WP Super Cache 1.6.8 and Cloudflare
If you have a WordPress site, and you use both the WP Super Cache plugin and the Cloudflare content delivery network, the latest version 1.6.8 of WP Super Cache may not properly cache your pages by default.
This is because of a quirk of the update: A new setting makes it think all Cloudflare visitors are “known users” because they have a “cookie” set. If you had the old “disable caching for known users” option turned on before the update, it won’t cache pages for Cloudflare visitors after the update.
This problem is easily fixed by changing the new WP Super Cache “Cache Restrictions” setting from “Disable caching for visitors who have a cookie set in their browser” to “Disable caching for logged in visitors. (Recommended)”. We’ve updated our WP Super Cache page to reflect this change, and if we notice that a site hosted on our servers suddenly has higher CPU resource usage because of this, we’ll update the setting for you to make it work as it did before.