All true. The images should not be rethumb'd unless resolution changes, a new version is uploaded, or the cache is otherwise purged. However, on initial rendering, the thumb generation can be a large part (especially if rendering multiple images) of overall page execution time. Being able to offload this elsewhere should decrease that load greatly.
-Chad
On Apr 24, 2009 1:23 PM, "Roan Kattouw" roan.kattouw@gmail.com wrote:
2009/4/24 Aryeh Gregor <Simetrical+wikilist@gmail.comSimetrical%2Bwikilist@gmail.com
:
How long does it take to thumbnail a typical image, though? Even a >
parser cache hit (but Squid ... The problem here seems to be that thumbnail generation times vary a lot, based on format and size of the original image. It could be 10 ms for one image and 10 s for another, who knows.
Moreover, in MediaWiki's case specifically, *very* few requests should >
actually require the thu... That's true, we're already doing that.
So it's not a good case to optimize > for.
AFAICT this isn't about optimization, it's about not bogging down the Apache that has the misfortune of getting the first request to thumb a huge image (but having a dedicated server for that instead), and about not letting the associated user wait for ages. Even worse, requests that thumb very large images could hit the 30s execution limit and fail, which means those thumbs will never be generated but every user requesting it will have a request last for 30s and time out.
Roan Kattouw (Catrope)
_______________________________________________ Wikitech-l mailing list Wikitech-l@lists.wikimedia....