I ended up doing some digging today and thought I’d share my findings. I’m working with a client who’s 8.2 Sitecore instance is filling up the isLanguageFallbackValid cache and then some. This cache size appears to be controlled via Sitecore’s “Caching.SmallCacheSize” setting. I thought I’d share as a quick Google search didn’t immediately reveal anything.
While we’re on the subject of caching and sizing I should probably mention the “Caching.DisableCacheSizeLimits” setting. Disabling the cache size limit can be a great way to see what your Sitecore instance is actually using so you can plan accordingly (via /sitecore/admin/cache.aspx). Whether or not you can leave this set on is another matter. This article by Uli Weltersbach is worth a read: https://reasoncodeexample.com/2013/03/20/sitecore-cache-settings-for-slackers/