Differences between horizontal scaling and vertical scaling?

Vertical scaling means scaling the compute power such as CPU, RAM to your existing machine while horizontal scaling means adding more machines to your server or database. Horizontal scaling means increasing the number of nodes, and distributing the tasks among different nodes.

In the context of Power BI interview questions, understanding the differences between horizontal scaling and vertical scaling is crucial. Here’s how you can explain it:

  1. Vertical Scaling (Scale-Up):
    • Vertical scaling involves increasing the capacity of a single resource in a system.
    • In Power BI, this could mean upgrading the hardware of a single server or increasing the capacity of a single node in a server cluster.
    • It typically involves adding more CPU, memory, or storage to an existing server.
    • Vertical scaling has its limitations, as there’s a maximum limit to how much you can upgrade a single resource.
  2. Horizontal Scaling (Scale-Out):
    • Horizontal scaling involves adding more resources to distribute the workload across multiple machines or servers.
    • In Power BI, this could involve adding more nodes to a server cluster or deploying additional servers.
    • It allows for better scalability as the workload can be distributed across multiple resources, potentially increasing overall performance and capacity.
    • Horizontal scaling is often achieved through technologies like load balancing and distributed computing.

Key Differences:

  • Scalability: Vertical scaling is limited by the maximum capacity of a single resource, while horizontal scaling can theoretically scale infinitely by adding more resources.
  • Cost: Vertical scaling can be more expensive, as high-end hardware upgrades tend to be costly. Horizontal scaling, on the other hand, can be more cost-effective as it involves adding commodity hardware.
  • Complexity: Horizontal scaling may introduce more complexity in terms of managing multiple nodes or servers, whereas vertical scaling may be simpler since it involves upgrading a single resource.
  • Availability: Horizontal scaling can potentially offer better availability since it distributes the workload across multiple servers, reducing the impact of a single point of failure.

In the context of Power BI, understanding these concepts is important for optimizing performance and scalability of your Power BI solutions, especially when dealing with large datasets or high user loads.