CDN (Content Delivery Network) is a geographically distributed network infrastructure created to optimize the delivery and distribution of data to the end user – you and me.
Despite the apparent complexity, in practice, it all works very simply. Imagine a situation: you start the computer, open the browser, then go to a site of interest. So you send a request to the web server, and after a few moments the page will be in front of you – this is the server's response. This is a standard data transfer mechanism, and if there are any problems on the server side, the site simply will not load. But the risk of failure of individual nodes always exists, and CDN technology was developed precisely to prevent such unpleasant situations.
The content delivery (and distribution) network involves the introduction of additional storage and data transfer nodes – these are auxiliary servers that cache part of the content, or even the entire site. That is, the site data is duplicated in several parts of the world – which means that your site will be accessible to visitors even if on the main server some kind of failure will occur. Requests from the visitor will be redirected to the caching server that is closest to the visitor – in addition, this allows you to reduce ping, since traffic will move along the minimum possible route.
CDN network also allows you to seriously reduce the load on the central server. And the more caching servers are connected to your website, the faster and more stable the resource will work. In a nutshell, it increases fault tolerance and security against DoS attacks.
There are 6 key terms that reveal the essence of this technology:
For clarity, you can imagine such a situation – your central server is located in Toronto, Canada, and a resident of any other city somewhere in the world – say, Kyiv, Ukraine is trying to connect to this origin to read the news and find out how their diaspora is doing there in general. The distance from Kyiv to Toronto is approximately 7551 km in a straight line. This is quite a lot, and it should be borne in mind that fiber optic cables do not run in a straight line, so the distance will be even greater. And the ping, respectively, is also huge.
In order for pages to load quickly in such scenarios, a geographically distributed network infrastructure – CDN – is needed. Thanks to the connection of several caching servers in different parts of the world, you will be able to ensure fast loading of the site for all visitors who are within an acceptable radius from the points of presence.
To distribute static content to multiple PoP points, you need:
Content management systems (CMS) have special plugins that are needed to integrate this technology. But you should understand that the points of presence cannot act as classical data stores, they only cache and transmit information from the origin.
Let's highlight the key features:
In the end, this increases the reliability and stability of any resource, so with proper configuration, you can bring the uptime of the site up to 100%. This technology is ideal for online stores, as well as for various streaming services, and software distributors. The same Netflix, YouTube, and Spotify actively use CDN, since there are simply no more worthy alternatives today.
This concludes our material and thanks for your attention. If you have any questions, write to us, our specialists are always in touch.