| | 3 | If you use something like allkeys-lru, then the only way actively-used keys could get evicted is if your cache is too small - a hosting error, not WP. If you do want to use TTL/expire on specific keys, then perhaps volatile-lru could be used. It seems to me that this decision should be up to the site owner, not WP Core. |
| | 4 | |
| | 5 | This all seems to roughly echo what Peter Wilson said in his initial comment: https://core.trac.wordpress.org/ticket/57625#comment:3 |
| | 6 | |
| | 7 | Perhaps a solution the present problems is to give users and plugins more control over caching policies such as whether to apply a TTL or not to a specific cache key? Also, to provide documentation/guidance on proper server cache (redis) config - both for users who manage their own servers, as well as for hosting providers to do a better job at. |
| | 8 | |
| | 9 | This article from Ruby on Rails goes into detail about using key-based cache expiration, so it seems worth reviewing for inspiration. |
| | 10 | https://signalvnoise.com/posts/3113-how-key-based-cache-expiration-works |
| | 11 | I hope this is helpful rather than irrelevant/a distraction! |