[Labs-l] beta: upload cache is now using varnish

[Antoine Musso]

Le 10/07/13 10:39, Antoine Musso a écrit :
> Hello,
> 
> The beta upload cache has been migrated this morning from an old Lucid +
> Squid instance to a Precise + Varnish instance.
> 
> That has been made possible with:
>  - Mark Bergsma refactoring the varnish class to make them realm
> agnostic and thus applicable on a labs instance
>  - Ariel Glenn setting up a media server emulation (deployment-upload)
> from which to fetch thumbnails.
> 
> We also got HTTPS enabled there :-]
> 
> The test page with some nice cute polar bear is:
>  http://en.wikipedia.beta.wmflabs.org/wiki/File_talk:Polar_bear.jpeg
> 
> And with HTTPS (though you will have to manually accept certificates):
>   https://en.wikipedia.beta.wmflabs.org/wiki/File_talk:Polar_bear.jpeg
> 
> If you see any glitch when uploading pictures, trying a feature or
> uploading a new version, that might be related to that migration.

We have spotted a few bug thanks to this deployment.  That will
definitely help deploying the varnish cache for text in production.

Example of bugs fixed:

  Varnish eating cookie, making it impossible to login
    https://bugzilla.wikimedia.org/51988
    https://gerrit.wikimedia.org/r/75842

  Some varnish vcl was not properly proceeding the cookies.


  http://login.wikimedia.beta.wmflabs.org/ trapped in a redirect loop
    https://bugzilla.wikimedia.org/51700
    https://gerrit.wikimedia.org/r/#/c/75583/

  While Squid do not cache redirects, the Varnish does. When the
  redirect is different based on http/https, we needed to make the
  cache vary.


Thanks to Mark Bergsma help in debugging those and his responsiveness,
they got fixed quickly after being discovered =)

-- 
Antoine "hashar" Musso