TYPO3 Core

Good catch. It is true that config.cache_period only affects the page cache. This indeed makes sense, because this cache defines when a page rendering is repeated. The page cache is affected by "Cache Lifetime" in each page settings, then config.cache_period and config.cache_clearAtMidnight. Since 4.6 the page content is taken into account when calculating when the page cache expires (i.e. if you have a "starttime" element and it starts before the cache would expire, this lifetime is adapted accordingly). Great stuff (#20473).

This is all working well also in 6.x.

Now comes the "cache_pagesection". This contains the "configuration" of the pages (rootline, typoscript, conditions, etc). This is content-independant and usually should not expire so fast. In fact, in 4.5 it did not even expire at all (only when you hit "clear all caches").

Arjen interpreted it right:

This was not adapted when we introduced the caching framework for this (which was turned into the default in 4.6).

My suggestion would indeed be to rise this caching lifetime to something much higher than "1 hour" as it is today. Even "1 day" is too little in my understanding. The relevant caches are invalidated when something changes anyway. So we could cache this for a much higher lifetime (1 week or more) in my opinion and set this a new default.

I would not go for "unlimited" as this has caused some huge cache_pagesection-tables in the past. A decent default should suffice.

Patch set 1 for branch master of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/27228

Applied in changeset 097cd54ee02026988eed797392bbe17eeda966e0.