Maddy Gynoid pointed me to a notice the Lab has posted in Grid Status saying starting the Week of Nov 17th (Monday) they will be doing grid maintenance with one or more restarts per region per day.
Grid Status – Scheduled Maintenance
[Posted 10:00 AM PST, 14 November 2014] Beginning Monday, November 17, we will be undertaking a full week of scheduled maintenance. This maintenance will take place at approximately 7:00 AM each day next week. Each region will be subject to one or more restarts, as its host takes its turn for inspection. A five-minute warning will be broadcast for each restarting region. Additional warnings will be broadcast to regions where multiple restarts are necessary. Please be cautious about going AFK for extended periods in the middle of build sessions or handling no-copy objects, as you may miss the shutdown warnings. Please keep an eye on this blog for further updates.