Imagine that you are going to watch a movie, listen to music, visit a virtual exhibition or buy vitamins on the site.
You go to the service, open the page and… And nothing happens.
How long are you willing to wait for a file to download? Statistics say that most users leave a page if it loads for more than 5 seconds.
There is more and more heavy content on the Internet, and users’ demands for page loading speeds are increasing. No one wants to deal with a web service that is slow. According to the surveys, the speed of the Internet resource is one of the main factors for the user.
So what is the solution? CDN (Content Delivery Networks) are used to solve this problem. Let’s find out what it is and how CDN help you load pages quickly.
What is a CDN?
CDN is a geographically distributed group of servers. This entire group works together to deliver Internet content quickly. A CDN helps to cache content at the edge of the network, which improves website performance.
The main idea is to serve website resources from the closest location to the user. They in different countries get the same content from the closest host servers, which greatly speeds up downloads. For example, if a user from Paris requests an image on a website in Sydney, it will be provided from the server closest to Paris.
CDN quickly transfers the assets needed to download Internet content, including HTML pages, javascript files, style sheets, images and videos.
It should be noted that CDN does not host content, nor can it replace web hosting.
Today, most web traffic is served through CDNs, including traffic from sites such as Twitter, Facebook, Netflix, Amazon, and others.
How does CDN work?
In the classic model, the user contacts a web server and it provides the requested content: text, images, music, videos, etc. When using CDN, for sure, we also have a server – Origin, where the original data is stored.
CDN also has a network of caching servers called Point of Presence (PoP) or Edge servers. They don’t duplicate data from Origin, but they do cache static content, which is usually the heaviest and most problematic to deliver.
Thus, the user makes a request to the server expecting to get the HTML page he wants. Server determines the user’s location based on the raw data and automatically redirects the user to the closest server geographically. This operation takes no more than a few seconds. The Origin server usually sends only dynamic content; it’s generated based on the user’s specific request. Static data is sent from the nearest Edge server.
For instance, someone sends a request to a travel agency site: a query to the database takes place, then information about relevant offers received. If users want to read more information about each tour and hotel, or look at pictures, read reviews, they are redirected to the nearest Edge server where all this data is cached. The cache is periodically updated, so users are always provided with up-to-date content.
What are the components of a CDN?
CDN has two key components:
- The first is the edge server. CDN includes many edge servers distributed all over the world. Users everywhere in the world can get high download speeds, no matter where they are: in Poland, Portugal or Kazakhstan. When a user requests content, the edge server that is geographically closest to them delivers it.
- The second is the caching mechanism, aka Original server. This is where the site and its content are stored. If necessary, the caching engine creates a copy of the original data each time content is created or updated, and sends a copy to the edge servers. When a user, everywhere in the world, requests, for example, to view a video, the edge server returns the cached content.
Why businesses use CDN. Benefits.
CDN is important to businesses because it maintains constant access to a website.
By evenly distributing network traffic between servers, CDN prevents hardware failures and traffic bursts that have been caused by heavy user activity or spam attacks.
Today, trouble-free site operation is critical for anyone who has Internet projects.
The main advantage of CDN is that the web site loads faster when it is used. This, in turn, opens up other possibilities.
High speed improves SEO ranking and the site appears faster in search. As a result, the resource becomes more accessible to the user.
CDN shortens the distance between users and website resources. Instead of being connected to any website origin server, CDN allows users to connect to a geographically closer data centre. As a result, less travel time means faster service.
Using CDN is a cost-effective solution for web optimization. By supporting a cached version of content, bandwidth costs are reduced. Smaller file sizes mean faster download times.
CDN secures content, detects malicious links that interfere with the site and blocks them quickly. This helps protect your website from automated bots and spam attacks.
Moreover, CDN offers SSL/TLS encryption that protects data during transmission, prevents distributed denial of service (DDoS) attacks, and provides a high standard of authentication.
Conclusion
I am sure that after reading this article, you have a clear idea of what CDN technology is. You have learned how it works and what its benefits are. In addition, you understand that CDN provides the main request of the user – speed. You can be assured that any content will be delivered quickly, even if you’re looking at a site from another mainland.
What’s more, CDN guarantees an additional level of security between the user and the website. Which, nowadays, is also a key factor.
