Noisetor is showing a significant, sustained drop in bandwidth usage starting approximately February 7-8. We've checked our setup and logs and there doesn't appear to be any sign of a causative factor here.
Throughout January and the first week of February we were averaging 400-500 Mbps. There was a pretty smooth decline down on the 8th, stabilizing at a "new normal" of 200-300 Mbps which we've maintained since then. (All these numbers are based on Munin graphs of eth0 throughput using the if_ plugin.)
I have some hacky Python that summarizes the torstatus.blutmagie.de data, and it appears that other exits didn't see a similar drop; but our drop came a few hours to days after torservers added a significant amount of new bandwidth. (However, total exit BW reported in torstatus did not increase much; if anything it seems to have gone down slightly.) Around the same time, Amunet rose from ~150 Mbps to ~450 Mbps and has remained in that range since.
Thoughts?
-andy