, this approach proved costly and limited, especially during a major database failure in 2008. To overcome these challenges, Netflix transitioned to horizontal scaling by migrating to AWS.

Over time, they further optimized their system with a microservices architecture and their own CDN, Open Connect, showcasing how horizontal scaling can support massive global growth compared to the constraints of vertical scaling.

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