Most businesses now have clients from every corner of the world. Back in the day, if you had an online store, you would just host it on a dedicated server in a specific data center and focus only on clients located geographically close to that data center. If you decide to use such an option today and you have customers and partners from all over the world, it is likely that some of them will have problems loading the specific resources fast enough compared to your competitors. Such high response times might cause you a lot of problems and even revenue loss.

Handling a huge traffic volume as well as minimizing and localizing downtimes to only certain parts of the world (CDN nodes) would make you consider using CDN instead of dedicated servers hosted in a single location. Hybrid networks also exist where people use both CDN and dedicated servers for different parts of the content. 

So, what is a CDN? CDN is short for Content Delivery Network or Content Distribution Network. Firstsiteguide.com have posted a very comprehensive gudie about CDNs and how to find the best CDNs for your website.

The CDN nodes are located in different data hosting centers around the world with multiple backbone connections and different ISPs in order to make the whole content distribution network much more stable and downtime proof.

Most of the Internet content which is served today, actually comes from CDNs. CDNs are used to serve static and dynamic websites but its main advantages can be utilized when serving video and audio content and Internet television. Most social networks and big e-commerce portals also use mostly CDNs due to the high number of simultaneous connections they get every second.

When using a CDN, your content will be copied to multiple servers in different geographical locations. A large CDN will consist of hundreds and even thousands of different servers, all of which have copies of your content.  Your applications will not experience problems during periods of maximum load and your system will be able to deal with a huge number of simultaneous requests.

One of the best features of a CDN is that it allows a fail-safe degradation of the network in cases of Internet problems or attacks. Even if your site is under a massive DDoS attack, at least some of your clients will be able to get the correct content from the CDN nodes which are not affected. Since you have basically the same copies of that data on many servers, it can also serve as a great backup tool in case something happens to a specific CDN node and you lose data. Customization is also possible where specific content will only be displayed for specific geographical locations.

When clients request content from a CDN, they are automatically diverted to the server which is closer to them. This way the content can be delivered much faster and the routes between the machines are optimized.

The best option to monitor a CDN will be to use as many different monitoring locations as you can. We are constantly expanding our network and right now we have 40 different monitoring locations. Depending on your CDN configuration, the locations situated in different countries or continents will most likely reach different nodes of your content distribution network. You can use our free test tools and do HostName tests to find out exactly which node each of our servers is hitting. If we start detecting problems only from some of the locations, this will indicate that only certain nodes are not working correctly and you should consider contacting out your CDN provider. Since using all of our 40 locations might come out too expensive, you should at least consider using several of them.

If you are experiencing problems only for a specific geographical region, you might want to monitor a specific node (by using its IP address and not the domain name) and/or using only the monitoring locations close to the specific place.

You can use most of our monitoring levels to monitor a CDN but the performance and full-page levels are the most widely used ones. You can also consider using our application and transaction levels of monitoring if you have an e-commerce site for example and you want to check that all applications are working fine as well.