I decreased a customer’s response time to 30ms by configuring the “Edge Cache TTL” but it won’t respect any caching header. As I understand (definily I can be wrong) TTL should be the “Maximum Time To Live” not the “Exact Time To Live”, enabling this settings made CloudFlare’s edge location cache the admin bar on some pages (when an authenticated admin is the first person to visit it), even when Cache-Control is set to “private” or “no-cache” and Expires is set to “0” or “-1”.
So I disabled this setting and the response time now ranges between 30ms (when requesting a URL by the second time under 5 seconds after the previous request) and 1.5s (when it goes to the origin - yes, the server is really far… but the customer won’t move it, I am unable to understand why - And it happens quite often) .
Is it the intended behaviour? If it is, is getting the business plan the only way to keep a more persistent cache on the edge location without showing the WordPress’ admin bar to anonymous visitors?