Understanding Scalability in System Design
Scalability refers to a system's ability to handle increased load without compromising performance. In system design, it's crucial for ensuring reliability as user demand grows. This lesson builds on the system design process by focusing on how to scale systems effectively.
There are two primary types of scalability:
- Vertical Scalability (Scaling Up): Involves adding more resources to an existing machine, such as increasing CPU, RAM, or storage. This is straightforward but has limits based on hardware constraints.
- Horizontal Scalability (Scaling Out): Involves distributing load across multiple machines or nodes, often using load balancers. This allows for theoretically unlimited growth but requires more complex architecture.
For example, a simple web server might start with vertical scaling by upgrading server hardware, but as traffic surges, horizontal scaling with cloud instances becomes necessary.