Content Delivery Network (CDN) is a concept where a group of servers are used at multiple locations across the globe, each having the same content for delivery. As a result, the content from the nearest server (CDN node) is delivered to the end user. It helps fast, secure and reliable delivery of the content and also reduces the load on the web servers.
Modern web and mobile applications are having lot of features and dynamism, which are compelling for the end users. But the performance and availability are critical factors for their successful deployment. Here, CDN plays an important role to meet the end user requirements. So the testing of the CDN platform is a must before the application goes live.
Now, let us have a look at some of the best ways to test the CDN set up.
- Use existing website name (URL) as CNAME
Before starting the test, the owner of the website must delete the existing DNS record for the existing website. The first step is to make a CNAME to the URL given by the CDN provider. Here in this method, the existing website name (URL) is used as the CNAME for the new URL given by the CDN provider. After this flush clear browser cache and test the website if everything is working fine or not. It should work fine as per as the DNS changes are correctly propagated to the ISP. The IP address can also be checked by using ping command. This is not an efficient method, but it is a quick test to get the job done.
- Map IP in the host file
In this method, the IP of the URL provided by the CDN provider is mapped with the existing URL (website) in the host file. After this, the browser and DNS cache is cleared. Now the site is tested to check its performance. This is more efficient way compared to the previous one.
- By using HOST header information
In this approach the server information and the host header information is manipulated to test the new CDN setup. In this process, first the client gets the IP address of the URL provided by the CDN provider. After this the client creates a HTTP connection with the IP returned in the previous step. Then the client requests the server for the desired file and includes the original URL (which was used before) in the request header. The server uses the host header information to find the virtual mapping zone. Now, you are connected to the CDN provided URL to get the response. This is one of the best ways to test CDN set up.
There are various CDN providers available in the market for implementing content delivery network. CDN is now widely used for better performance and availability of the web content. It is like a distributed content delivery system.