Forum:How to .. refresh an image thumbnail

I don't upload too many images and when I do I rarely worry about how their thumbnail's appear in an article but today I do care and I am a little perplexed as to what is going on.


 * 1) Image placeholders (specified as 180 pixel thumbnails) appear in numerous articles as red links. See http://vsk.wikia.com/wiki/Rule_18.1 for an example article. (I am not using the new placeholder feature.)
 * 2) Upload an initial draft of an image. The source is 630x580 pixels.
 * 3) Refresh the wikipage that uses this image.
 * 4) * I notice that certain lines are not thick enough to stand out in the thumbnail image so I edit the source and ...
 * 5) Upload a new version of the image. (630x580 pixels)
 * 6) Refresh the wikipage that uses this image.
 * 7) * The image thumbnail does not change!

By right clicking on the thumbnail I find the fullurl to the 180px thumbnail (it is  http:// images2.wikia.nocookie.net/vsk/images/thumb/d/d7/Rule18.1a_na.png/180px-Rule18.1a_na.png) so I paste that URL into my browser address bar and can see that indeed the 180px thumbnail image has not updated yet. So I tack on a ?action=purge and yield: http://images2.wikia.nocookie.net/vsk/images/thumb/d/d7/Rule18.1a_na.png/180px-Rule18.1a_na.png?action=purge
 * Sure enough the image refreshes at the above URL but...
 * Back at the wiki page any number of refreshes (action=purge) or null edits (edit/save-with-no-changes) or previews does not cause the new thumbnail to appear in the article.

Is there some other trick to cause an image thumbnail to refresh after a new version of the image has been uploaded?


 * ANSWER: Ctrl+F5 (or Ctrl+Shift+R for Firefox) causes the correct thumbnail image to be displayed.

--najevi 14:00, September 8, 2009 (UTC)

adding ?action=purge to the long form url doesnt actually purge it, the reason you are seeing a different the now correct image is you have asked for a different url entirely. you could have put action=pudding at the end, and it would have done the same thing. the servers (or the cdn) have cached the old/wrong image at that exact url that you see as broken.

action=purge only actually does something if used on a wiki page, where it is passed on to some lower level things, and cached thumbnails in mediawiki are thrown away, this does not always correctly get sent to our outer caches right away (we use varnish), and may also take a while for the invalidate message to get to and be processed by the CDN (i think we still use panther)

either way, purge, wait 30-45 seconds, then do the hardrefresh (the ctrl+something based on your browser). --Uberfuzzy 00:20, September 9, 2009 (UTC)