We are back after almost 2 days of downtime.
Our hosting provider is not very communicative, which is why we currently have no information about what caused it or how they fixed it. All we know from our logs is that the server itself was fine until they *tried* to fix the problem a few hours ago. Unfortunately, they messed up and shut down the server improperly so we had to restart everything, including the tracker, so the most recent peer data is lost, which might result in some up/download traffic not being counted.