What is a content delivery network?
Effective page load times are perhaps one of the most vital elements of any website to get right. It’s an incredibly important factor for our customers – especially those seeking reliable web hosting. Whenever possible, you should be looking for ways to shave off even a hundred milliseconds or two from your site's load times, anything to make your pages load faster.
While the difference of a couple of hundred milliseconds might not sound like a major concern, with page load times, even an extra half a second delay on your load times could be enough to convince a user to hit the back button or close their browser altogether. In fact, studies have shown that as little as an extra one-second delay in page loading time can cause a 7% deduction in conversion for e-commerce sites.
The blunt truth is that, if your website takes more than a second or two to load, most people are going to move onto another site. but one way in which you can get around this problem and improve your page load times is with a CDN.
What does CDN stand for?
If you're wondering 'what is a CDN?', it's quite simple. CDN stands for Content Delivery Network. But what is a content delivery network?
In broad terms, a content network is a group of geographically distributed dedicated servers that work together to increase the speed of an internet connection. Put simply, they minimise the physical distance between a user's request and the end server.
To accomplish this, a content delivery network stores a cached version of the content that's being requested in various dedicated server locations around the globe. These locations are called 'points of presence', or PoPs.
These PoPs all hold a cached version of the webpage or site in question. When a request for the content is made, the content network works out where the request is coming from, and then looks for the PoP that is closest geographically to the request's IP. This negates the need to send the request all the way from the UK to Australia, for example. Instead, the request will go to the nearest PoP to access the content, therefore minimising latency and page load times.
Why is a CDN important?
A CDN is important because it helps improve website performance in various ways. Firstly, they offer faster content delivery by storing website content on multiple servers in different locations (PoPs), effectively allowing users to access the content from the server located closest to them. This reduces latency and load times, which ultimately results in a better user experience, improved SEO performance and increased user engagement.
CDNs can also help increase website availability and reliability by reducing the chances of a single server failing and causing website downtime. CDNs can also enhance website security by protecting against distributed denial of service (DDoS) attacks, improving security certificates such as SSL and TLS, and implementing other security improvements.
How does a content network work?
There are two distinct configurations for content delivery network technology: push and pull. The main difference between them is the stage in the request process where the content is served to the content network, meaning you have two options to choose from when setting up your servers.
After setting up a pull content network configuration for a web server hosted in the UK, the very first time a content request is made, the CDN has to figure out which PoP is closest.
Once this is achieved, the PoP then pulls the content from the host server before presenting it to the user. From that point, the cached content is available on the user's nearest PoP to be served locally.
With a push content network, the content is pushed out to the PoPs from the start. A push CDN doesn’t have to wait for the request to be made. The advantage of this is that the first user doesn’t have to wait for the extra step of the content moving from the host server to the local CDN.
However, it's worth noting that the additional delay on a pull content delivery network configuration is only for the first user in that geographic location. All subsequent users in the area are presented with the cached version as normal.
This can actually make pull content networks easier to set up as they require less configuration than initially, and less effort to keep the content up to date. When updates are made on a push content delivery network on the host server, there can be a delay of up to 15 minutes before the content is updated on all of the PoPs in the content network. During this time, a user could either see outdated content or a ‘file not found’ page, causing them to move to a different website.
Who uses CDNs?
CDNs are typically used by content-heavy websites that need to distribute their content with as little latency as possible. Think Netflix, YouTube and similar streaming services that require masses of content storage and strong servers to display content to users. CDNs for these types of content websites ensure smooth playback and reduced buffering – all of which are important features for customers to enjoy their media.
Ecommerce websites are no stranger to CDNs too. Sites like Amazon ensure a seamless shopping experience, particularly when you take the vast array of products they host from sellers across the globe. Social media websites, online gaming platforms and large publications also make use of Content Delivery Networks to distribute content quickly and efficiently, whether through patches, downloadable content (DLCs) and more.
What are the benefits of a Content Delivery Network?
As you can probably tell already, there are tons of benefits to utilising a CDN. Here are just some advantages to using one:
1. Improved website performance
CDNs have servers distributed geographically in various locations worldwide, allowing them to deliver content from a server closest to the user's location. This reduces latency and improves website load times, resulting in a faster and more responsive user experience.
2. Improved user experience
As faster load times and reduced latency provided by CDNs ultimately leads to a better user experience, it can also positively impact the site’s SEO and rankings on search engines. A better overall user experience means users are more likely to stay on a website and engage with its content when it loads quickly, leading to increased user satisfaction and potentially higher conversion rates further down the line.
3. Reduced downtime
With multiple servers worldwide, sites on a CDN are less likely to experience any downtime. So if one server becomes unavailable or experiences issues, content can still be accessed from other servers, enhancing website availability and reducing the risk of downtime.
4. Scalability
CDNs can handle high volumes of traffic and sudden surges in demand more effectively. Think of a popular TV series that’s suddenly got a new season out – users will flock to their favourite streaming service in one go for release day, meaning the site needs to be able to handle the sudden influx in traffic!
By offloading some of the traffic from the origin server to the CDN's distributed servers, these websites can handle increased user traffic without experiencing performance degradation or downtime.
5. Increased security potential
CDNs offer security benefits by providing distributed denial of service (DDoS) mitigation, protecting against malicious attacks, and offering SSL/TLS encryption to secure data transmission between the user and the website.
6. Cost-effective
Using a CDN can reduce hosting costs by vastly reducing the bandwidth required from the original server, and potentially reducing the need for additional server resources. This is particularly useful for content-heavy websites or large ecommerce sites that can be seriously impacted by downtime.
Why use a content delivery network?
The most obvious and important reason to invest in a content delivery network is for the improvement of your page load speeds.
In many cases, a four-second page load time could be decreased to two seconds with cached content on a properly configured content delivery network. This has immediately obvious benefits for metrics such as bounce rates, page views, and conversion rates. Remember, 25% of users will bounce if a page takes more than four seconds to load.
But a content network can also be used for load balancing when a webpage is seeing a surge in traffic. If the content is being pulled from the same PoP location because the surge in traffic is all local, a content delivery network can help manage this by redirecting traffic to another PoP.
Although the latency will increase because there’s more physical distance between the request and PoP, and you'll have to configure the content network to account for load balancing persistence, the page load time will remain lower because there’s less load on both PoPs.
Finally, content delivery network technology also allows for a layer of improved security. Because server requests are effectively coming through a proxy in the form of the PoPs, a content delivery network can be configured to protect your servers from malicious requests like denial-of-service attacks.
The CDN can tell if the request is malicious based on things like its IP address and payload, as well as the frequency and volume of its requests. As the content delivery network is ‘outside’ of the host server, it can block these requests, leaving the host server unaffected.
How does a Content Delivery Network improve website load times?
Besides loading content closer to the user, CDNs also use caching. When a user wants to access content, the CDN will store a cached version of the content on its servers for easy retrieval without having to get it from the origin server. Plus, some CDNs reduce file sizes using things like minification and file compression, because smaller file sizes mean quicker load times.
How does a CDN keep a website always online?
Caching also plays a part here. CDNs cache static versions of website content on other servers. In case the origin server becomes unresponsive or unavailable, these cached versions can be served to site users, ensuring uninterrupted access to the website’s content. This caching mechanism enables the CDN to serve content even when the origin server is experiencing issues.
CDNs also employ data redundancy to enhance website availability. By distributing content across multiple servers located in different geographic regions, CDNs can handle traffic spikes and prevent single points of failure. So if one server goes down or experiences a problem, requests can be automatically routed to other available servers, ensuring that the website remains online.
How to setup a content delivery network
It's possible to construct and self-host your own content delivery network, but in many cases, you can find excellent content network services out there for your own personal use.
Of course, if you plan on self-hosting your own content network, then you'll need more than just a set of dedicated servers. At Fasthosts, we provide excellent web hosting and cloud server options at great prices. Our cloud servers let you choose between servers in the UK, Germany, Spain, and North America, meaning you can have as many PoPs as you need to help balance your user traffic.
But it's not just cloud and server services that we handle. We can also provide domain names, WordPress hosting, and website building for anyone looking to set themselves and their business up online.
If you want even more information about how to improve your internet browsing and website setup, why not take a a look at our detailed articles and guides over on the Fasthosts blog.