Load balancing algorithms (round robin, least connections) in HLD - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the Round Robin load balancing algorithm?

Round Robin distributes incoming requests evenly across all servers in a fixed cyclic order, assigning each new request to the next server in the list.

beginner

How does the Least Connections load balancing algorithm work?

Least Connections sends each new request to the server with the fewest active connections, helping balance load dynamically based on current server usage.

intermediate

Which load balancing algorithm is better for servers with uneven request processing times?

Least Connections is better because it considers current load, sending requests to less busy servers, unlike Round Robin which ignores server load.

intermediate

What is a potential downside of Round Robin load balancing?

Round Robin can overload a slow server because it does not consider server capacity or current load, leading to uneven performance.

intermediate

Why might Least Connections load balancing require more overhead than Round Robin?

Because it must track the number of active connections on each server in real-time, which adds complexity and resource usage.

Which load balancing algorithm assigns requests in a fixed order without considering server load?

A Least Connections

B Weighted Round Robin

C Random

D Round Robin

Round Robin cycles through servers in order, ignoring current load.

Least Connections algorithm directs traffic to which server?

A Server chosen randomly

B Server with the most CPU power

C Server with the fewest active connections

D Server with the highest memory

Least Connections chooses the server with the fewest active connections to balance load.

What is a key advantage of Least Connections over Round Robin?

A Balances load based on current server usage

B Does not require tracking server state

C Always faster response time

D Simpler to implement

Least Connections balances load dynamically by considering active connections.

Which algorithm might cause uneven load if servers have different speeds?

A Round Robin

B Weighted Least Connections

C Least Connections

D IP Hash

Round Robin ignores server speed and load, possibly overloading slower servers.

What extra data does Least Connections need to maintain?

A Server IP addresses

B Number of active connections per server

C Server uptime

D Request size

Least Connections tracks active connections to decide where to send requests.

Explain how Round Robin and Least Connections load balancing algorithms differ in handling incoming requests.

Think about whether the algorithm tracks server usage or not.

Describe scenarios where Least Connections would be preferred over Round Robin for load balancing.

Consider how server load affects performance.