Overview of Load Balancing
In the DNS overview, you learned what happens when one client tries to connect to a website. amazon.com is a very popular website, however, and at any one time, it might have to handle thousands, if not hundreds of thousands, of requests. A single server cannot handle that many requests, and so large, busy websites are often served on multiple servers. To accomplish this, you need a way to make sure the requests are spread evenly across the servers that serve the website. This is where load balancing comes in.
A load balancer sits in front of your servers and routes requests across the servers that it manages according to its configuration. It ensures that requests are only routed to healthy servers and that those healthy servers are not overloaded. As such, load balancers are key items of infrastructure to ensure high availability, redundancy, and flexibility.
High Availability and Redundancy
A lot of the design decisions you make in the cloud come...
