What is 20i’s CDN?
The 20i CDN is a powerful content distribution network (or content delivery network) that uses physical, highly optimised servers across the world to cache the content of your websites served from the 20i platform. Cached content of the data is stored at multiple CDN nodes so global customers will connect directly to CDN nodes instead of directly to our local network, resulting in content being served faster and your websites loading quicker.
What are the benefits of a CDN?
Content is actively cached: Every global CDN node actively caches static files. This offers an enhanced and consistent user experience to visitors everywhere - at the same time, page speed is improved and you'll deliver better-performing sites to your users.
Latency is reduced: We have an exclusive number of very well connected datacentres across America & Europe. These exclusive POPs are usually used by transit providers and hence provide the very best latency using the smallest number of POPs. We essentially pay the premium to place hardware directly in “carrier hotels” and neutral datacentres that all traffic from a region will traverse through.
Improved SEO: With 20i’s CDN, you’ll get a Website Acceleration Suite which gives you the tools to help get your Google PageSpeed Score to 100/100. You’ll be able to select the One Click Optimisation section to add the recommended settings which should add the ideal, safe settings to improve website load times. Because page speed is a direct ranking factor for your websites ensuring these options are selected within the 20i control panel can help ensure your websites are optimised for SEO.
You can power-up your websites using 20i's CDN from within your My20i account. See the guide here for more information: How do I use 20i's CDN?
Understanding the 20i CDN
The CDN itself is used to cache static content. By default, the following file types are cached for 60 minutes before being purged automatically.
This type of caching is referred to our Edge Caching as it's cached at our network edge (a.k.a the CDN nodes). This cache can be purged at any time from the Edge Caching section within your control panel, this is accessed via Manage Hosting -> Manage -> Edge Caching. Head down to the Purge Cache section to clear all the cached static content from all CDN nodes.
What is Dynamic Cache?
CDN and StackCache can work complementary to each other. CDN will handle static cache of static file types, whilst StackCache can handle dynamic cache.
For websites on the WordPress Platform (i.e. with StackCache), dynamic content is cached with the default expiry times set.
|Image Cache||1 day|
|CSS Cache||1 day|
You can edit these values from the Edge Caching section or directly from within StackCache in the WordPress admin area. In addition, you can cache any other dynamic content using public Cache-Control and Expires headers via a .htaccess file - however, this is recommended only for advanced users only.
How to check your website is being cached.
The easiest method to check that your site is being cached is to utilise Google Chrome's console to view your websites response HTTP headers. In Google Chrome, follow the steps below to view your websites HTTP headers.
- Using Chrome, visit your website, right-click and select Inspect to open the developer tools.
- Select the Network tab.
- Reload the website and the select any HTTP request from the left panel, the HTTP headers will be displayed in the right panel.
You'll be looking for the
x-cdn-cache-status response to determine if the website has been cached. Please see the table below for the various responses you may see.
|HIT||The websites static content was requested from 20i's CDN.|
|MISS||The websites static content was not found in 20i's CDN and was loaded from the origin server. You will see this on the first load of a website, subsequent reloads should show cache HIT.|
|BYPASS||The origin server instructed the 20i CDN to bypass cache. You will see this if you're within the WordPress Admin - this ensures you'll always see the latest changes you make.|