I Just got a report of another similar looking notification. We are doing an AMA and have a few more people than usual reading and posting in the forum, but I am not convinced that this is extreme load. Maybe a plugin like Who's Online Plugin (discourse-whos-online) is causing additional load?
Thanks! I will look into this now.
Is there a way to disable these in an admin setting and just let people wait if it is getting slow? I think our site is still not especially busy.