Content Delivery Network (CDN)

A Content Deliver Network (CDN) is a service which caches and delivers content to customers in the fastest way possible. Let's take a closer look at these two aspects of a CDN.

Caching

There's a dichotomy that always plays out when running a successful WordPress site; The greater the success, the more stress is placed on the WordPress site, which in turn reduces performance. To put it more technically, the more customer requests the WordPress site needs to serve, the longer it will take the site to respond to the requests. One antidote which can help cure this ailment is to defer some of the responsibility of responding to requests, to a third-party designed specifically for this purpose. And this is done via caching.

Imagine that you're a clerk at a grocery store, and the store will cease to provide plastic bags, starting next month. You now have the additional responsibility of relaying this information to each customer for the remainder of the month. Of course you can verbally relay the information, but that will get exhausting quickly. A more efficient way is to have a sign to inform the customers. Putting the differences in these forms of communication aside, the sign in this example represents cached information; It is a copy of the original (metaphorically speaking) that is delivered by a third-party, in this case a non-verbal medium.

One of the caveats to using a cache is the need to deal with information which is no longer valid. Using our plastic bag example, let's say that the cloth bags which were supposed to arrive last week are now stuck on a barge due to congestion in a shipping canal; It can happen. The grocery store will now delay the changeover to the following month, which makes the sign invalid. How can this be fixed? As you probably guessed, by replacing the sign with a new one containing the updated information. Likewise, caching systems have a way to invalidate/clear the cache. When this happens, the caching system will request the up-to-date information when customers ask for it. And then, it will cache this updated information and use it to respond to requests, like before.

Content delivery

We argue that caching content is only valuable if the cached content can be delivered to customers faster than the WordPress site can deliver it itself. Otherwise, caching would add unnecessary complexity to a WordPress site. Content Deliver Networks, cache content at different servers, known as Points of Presence. Then, when a user requests the content, it is ideally fetched from the Point of Presence with the lowest latency between itself and the customer. This has two side-effects:

1. Your customer receives the content sooner (faster).
2. Your WordPress site has less work to do, so it can focus more on tasks which Content Delivery Networks can't do.

Our deluxe WordPress hosting solution provides a CDN, giving you that edge of performance you've been looking for. To learn more about our deluxe WordPress hosting plan, click here.