Architecture

Resources

• System Design Primer
• System Design Cheatsheat

Some Definitions

Load Balancer

A device that serves as a reverse proxy. It distributes network or application traffic across servers. It increases capacity and reliability of applications. Essentially, it evenly distributes requests from users onto the group of application servers.

There are two categories of load balancers:

• Layer 4 - load balancers that work with data in network and transport layer protocols, such as IP, TCP, FTP, UDP.
• Layer 7 - load balancers that distribute HTTP requests and other requests in application layer protocols.
  • Can also distribute requests from HTTP headers, cookies, value of a parameter, and other app specific data.

Algorithms that distribute requests from the two types of load balancers to a particular server include:

• Round robin
• Weighted round robin
• Least connections
• Least response time

Resources:

F5 Glossery