There have been two instances when this happened that I'm aware of. Both were around the same time of day. It hasn't happened since, to my knowledge.
Regarding server capacity, we have a server that runs the forum that I can allocate resources to dynamically as we need them. I happened to have upgraded the capacity not long before this began happening to use more processor cores. The server has far more capacity and processing power than it needs.
I also contacted our server provider about it and they didn't see anything on their end. I just assumed it was a glitch since it stopped after happening twice, back to back days (11/20-11/21).
Are you having problems with it today?
Shane