How long a period was this over? I can see downtime in the logs last night from 01:17 - 01:31, and then again for a moment at 06:37.
I'd be tempted to blame our hosts
I quite often seen a short 2-3 minute downtime in the middle of the night when they pause the database to back it up (front end server starts whinging that the back end db server is unavailable). I guess they took a full backup last night rather than incremental (being a Sunday night) and it took a bit longer than normal. Everything looks fine now.....
