How to Decide Whether Your Site Needs a CDN

While content delivery networks (CDNs) have been around a long time now, most of us aren't totally clear on what they do, how they work, or whether we need one for our site or business.

What is a CDN?

There is a lot of confusion over what a CDN does because they have multiple important uses. Some use them primarily to reduce page load times which is an increasingly important factor in search engine rankings. But increased speed is not the only primary reason to use a CDN. Other important uses are:

• Load balancing of high traffic
• Enhanced security through blocking scrapers, spammers, fake Google crawlers and other bad bots
• Possibly reducing bandwidth consumption (depending on your traffic)
• Protection from DDoS attacks

All of us use CDNs everyday. Over half of all internet traffic is already being routed through CDNs. So the question is, should you be using one? To better understand when a CDN is necessary, refer to the The Essential CDN Guide published by Incapsula Imperva for more details. Let's discuss some reasons you might want to use a CDN.

What Sites Most Need a CDN?

Does your site have high traffic? Do your visitors come from all over the world? Would having your site go down result in major financial losses? If any of these are true for you, seriously consider using a CDN. If it is essential for your site to never go down, you need your entire site to live on at least two separate servers in different locations. Your CDN can automatically switch all traffic from the failing server to a backup server. The ability to do this is known as Failover service. Online gaming and multi-player role-playing sites can use CDNs to reduce latency and speed up play. The faster your games run, the longer your users will continue to play. Speed is also a factor in how well your site ranks in Google. Improving site load times is the #1 reason cited for looking into using a CDN. By caching your content on a server closer to your visitor, pages will load faster. It is even possible to leverage your CDN to cache "uncacheable" content.

When a CDN May Not Be Necessary

The number one reason you may not want to use a CDN is when you have many very large video files that get very little traffic. Paying for the bandwidth to download each video to each server location even when viewers only watch a few seconds can result in having your bandwidth consumption go up instead of down. This can make using a CDN very expensive - especially for people with long videos. If your website is for a local business and almost all of your visitors are located near your geographic area, you won't see much benefit as far as page load times go. The less traffic you have, the less need you have for a CDN for speed purposes. You may still want one for security, however.

Different Types of CDNs

Be aware that there are multiple types of CDNs. Each of them has pros and cons. Understanding the strengths and weaknesses of each type before making your decision is important. Newer CDNs are not just static or dynamic - they are multi-purpose. Some are stronger regarding security while others focus primarily on page load speed. Many of the factors involved in choosing the best CDN for your site are highly technical, so you may wish to consult an expert before deciding.

CDNs Are Easy to Install

If you had to configure your own servers and CDNs it would be quite complex and time-consuming. Fortunately, using existing CDNs is fairly simple. In most cases you simply repoint your DNS servers from the server where your site is hosted to the IPs for the CDN company's servers. It isn't really necessary to understand all the technology behind a CDN; you can leave that to the experts and just enjoy the protection, page load speed, reliability, and security using a CDN can bring.