Welcome to my new series on System Design! This series aims to demystify the concepts of system design, making them accessible and easy to understand. Whether you’re preparing for interviews or looking to build scalable systems, this series will provide you with the foundational knowledge you need.
Why System Design?
System design is crucial for several reasons:
- Career Growth: Many companies, especially tech giants, place a significant emphasis on system design during interviews. Understanding system design can help you land your dream job.
- Scalability: As your user base grows, your system needs to handle increased load without degrading performance. Good system design ensures scalability.
- Reliability: A well-designed system can handle failures gracefully, ensuring high availability and reliability.
Real-World Example:
Consider running a bookstore. Initially, you might handle everything manually – tracking inventory, managing orders, and so on. However, as your business grows, this approach becomes impractical. You need a system to automate these tasks, ensuring that your business can scale efficiently. This is where system design comes in.
The Importance of System Design Interviews
System design interviews are a critical part of the hiring process for many tech roles. They assess your ability to:
- Analyze requirements: Understand the problem and define the scope of the system.
- Design components: Identify key components and their interactions.
- Scale systems: Ensure the system can handle varying loads and data volumes.
- Consider trade-offs: Balance factors like performance, cost, and complexity.
Scaling Concepts: Horizontal vs. Vertical Scaling
Let’s take a closer look at the two main types of scaling through the lens of both a physical bookstore and a web application.
- Horizontal Scaling: Adding more machines or instances to handle increased load.
- Vertical Scaling: Adding more resources (CPU, RAM, disk space) to an existing machine.
Example:
Imagine your bookstore initially runs out of a small shop. As the number of customers grows, you face two options to handle the increased load:
- Vertical Scaling:
- Move to a larger building.
- This improves your capacity but has limits. There’s only so big a single building can get.
- Horizontal Scaling:
- Open new branches in different locations.
- This approach offers better scalability and redundancy, as each branch can serve local customers and share the load.
Now, let’s compare this with a web application.
- Vertical Scaling:
- Upgrade your server with more CPU, RAM, and disk space.
- This can handle more users and requests, but there’s a limit to how much you can upgrade a single server.
- Horizontal Scaling:
- Deploy your application across multiple servers or data centers around the world.
- This allows you to handle more traffic, provides redundancy, and reduces latency by serving users from the nearest location.
Comparison Table:
Aspect | Bookstore Example | Web Application Example |
---|---|---|
Horizontal Scaling | Open multiple branches in various locations | Deploy app to multiple servers/data centers |
Vertical Scaling | Expand to a bigger building | Increase CPU/RAM/Disk on a single server |
Pros of Horizontal | Redundancy, scalable | Redundancy, scalable, reduced latency |
Cons of Horizontal | Management complexity | Load balancing, synchronization |
Pros of Vertical | Simpler to implement | Easier management |
Cons of Vertical | Limited by physical space | Limited by hardware capacity |