There seem to be some off-and-on CSS issues (not always reproducible) that harm a lot of people and are likely interconnected to some extend.
Please chime in if you have ideas.
Pasting the list so far: * Page reload error "mw.getConfig is not a function" with Monobook: https://bugzilla.wikimedia.org/show_bug.cgi?id=42192 - mdale wrote that it "appears the resource loader is doing something strange, or at least inconsistent with debug mode and when vector skin is active." * Diffs not colored: https://bugzilla.wikimedia.org/show_bug.cgi?id=42193 * Missing Gadgets tab (also with Vector skin): https://en.wikipedia.org/wiki/Wikipedia:Village_pump_%28technical%29#Missing... * http://en.wikipedia.org/wiki/Wikipedia:VPT#Style_sheet_changes * Editing articles on mr.wikipedia has overlays issues for anon users, makes text unreadable (also with Vector skin): https://bugzilla.wikimedia.org/show_bug.cgi?id=42170 * "WikiEditor panel not loading": https://de.wikipedia.org/wiki/Wikipedia:Fragen_zur_Wikipedia#Fehlerhaftes_Fa... * Maybe also: Edit conflict sometimes does not show the current text: https://bugzilla.wikimedia.org/show_bug.cgi?id=42163
Speculation:
Looking at the monthly stats on http://ganglia.wikimedia.org/latest/graph_all_periods.php?c=Bits%20applicati... (click on "Inspect") there is a drop of "Out" on November 5/6th.
From http://wikitech.wikimedia.org/view/Server_admin_log#November_5 :
21:54 aaron synchronized wmf-config/mc.php 'Switched all wikis to memcached-multiwrite.' 21:54 logmsgbot_: aaron synchronized wmf-config/InitialiseSettings.php 'Disabled spammy (with pecl memcached) memcached.log, the useful one is memcached-serious.'
Also Reedy mentioned on IRC that "Peter did some bits apaches upgrades to 12.04 yesterday".
Help welcome.
(Thanks to RobLa for pointing to Ganglia and Bits there.)
andre