We had a site outage because memcached on wiley crashed. This caused all of the web front ends to crash with the previously seen error message:
2011-11-28 17:31:50.495995500 [error] Caught exception in engine "Couldn't save expires:c1c611ace1febf8bc148e4a72d67ccbce510332b / 1322508709 in memcached storage"
(this message was taken from
MBS-3590). Once I started memcached on wiley, everything came back up.
We need to ensure that if memcached is down that the site can still continue (all of musicbrainz.org was down because of this), even if users cannot use the release editor.