[tor-relays] Minimizing service interruption when reloading torrc?

[Roger Dingledine]

On Mon, Feb 09, 2015 at 04:29:01AM +0100, Sebastian Urbach wrote:
> >I'd like to reload torrc; I think I can do this by either restarting tor or
> >by sending a SIGHUP to the tor process, but I'm not sure how much of a
> >service interruption each of these approaches will cause.
> >
> >What's the best way to reload torrc (i.e. how can I do this in a way that
> >minimizes the service interruption)?
> 
> If it is just reloading the torrc and nothing else then SIGHUP ie
> the best way to do that.

If you're using the deb, "service tor reload" is slightly better --
this init script will run Tor on your torrc with --verify-config first,
in case it notices anything that is going to make your Tor exit when it
parses the new torrc.

If the Tor run with --verify-config complains, then the init script will
opt not to send the hup signal, and instead give you a warning.

The goal is to reduce the number of situations where you hup your Tor
and then it quietly writes out a complaint about the new torrc file and
exits, but you don't notice that it's gone.

--Roger