Re: Standardisation of thumbnail sizes

This is great, and I'm sure many 3rd party installs will be glad of it 
too (to reduce their thumb storage requirements).

A couple of times lately I've had the "429 Use thumbnail steps listed on 
https://w.wiki/GHai" message, and because I'm a bit slow on the uptake I 
went looking for the steps to follow to get thumbnails. Has anyone else 
been confused by this? If it's just me, ignore this, but perhaps we 
could update the message to say "Use the values of $wgThumbnailSteps 
listed on…" instead.


On 24/1/26 02:27, Amir Sarabadani via Wikitech-l wrote:
> Thumbnails shown on-wiki are already quantized to a set of standard 
> sizes (if a non-standard size is requested, the next-larger standard 
> size is used, and scaled to the requested size by the browser). We 
> have recently extended the set of standard sizes, and are now moving 
> to only allow standard sizes to be used. Regular editing and viewing 
> will not be impacted by this change at all.
>
> * What isn't changing?
>
> Thumbnails served on wiki (via the "thumb" argument to File:, and via 
> the Media API) will continue to behave as they do now - if you request 
> a non-standard size, the next-larger standard size will be provided, 
> and scaled in-browser if appropriate.
>
> * What is changing?
>
> Requests for non-standard thumbnail sizes using other methods (e.g. 
> constructing an upload.wikimedia.org <http://upload.wikimedia.org> URL 
> with a non-standard thumbnail size) will be blocked by our CDN. These 
> are already being rate-limited for requests that we assess are not 
> coming from a web-browser.
>
> During this quarter, we will be broadening the scope of the existing 
> rate-limiting and making it increasingly strict, with the aim being to 
> refuse such requests entirely by the end of March 2026.
>
> * Why are WMF doing this?
>
> Historically, we have generated thumbnails of whatever size was 
> requested; this has been a drain on our thumbnailing infrastructure 
> and cost us in network bandwidth and storage volume. With the 
> increasing prevalence of highly aggressive scrapers, this has become 
> an intolerable burden on our network, infrastructure, and staff, who 
> have spent a lot of time over the holiday period working hard to keep 
> the wikis available for people to read in the face of automated abuse.
>
> * What do I need to do?
>
> Most likely, nothing: we have already tracked down some of the more 
> widely-deployed sources of nonstandard thumbnail requests (e.g. Popups 
> extension) and fixed them. If you own or operate something that 
> requests thumbnails by constructing a thumbnail URI directly, then now 
> is the time to either use the Media API instead or to make sure you 
> only request standard thumbnail sizes.
>
> * What are the standard thumbnail sizes?
>
> They are: 20px, 40px, 60px, 120px, 250px, 330px, 500px, 960px, 1280px, 
> 1920px, 3840px
>
> They are defined in config as $wgThumbnailSteps -
> https://gerrit.wikimedia.org/r/plugins/gitiles/operations/mediawiki-config/+/refs/heads/master/wmf-config/CommonSettings.php
>
> And also documented on MetaWiki -
> https://www.mediawiki.org/wiki/Common_thumbnail_sizes
>
> To help fix the existing instances, please see 
> https://phabricator.wikimedia.org/T414805 for search-links, and 
> examples of how to fix them.
>
> Best
> --
> *Amir Sarabadani (he/him)*
> Staff Database Architect
> Wikimedia Foundation <https://wikimediafoundation.org/>
>
> 	
>
>
> _______________________________________________
> Wikitech-l mailing list [email protected]
> To unsubscribe send an email [email protected]
> https://lists.wikimedia.org/postorius/lists/wikitech-l.lists.wikimedia.org/

_______________________________________________
Wikitech-l mailing list -- [email protected]
To unsubscribe send an email to [email protected]
https://lists.wikimedia.org/postorius/lists/wikitech-l.lists.wikimedia.org/