Vertical scaling vs horizontal scaling in HLD - Practice Questions

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding vertical scaling benefits

Which of the following is a primary benefit of vertical scaling in system design?

A It automatically replicates data across different geographic regions.

B It distributes load across multiple machines to increase fault tolerance.

C It allows adding more powerful resources to a single machine to improve performance.

D It reduces the need for load balancers by using multiple servers.

💡 Hint

Think about what happens when you upgrade a single server's CPU or RAM.

Vertical scaling means upgrading the capacity of one machine, such as adding more CPU or memory, to improve performance.

❓ Architecture

intermediate

Choosing horizontal scaling for fault tolerance

In which scenario is horizontal scaling more advantageous than vertical scaling?

A When you want to increase system availability by adding multiple servers.

B When upgrading a single server's CPU is cheaper than buying new servers.

C When the system has low traffic and minimal load.

D When the application requires a single powerful database instance.

💡 Hint

Consider how spreading load across machines affects uptime.

Horizontal scaling adds more machines to share the load, improving fault tolerance and availability.

❓ scaling

advanced

Scaling tradeoffs in database systems

What is a common tradeoff when choosing horizontal scaling over vertical scaling for a database system?

A Horizontal scaling can increase complexity due to data consistency challenges.

B Vertical scaling makes it easier to distribute data across regions.

C Vertical scaling requires more network bandwidth than horizontal scaling.

D Horizontal scaling always reduces latency compared to vertical scaling.

💡 Hint

Think about how data is managed across multiple machines.

Horizontal scaling often introduces complexity in keeping data consistent across servers.

❓ estimation

advanced

Estimating capacity with horizontal scaling

If a single server can handle 1000 requests per second, how many servers are needed to handle 10,000 requests per second using horizontal scaling?

A 100 servers to ensure redundancy

B 1 server upgraded 10 times

C 5 servers with double capacity each

D 10 servers

💡 Hint

Divide total requests by capacity per server.

To handle 10,000 requests with servers each handling 1,000, you need 10 servers.

❓ tradeoff

expert

Choosing scaling strategy for a global web application

For a global web application requiring low latency worldwide and high availability, which scaling approach is best?

A Vertical scaling by upgrading a central server to the highest capacity.

B Horizontal scaling with distributed servers across regions and load balancing.

C Vertical scaling combined with a single regional data center.

D No scaling, relying on caching only.

💡 Hint

Consider geographic distribution and fault tolerance.

Distributing servers globally with horizontal scaling reduces latency and improves availability.