The number of Apache busy workers on the image scalers spiked between 2:55
and 3:15 UTC, peaking at about 3:12 and overwhelming
rendering.svc.eqiad.wmnet for about a minute.
The outage correlates fairly well with a spike of fatals in
TimedMediaHandler, consisting almost entirely of requests to this URL: <
http://commons.wikimedia.org/w/thumb_handler.php/2/2c/Closed_Friedmann_univ…
.
The full stack trace is included in <
https://bugzilla.wikimedia.org/show_bug.cgi?id=64152>gt;, filed by Reedy
yesterday. It appears File::getMimeType is returning 'unknown/unknown' and
that File::getHandler is consequently not able to find a handler.