Thread:Project:Support desk/InstantCommons ... images disappeared/reply

The images reappeared. I noticed the problem at around 9:30 MDT and it resolved itself somehow at around 21:30 MDT.

I wish I could better understand the parameters associated with the InstantCommons -- that are described here: https://www.mediawiki.org/wiki/Manual:$wgUseInstantCommons

Specifically, it would be useful to understand how 'descriptionCacheExpiry' and 'apiThumbCacheExpiry' control the behaviour.

To describe the problem better: The image pages for the images disappeared (e.g. was gone): it is as if the files were all deleted from the cache and the images non-existent on wiki I am running.

The default value for 'descriptionCacheExpiry' is 12 hours. This leaves me wondering whether the issue is related to the cache.

As I upload to the commons (I have ~2000 original contributions) -- and use the InstantCommons -- I have noted that images removed from the WikiCommons subsequently disappear from the wiki I am running. I think it is good that things removed from the Commons get purged from down stream wikis. Preceding said, I cannot but help wonder about the bandwidth usage and whether there is a bug in this somewhere. On the downstream end of the WikiCommons, it would be nice to have notification (tracking) that an image is being purged, as it creates a breakage.

I suspected that the 'CacheExpiry' variables are essentially the interval between when the downstream wiki checks the Commons for an updated version/whether the file on the WikiCommons has been removed from the commons.

In any case, I hope to hear from someone familiar with the internals here -- as I really hope there isn't a repeat of this.