The servers weren't quite able to keep up with their workload during the busy part of the day Thursday but are operating normally now. As load rises on Friday morning it is possible that service will degrade again. We are working on two fronts to address our overload problems: 1) deploying additional server capacity and 2) making a performance optimization in the software. One or both of these measures will be introduced on Friday to address our increased load.
The heavy traffic over the last few days is due to two things. First the transition to multiple calendars generates more work for the servers. Second, we have three times as many new users signing up every day than we did last week.
The status on the transition to multiple calendars is as follows: about half our users have had the feature enabled. Roughly 75% of their devices have made the transition. When we're sure that most of the eligible devices have transitioned and the current performance and capacity issues have been addressed, the remaining users will then be multical-enabled.
The web page that reports sync status and the elapsed time since the last successful sync will display incorrect information at present. This is because the recording of the status and error data has been temporarily disabled to reduce disk traffic (and improve overall reliability).