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Invalidate full cache of math image on WMF
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Description

Please invaldiate/delete the full cache for the rendered math-tags.

After Bug 8 was fixed (go live on 9. April 2010 on the cluster) the old images are all still shown. When have a skin/user style with a non-white backgound, then it looks bad, when one math-tag has a transparent background and the other a white, because the first is rendered after the 9. April 2010.

See also bug 16719.

Thanks.


Version: unspecified
Severity: normal

Details

Reference
bz24445

Event Timeline

bzimport raised the priority of this task from to Low.Nov 21 2014, 10:59 PM
bzimport set Reference to bz24445.

Maybe we could purge the math subfolders (4096 of them) one by one for files before april 9 2010.
We would need some metrics to track the math generation though.

Another option would be to edit the pngs in place to add the transparency. Feels dirty, though.

(In reply to comment #1)
I believe this has been disucssed (unsure if it was for clearing the whole lot or just the ones that need it. But there are load issues to contend with.

You can't delete the images, because they are referenced from cached HTML. Unlike thumbnails, there is no way to regenerate them without parsing the articles that refer to them, because only the hash is known, the source LaTeX is not stored in the math table.

Perhaps we could change the base directory and URL, and have a 404 handler that falls back to the old math directory when an image doesn't exist in the new directory. Then after a few months, we could delete the old directory.

That would be a one-off though. A more permanent solution would be to change the schema, direct all math requests to a script, and implement expiry in MediaWiki.

  • Bug 29770 has been marked as a duplicate of this bug. ***

[20:57] <p858snake|l> (Bug 24445) have we ever really thought about the math cache load issue if we were to totally rebuild it on the wmf cluster? because for 1.18 with how we have it version switched in intsettings we could point it to a new folder to rebuild... but the week turn around between adding more projects is probably to short to do that

nmichalo wrote:

*** Bug 15057 has been marked as a duplicate of this bug. ***

Looks fixed? Can someone confirm, that there are no pngs with white background exist in cache? Thanks.

Can someone confirm, if this is already fixed? Thanks.

Please add a status info. Thanks.

Math pictures looks good, so there was some changes. Thanks.