thanks for the blogpost, could be very useful for others.
to be clear; it is no coincidence AO does not have its proper automatic cache purgin, as such a system could break sites if the page cache would not be cleared at the same time (see FAQ). as you are purging wp-content/cache, you are very likely also purging your page cache at the same time, which limits the risks.
still this scenario which might cause problems;
* yesterday you had HTML_A in your page cache with Autoptimized file AO_1, both 6 days old
* today you have a request for new HTML_B with the same aggregated CSS (or JS) code, this results in HTML B also using AO_1
* tonight you’ll have your cron job running, which will purge HTML_A and AO_1 and will leave HTML_B in place as it’s not 7days old yet
result: a badly broken HTML_B
the FAQ also explains why cache sizes might balloon and how to prevent that (don’t aggregate inline JS is the easiest solution in 99% of cases).
hope this clarifies!
frank
