CDN performance
26 Jun 2019

CDN Performance – 4 Reasons Why Your Website May Still Be Slow

CDN performance is vital in today’s digitally-driven, online world. A Content Delivery Network (CDN) is an affordable and proven way to deliver the speed modern web users demand. However, some websites may still not perform at the levels required after an operator has added a CDN to their web application’s delivery architecture. Although it may seem ironic that your site still performs poorly after you have commissioned a CDN service, there are a variety of factors that could impact the speed and performance of a web application. Although utilizing a CDN service will result in web application performance improvements, it should not be the sole factor you rely on to provide your site visitors with a superior user experience. CDNs do not live or operate in a vacuum. They form part of a broader technology ecosystem where a variety of components and factors contribute to the overall performance of a web application.

Adding a CDN to your web application infrastructure will improve performance and reliability. However, the total improvement also depends on factors such as the resources available on your origin server, the network speed from the content source to the final destination, the software architecture of your web application, and the configuration settings of your CDN.

Origin Server Resources

The server that hosts your web application is a vital component in your overall solution architecture. Although a CDN may cache static content that it serves to your site visitors, it still needs to communicate with your origin server regularly to ensure it always presents users with the latest information. In addition to servicing your CDN, the web server that hosts your application, service, or site, also delivers dynamic content that your CDN service may not be able to offer. As modern web apps typically consist of a variety of static assets, dynamic content that is generated in real-time, and interactive functionality such as user authentication, a typical visitor request receives data from your CDN and your origin server simultaneously.

If your web server does not have enough computing resources, visitors accessing your website will receive a poor user experience even if you leverage the services of a CDN. Having enough computing resources is vital in ensuring your web application has the capacity it needs to provide the performance modern Internet users expect. When calculating how much CPU and memory your web platform requires it is also vital that you take the peak demand into account. As traffic to your site varies, you need to ensure your origin server has enough resources to deal with web requests effortlessly during periods of high demand.

Networking Resources Impacting CDN Performance

The speed at which a CDN can pull content from your origin server relies on a variety of technologies. The speed and reliability of the networking resources managing the connectivity between your CDN and origin server is also a vital component in determining the ultimate performance of your web application. Low bandwidth and sub-optimal networking infrastructure can have a significant impact on the user experience of your site visitors. Both your CDN and the user’s browser need to have a fast, reliable connection to your origin server. It is, therefore, vital that the networking resources available are capable of delivering the performance your web application requires.

In today’s digitally-driven world where both society and business rely on technology, a fast, stable network is a critical part of any online service. Bandwidth is a crucial factor as more of today’s modern web applications leverage multimedia solutions such as video streaming to deliver their service to end users. As the network effectively underpins everything that happens in an online environment, you need to ensure the connectivity is capable of delivering the performance expected between your origin server, CDN, and your end users.

Software Architecture

Every web application relies on a variety of software components that together form a solution that delivers the experience and functionality expected by end users. However, not every service or element is developed in-house and hosted on the application’s origin server. Modern web sites rely on various third-party services and libraries that provide the content and functionality driving the visitor experience. However, these dependencies need consistent management and monitoring to ensure the solution delivered meets the performance and functionality expectations of your site visitor.

Most CDNs give you the ability to cache these assets providing the speed and reliability your solution needs. However, should any of these components fail for any reason, the overall performance of your web application can be detrimentally impacted. If your site is not delivering the performance you expect, chances are there may be a third-party service that is failing to load which is affecting your page speed.

CDN Performance and Cache Settings

Multiple cache configuration settings can affect your CDN performance. For example, configuring your cache control headers can help you optimize your CDN and get the best possible performance from your service.  These HTTP headers provide a user’s browser with the ability to cache content in the most efficient manner possible. They also have the added benefit of reducing the amount of bandwidth utilized by the web server resulting in an improved user experience with faster load times.  

Cache-control gives developers the ability to control how each web resource is cached at a granular level. It also provides website operators the capability to set specific controls for third-party services, giving them the flexibility they need to craft a content delivery solution which leverages the advantages of a CDN. However, to get the best possible CDN performance, a careful balance is needed between the content delivered to the user via the CDN cache, and the content provided directly from the originating server.

Understanding the Factors that Influence CDN Performance

Modern web users expect the online applications they interact with to provide the functionality they need in an easy-to-use format and to load as fast as possible. The fact is that 53% of users abandon a site that takes more than three seconds to load. A CDN is a proven way to increase the performance of your web application. However, CDNs alone cannot ensure your site performs at peak efficiency. Resources on your origin server, networking factors, third-party web assets, and cache control settings all contribute to page load speeds. Website operators and application developers must consider all these elements when architecting their online solutions.