[tor-relays] relay bangs into rock; falls off cliff; recovers

[starlight.2015q2 at binnacle.cx]

Identified the issue:

Problem occurs when the client function
in the relay daemon cannot establish
circuits to the guard for any reason
whether because it's down or because
DDOS/sniper attack rate limiting
has been activated by the guard.

This shows up most obviously when
the guard(s) are manually configured,
but it's noticeable in the Vidalia graph
that traffic locks up for some large
fraction of a second when circuit
creation is under way under otherwise
normal operation.

Something is taking control away
from the event loop for much longer
than correct implementation
recommends.

opened trac ticket:

#16585 relay stops forwarding all traffic when client function cannot establish circuit
https://trac.torproject.org/projects/tor/ticket/16585