Web Hosting - WordPress - Content Delivery Network (CDN) with W3 Total Cache

Varnish is also available: Web Hosting - Wordpress CDN & Varnish Caching options

To request a CDN and receive your configuration credentials, email webhosting@doit.wisc.edu. Once you have your credentials, use the W3 Total Cache (W3TC) plugin to connect your site using the steps below.Web Hosting - Wordpress CDN & Varnish Caching options

Navigation Tips

• Saving: You must click the blue Save Settings button in the top right corner of any page for your changes to take effect.

• Getting Lost: If you get stuck in the plugin's menus, click General Settings to return to the main jumping-off page.

1. General CDN Configuration

• Navigate to Performance in your WordPress sidebar.

• Select General Settings.

• Scroll down to the CDN section.

• In the CDN Type dropdown, select Amazon Cloudfront over S3 (located under the "Origin Push" header).

• Click Save Settings.

2. Advanced CDN Configuration

• Navigate to Performance > CDN in the sidebar.

• Scroll down to the Advanced section.

• Enter your Access key ID.

• Enter your Secret key.

• Enter your Bucket name (e.g., dwh-edu.wisc.doit.webhosting.wwwtest.cdn).

• Set the bucket region to Ohio (or the region where your S3 bucket was originally created).

• Ensure Set objects to publicly accessible on upload is set to Disabled (don't apply an ACL).

• Click Save Settings.

3. Uploading Files and Managing the Cache

When you first set up the CDN, you need to push your existing files to the AWS servers.

• In the plugin settings, click the following upload buttons to push your site's assets to the CDN:

  • Host wp-includes/files

  • Host theme files

  • Custom files

• Initial Setup: Click Empty all Caches to ensure a fresh start.

• Routine Maintenance: Avoid clearing all caches regularly. Be surgical. Always verify in an Incognito/Private browsing window that an "old" file is actually stuck in the cache before clearing it.

4. Special Considerations & Troubleshooting

Using a Child Theme The plugin is not fully aware of how child themes work and may miss your parent theme files. Navigate to the Advanced section, find the Custom file list, and add the following path to ensure the parent theme is uploaded: {wp_content_dir}/themes/uw-theme/*

Automatic WordPress Updates If your site automatically updates WordPress core or plugins, the cache might fall out of sync. To prevent this, check the Export changed files automatically setting so the CDN updates alongside your site.

Temporarily Disabling the CDN If you need to troubleshoot an issue, do not deactivate the entire W3TC plugin. Instead, navigate to Performance > General Settings, scroll to the CDN section, uncheck the Enable box, and save your settings.