[Engineering] Proposal regarding the future of X-Wikimedia-Debug and testwiki

Wed Jan 27 08:17:54 UTC 2016

On Tue, Jan 26, 2016 at 11:58 PM, Mukunda Modell <mmodell at wikimedia.org>
wrote:

> I think it would be very useful to have a way to, in addition to
> cache-busting, also force the request to be served from the pre-production
> branch rather that the current production branch. This way changes on the
> prod+1 branch can be conveniently tested on any wiki (not just testwiki)
> while disregarding the version specified in wikiversions.
>

Well, there is a way: you can edit /srv/mediawiki/wikiversions.php on
mw1017 to change the mapping of wikis to branches, and set the
X-Wikimedia-Debug header to ensure your request gets handled by mw1017.
Making this more convenient would be very risky, because it would mean that
two different versions of the code are transacting with data on shared
storage backends, each with the presumption of being the only game in town.
And this state could be triggered by anyone, with no !logging or
coordination.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.wikimedia.org/pipermail/engineering/attachments/20160127/b15be15b/attachment.html>