Page cache purging inconsistent

[harrislapiroff]

Noticed that after @stephaniesugars updated this article cloudflare continued to retain the old cached copy.

Is wagtail's frontendcache contrib not working?

Left side was in a not-logged-in browser window, right side is logged in and thus bypassing cloudflare

[chigby]

We do have some amount of logging set up for this, so you can see that at least some cache purging events are being recorded:

Link to logs

[chigby]

From looking at this code, it's actually not clear to me that we ever intended that updating an incident page would trigger a cache purge for that specific page. Maybe it was an unintended consequence of the recently-removed "related incident" purging code?

[chigby]

Or maybe it was an intended consequence and we just forgot about it because there were no tests for that case specifically.