CPU at 100%, nyx logs a warning


My newish relay, “CatButler,” started reporting continuous CPU spiking last week (see graph). At the same time, Nyx started reporting:

20:40:49 [WARN] Your computer is too slow to handle this many circuit creation requests! Please
│ consider using the MaxAdvertisedBandwidth config option or choosing a more restricted exit policy.
│ [33864 similar message(s) suppressed in last 60 seconds]

I have a standard torrc (nothing changed from default), including:
ORPort 9001
ORPort [2a03:b0c0:3:d0::1183:e001]:9001
Nickname CatButler
DirPort 9030
ExitPolicy reject :




Most likely, it’s a result of DDoS attack on Tor network, which is going on for about half a year.

It’s caused by the current DDoS. You can mitigate that by using some iptables rules. You have two choices:


Take your pick.

After you run the iptables rules, I also suggest that with your bandwidth, you increase the NumCPUs in your torrc to about 16-20. Just type NumCPUs 20 somewhere in your torrc file.

These are the effects of DDOS against Tor. No worry we all strugle with this.

Thank you all for your comments.