On Thu, Aug 14, 2014 at 1:41 AM, Gergo Tisza <gtisza@wikimedia.org> wrote:

A workaround would be to add an extra parameter to height-constrained images, such as 623px-heightconstrained-Foo.png (as far as I can see, this is a non-scary change), and not purge files which have this parameter. A bit messy, but if the purging itself is also a temporary workaround until we have a new storage mechanism with proper usage-based cache eviction, there is no point messing with fundamentals of the thumbnail url syntax.

I'll clarify the context a little bit, I suggested cleaning up non-standard sizes to reclaim some storage space (if there are significant savings that is) but mostly to see if there were any easy wins to be gained.

If we end up complicating the setup significantly then I think we gain more by keeping it simple as it is now, of course if it helps going forward with moving thumbnails off swift then by all means I'm for it!

HTH,
filippo