Since this day's noon BibSonomy is running in normal operation again. As we already said, the downtime was caused by a power outage in our neighborhood.
We try our very best to ensure 24/7 operation and we truly are aware of our responsibility. For handling power outages, we already distributed our server load over two independent UPSs (uninterrupted power supplies). A separately installed process monitors all our vital services and sends out pager messages to all responsible BibSonomy team members. The same was true last night - and accordingly our system administrator was on-site short after the power outage occurred. But their was nothing he could do, as the power outage lasted two long for our university's Internet main routers.
Until noon there were still issues connected with wrongly configured routers due to the blackout. But during the last few hours we monitored our systems and are now sure that everything is back to normal. For managing longer power outages in future we installed another UPS. Some permanently installed switches remain to be connected to the new UPS by a technician who already is scheduled.
As a consequence of this downtime which lasted way too long we enforce our activities in distributing BibSonomy's installation across two geographically independent locations. We hope that we didn't cause too many problems and we are really sorry for all inconveniences!
Keep on tagging!
.folke