The stats db hung last night around midnight pacific time. We saw that it was down this morning (we get emails from the stats system when there hasn't been an update in over 2 hours) and we restarted the stats db. A stats update is now in progress and should continue to run.
We will keep an eye on this over the weekend in case there's some greater systemic problem here. Please note that we have a reduced admin staff on the weekends, so response will be a bit slower.