In this article, you will learn:

• How the WEDOS Global CDN cache works
• How to set up CDN cache
• Common issues
• Frequently asked questions

WEDOS Global caches content within its global network of proxy servers, which the web server returns with certain HTTP return codes, such as 200 (OK), 302 (Found), 304 (Not Modified), 307 (Temporary Redirect), and 404 (Not Found). It offers two configuration options:

• CDN static content caching doesn’t distinguish between cached file extensions and may cache dynamically generated pages (e.g. .php) if the server returns them with one of the listed codes and they are not specifically excluded from caching. This is the default setting for caching servers.
• CDN file caching focuses on caching specific file types based on their extensions. This mode is available in the Advanced plan and above, and allows you to customize the list of cached extensions.

The default CDN static content caching mode is more comprehensive and caches all content with the appropriate return codes. It is suitable for websites with a high volume of static content that want to maximize their performance. Website administrators who require precise control over the cached files, for example due to frequent content updates or specific performance requirements, will prefer to use CDN file caching.

The caching server keeps files in memory for 3 to 60 seconds, depending on the chosen plan. After this time, it asks the source server whether the content is still up-to-date. This short cache retention period is sufficient even for websites where the content is important, such as discussion forums.

To set up CDN cache, follow these steps:

1. Log into the WEDOS Global administration panel.
2. Select a domain (or template) to set up.
3. In the left menu, click CDN Cache.

The available settings depend on the plan used:

• Start and above: Enable/disable, purge cache
• Advanced and above: Mode

If content caching is causing problems that cannot be fixed in the code, you can turn it off at any time and turn it back on later.

If only the current cache status is problematic (for example, content that is not updated for some reason), simply purge it using the corresponding button.

If you are using the Advanced plan and higher, you can choose a caching mode. For a detailed description of the features of the available modes, see the WEDOS Global CDN Cache chapter.

You can find the mode switch in the CDN Cache Mode section. There are no additional settings available for the CDN static content caching mode, selecting the CDN file caching mode will open an interface for managing cached file extensions. This will allow you to:

• Add/delete a file extension or group.
• Enable/disable caching of the selected extension or group.

The default list of cached extensions is: .png, .css, .jpg, .jpeg, .ico, .js, .webp, .gif, .svg, .woff2.

Common issues with WEDOS Global CDN cache include:

• Cached content doesn’t update
• Disabling the cache doesn’t work

Issue: Out-of-date content (such as an error message) remains in the cache.

Solution: Purge the cache using the corresponding button in the administration panel.

Issue: The cache is disabled, but the problem on the website persists.

Cause: The content may be cached elsewhere.

Solution: Make sure to clear all cached content. In the case of a browser, the keyboard shortcut Ctrl+Shift+R usually helps, and also check the cache settings in your content management system.

Question: If my content is cached using a WordPress plugin, should I still use WEDOS Global CDN?
Answer: WordPress caches content only on the server where the website is located. WEDOS Global caches content on special servers located around the world, ensuring faster response – the content is physically closer and does not burden the web server, which therefore has more free resources to generate it.

The WEDOS Global WordPress plugin offers both local and CDN caching.