At 23:00(GMT+8) one of our servers became non-responsive. Due to this issue, and the volume of reviews, our software created a data dump into an XML file. This prevented users from logging into to their dashboards.
Resolution: After analysis of the issue, it was determined the quickest solution was to reboot our servers in sequence. We instituted additional monitoring, and added a routine to prevent a similar issue from reoccurring. We are actively monitoring the fix and no additional issues have been observed.