Hi,
the m2 master crashed today (investigation still ongoing), and caused EventLogging to not be able to write events to the database on 2014-11-18 between 14:14 and 15:02.
The data for that period is not lost, but is available in backup files, waiting to get injected again into the database.
Just wanted to let you know what happened, in case you notice drops in graphs / dashboards during that period.
Sorry for the inconveniences, Christian