I'm running a pretty strong Tor Middle Relay, not a Guard yet - at least the CPU is good for a Tor Relay - and somehow my server experiences extreme usage right now, and in the picture we can see that something is clearly off. Somehow, Tors download is at 5.9MB/s but upload only 4MB/s.
And what you can't see is Tors extreme resource usage of 1GB RAM (usually it's a half GB only) and - the processor at full 3GHz - 30% CPU usage of 4 cores, while usually I only get 10% CPU usage at 800MHz.
And when looking at htop, it's pretty clear Tor is being DoSed to dead right now, because Tor uses 100% of one full core... Well, it fluctuates between 70% and 110%.
By the time of writing, the DoS attack is still going on..
So, what could I do? Right now, still writing, the DoS has stopped.
So, lucky that it stopped, I wonder why and how this could happen.
I personally think, there could be one possible reason:
- Tors DoS protection is bad and someone requested something over and over, resulting in high download and lots of processing.
So I wonder, if that was a new Tor vulnerability or something. I'm stuck here and don't know what to do, because I am very sure that this was a DoS attack and I'd like to inform the developers in case it really was one.
The softwares version is, according to nyx, Tor 0.4.7.12 (recommended).
Note: RAM usage still 1GB. I guess, the RAM usage usually is 1GB, though I had seen it mostly using around 512MB lately.