Skip to main content
How Can We Help?

CDN Problems

Posted
Updated
ByEmily Gomez
A Content Delivery Network (CDN) can improve website performance by storing and serving cached copies of your site’s content from servers closer to your visitors.
In some configurations, a CDN may serve outdated content or interfere with how an experiment is delivered by Bluvia A/B Testing.
If you’ve already cleared your WordPress and hosting caches but an experiment still isn’t displaying as expected, your CDN may be the next place to check.

Signs Your CDN May Be Affecting an Experiment

A CDN may be involved if:
  • An older version of a page continues to appear after clearing your WordPress cache.
  • Recent Variant changes aren’t appearing on the live website.
  • A Variant works correctly in Preview but not for live visitors.
  • Changes appear for some visitors but not others.
  • Purging the CDN cache temporarily resolves the issue.
Before troubleshooting your CDN, confirm that the experiment is Active and configured correctly.

Confirm Whether Your Website Uses a CDN

Your website may use a CDN even if you didn’t configure one directly.
CDN functionality may be provided through:
  • Your hosting provider.
  • A WordPress performance service.
  • A separate CDN provider.
  • A website security or optimization service.
If you’re unsure whether your website uses a CDN, check your hosting or website performance configuration.

Purge the CDN Cache

Clearing your WordPress cache doesn’t necessarily clear content stored by your CDN.
If your CDN provides a cache purge option, clear the cached content for the affected page or website.
After purging the CDN cache:
  1. Visit the page included in the experiment.
  2. Confirm that the latest version of the page is being served.
  3. Preview the Variant.
  4. Check that the expected content and functionality appear correctly.
Bluvia A/B Testing uses cookies to maintain a visitor’s experiment assignment, so refreshing the page won’t necessarily cause you to see a different Variant.
Use Preview when you need to inspect a specific Variant.

Pause the Experiment When Troubleshooting

If you need to determine whether the problem exists independently of the experiment, temporarily pause the test.
Then:
  1. Pause the experiment.
  2. Clear your WordPress and hosting caches.
  3. Purge the CDN cache.
  4. Visit the original page and confirm it works correctly.
  5. Preview the Variant separately.
  6. Compare the original experience with the Variant.
If the issue continues while the experiment is paused, the problem may be related to your website or CDN configuration rather than the experiment itself.
Once troubleshooting is complete, review the experiment before resuming it.

Review CDN Optimization Features

Some CDNs provide optimization features in addition to caching.
These may include:
  • JavaScript minification
  • Script deferral or delayed execution
  • Script combining
  • HTML optimization
  • Automatic page optimization
These features can change how website resources are delivered or executed.
If the page is current but experiment functionality isn’t working correctly, review any optimization features that modify JavaScript.
For more information, see JavaScript Conflicts.

Avoid Broad CDN Changes

CDN settings can affect your entire website, so avoid disabling caching or optimization across your entire site unless necessary.
If you’re testing whether a particular CDN feature is causing the issue, make one change at a time and check the experiment again.
This makes it easier to identify the setting responsible without unnecessarily changing the rest of your website’s configuration.

After Making Changes

Once you’ve adjusted your CDN configuration:
  1. Purge the CDN cache.
  2. Clear any WordPress or hosting caches.
  3. Confirm that the original page works correctly.
  4. Preview the experiment’s Variants.
  5. Resume the experiment if you paused it.
  6. Monitor the live experiment to confirm the issue has been resolved.
Avoid stopping an experiment while troubleshooting unless you’re finished running the test. Stopped experiments are completed and cannot be resumed.

Still Having Trouble?

If you’ve confirmed that your experiment is configured correctly and believe your CDN is interfering with Bluvia A/B Testing, contact Support.
When contacting Bluvia A/B Testing Support, include:
  • The experiment name.
  • The URL where the issue occurs.
  • The CDN or website optimization service you’re using.
  • A description of what you’re seeing.
  • Whether the issue affects the Control, Variant, or both.
  • Whether the Variant works correctly in Preview.
  • Whether purging the CDN cache changes the behavior.
  • Any CDN optimization features you’ve already tested.
This information can help the Support team identify whether your website’s delivery configuration is affecting the experiment.

Related Articles

Continue with: