Do CloudFlare and quic.cloud really speed up the loading time?

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Cloudflare and quic.cloud: Are you really benefiting from a CDN?

As part of a proof of concept, we tested the cache warmup options of CDN nodes in an extensive test procedure. Although Cloudflare provides over 1.5 million IP addresses, only a fraction of these IP addresses are actually used to cache the content of a page for a CDN. At quic.cloud, it is less than 0.1%, which primarily speaks in favor of CloudFlare. Not only an active cache on a CDN node, but also already cached content is crucial to benefit from the advantages of a CDN. Find out in this post what the goal of this proof of concept was and whether you can achieve real advantages by using a CDN.

What was the Proof-of-Concept about?

The proof of concept in question was primarily about proving whether the cache of a CDN node can be warmed up at CloudFlare, quic.cloud or any other CDN provider. Warming up the cache of a CDN node is essential because only with a warmed up cache is it possible to actually benefit from a CDN. If a warmup is not possible, then the advantages of a CDN are reduced to being able to resolve the IP address of a host more quickly. The time required to resolve an IP address is often considerable, so this factor alone leads to a faster loading time. But it is even faster if the requested content of a URL is already in the cache of a CDN node. However, this requires that a URL must have been called up at least once before. If this is not the case, the respective request is forwarded to the origin server, which corresponds to the basic functionality of every CDN. You only benefit from the advantages of a CDN if the content of a URL is already in the cache. Therefore, the logical conclusion is to find out whether you can achieve a significant advantage by warming up the CDN cache.

Warming up a CDN cache is technically possible, but given that every CDN node has to be connected and the number of nodes is exorbitantly high, attempting to warm up the CDN cache is like trying to count the number of stars in the universe. This means nothing other than that the time required to warm up all CDN nodes rules out any realistic possibility! Or do you really want to warm up the cache of up to 1.5 million nodes?!

What does this mean?

First, the advantages of Cloudflare, quic.cloud or any other CDN provider should be highlighted. The primary advantage is that a CDN can speed up the DNS resolution of a domain. The faster the browser knows which IP address a domain can be reached at, the faster the corresponding host can be contacted. However, this advantage is limited to the first request. With each subsequent page request, a browser already has the information it needs, so the advantages of faster IP address resolution are reduced to the first request for a URL. The aforementioned delivery of content by a CDN is a secondary function that depends on certain and important factors. If the content of a requested URL is not delivered by CloudFlare, quic.cloud or another provider, such a service is not a content delivery network by definition, but simply a proxy.

What conclusions can be drawn from this?

CloudFlare and any other CDN provider offers a clear improvement in the DNS resolution of a domain. This advantage should be used in any case, as DNS resolution contributes significantly to the overall speed of a website.

However, in order to benefit from the advantages of a CDN cache, additional requirements must be met. As already mentioned, the content of the page must be cached on a CDN node to enable accelerated delivery. However, the benefits of the cache depend heavily on the user's location. For example, content cached for a user in Australia is not necessarily available to a user in Singapore. This means that users from different regions may not benefit equally from the cache. This also means that the content of a URL must be cached on every CDN node.

What does this mean for using Cloudflare, quic.coud or any other CDN?

CDNs are generally a good solution for improving the performance of a website. However, the speed advantages promised in advertising are often tied to specific conditions that are regularly NOT met in practice. In order to really benefit from a CDN, a CDN must have the content of a page on EVERY CDN node, i.e. cached. This requirement cannot be implemented in practice, so you should never believe the advertising promises of CDN providers because it is not technically possible!!!

Even if the advantages of a CDN cache are significantly reduced, it is still important to note that a CDN only brings an advantage if the majority of visitors to a website come from another country. Anyone who runs a website where the majority of visitors come from the same country as the server cannot benefit from a CDN. Rather, visitors from the same country/location as the server location are at a disadvantage because a CDN node from the same country is slower. This is not a guess either, but is based on the technical basis of how every CDN works! It is therefore important to carefully consider the use of a CDN! A CDN is therefore not always a good choice.

It is still recommended to use CloudFlare, quic.cloud or any other CDN provider to at least speed up the resolution of the IP address. The accelerated resolution of the IP address alone gives you a significant advantage. However, do not expect to get a significant advantage from a CDN cache, because the conditions for an advantage cannot be achieved in practice! The advertising promise of CloudFlare, quic.cloud or any other CDN provider is put into perspective by the way a CDN and the Internet work! This means that every CDN works as promised, but only if the content of a URL is cached at every CDN node. The emphasis is on "every node". If this condition does not apply and if more users from another country are not accessing your website, you should not use a CDN. Otherwise, users from the same country as your server location will be at a disadvantage, which will lead to disadvantages in the loading time of your website!

Conclusion

It is technically possible to warm up the cache of a CDN node, but it doesn't make sense. Although quic.cloud operates significantly fewer nodes than CloudFlare, the number of CDN nodes is so huge that it would take several days and weeks to warm up the cache of every URL. The promises of every CDN provider are therefore advertising promises that no CDN provider can keep. Therefore, carefully consider whether you really want to use CloudFlare, quic.cloud or another CDN provider, because in case of doubt you and the visitors to a website will be at a disadvantage with whichever CDN you use!