Building Scalable Apps with Redis and Node.js

Scalability

We have automated the rolling out of our code to servers in the cloud, but how is this scalable? The first thing we take a look at is a diagram of how our application looks:

The front public-facing address of our site will be the server that is running HAProxy. In this setup, we will only want one server running HAProxy, and if it is production, this site should have a static IP and a public DNS record. HAProxy is very efficient at load balancing, and one of them can handle a lot of traffic. Eventually, we can run two behind a balanced DNS record, for example, but this is out the scope of this book.

HAProxy will then send the requests ...