An Introduction to HTTP Caching in Ruby On Rails
It's 2024, and the HyperText Transfer Protocol (HTTP) is 35 years old. The fact that the vast majority of web traffic still relies on this simple, stateless form of communication is a marvel in itself.
A first set of content retrieval optimizations were added to the protocol when v1.0 was published in 1996. These include the infamous caching instructions (aka headers) that the client and server use to negotiate whether content needs refreshing.
28 years later, many web developers still avoid using it like the plague. A great deal of traffic and server load (and thus, latency) can be avoided, though, by using the built-in caching mechanism of the web. Not only does this result in a greatly improved user experience, it can also be a powerful lever to trim down your server bill. In this post, we'll take a look at:
Let's assume we have a shared cache server in place that stores responses from our app server for reuse. Later, a client issues a request to our app server. The stored response in our cache is now in one of two states:
