[tor-relays] 100K circuit request per minute for hours killed my relay

[Vort]

>      This sort of thing has been going on for many years.  I used to refer
> to it as "mobbing".  As nearly as I was ever able to determine, the behavior
> is an unintended consequence of hidden services.

Same thing started to happen today and I have noticed that 100% CPU
  usage spikes happens every hour and lasts for several minutes.
During this spikes, all cores of CPU are used and stack trace points
  somewhere at worker_thread_main() function.
Also today relay have more connections than usually (5500 vs 2000-3000).
Is this pattern matches the characteristics of hidden services work?


Jul 27 16:09:12.000 [warn] assign_to_cpuworker failed. Ignoring.
...
Jul 27 17:09:13.000 [warn] assign_to_cpuworker failed. Ignoring.
...
Jul 27 18:08:31.000 [notice] Circuit handshake stats since last time: 5198/5200 TAP, 3994625/3995090 NTor.
...
Jul 27 18:09:11.000 [warn] assign_to_cpuworker failed. Ignoring.
...
Jul 27 19:09:11.000 [warn] assign_to_cpuworker failed. Ignoring.
...
Jul 27 20:10:11.000 [warn] assign_to_cpuworker failed. Ignoring.


-- Vort