Tor Question

[Roger Dingledine]

On Tue, Aug 01, 2006 at 10:02:57PM -0500, Arrakistor wrote:
> I  have  a  question.  I  noticed  in some code that it said if tor is
> running  on  a  win32  system,  to  disable signals. So even if I sent
> signals  like sighup to the process, it wouldn't be listening. Is this
> true?

Correct. Windows doesn't have signals, so there is no concept of sending
a sighup to a Windows process.

We fake this by letting you connect on the controlport and send the string
"signal hup", aka "signal reload". Then Tor behaves as though you just
sent it a unix-style signal.

> Also,  what kind of damage does it do to the tor network for a node to
> just instantly disappear without notifying the network?

Any circuit that's currently using that node breaks. So if a user has a
long-term IRC or IM connection on that circuit, she gets disconnected.
Tor will automatically recover and build new circuits, but the application
will have to reconnect over the new circuit.

We try to tolerate nodes that appear and disappear frequently, by avoiding
them when building circuits for destination ports that we expect will
want high uptime: see LongLivedPorts in your manual page. After all,
servers will have to disappear and reappear periodically.

But if they aren't online very long, new clients won't have time to hear
about them from the directories, so we won't be able to make good use
of them. This is another item on our list of hard things that ought to
be fixed. :)

Why do you ask?

--Roger