maximillianos - 1:45 pm on Sep 24, 2010 (gmt 0)
This same thing happens to my server on a much smaller scale. If my memcache were to suddenly think all cached objects needed to be replaced, my server crumbles to it's knees while the db gets hammered.
It is a risk/ tradeoff of highly cached system.
I can only imagine the issues they face at the scale they deal with. So much dynamic content. Crazy.