Re: odd clock jump messages from 0.2.0.21-rc

[Roger Dingledine <arma@xxxxxxx>]

On Sun, Mar 16, 2008 at 01:27:38AM -0500, Scott Bennett wrote:
>      Something weird seems to be happening several times a day since
> I installed 0.2.0.21-rc.  The tor traffic drops to nothing suddenly
> and a message is logged claiming that the system clock has jumped
> forward some number of seconds and that all circuits are assumed to
> be unusable.  (That assumption seems to me unwarranted for relatively
> short jumps of the system clock, but that's a separate issue.)  In any
> case, I haven't spotted any other evidence in my system that the clock
> has indeed suddenly jumped forward.  Only tor is claiming that it has.
[snip]
> Mar 15 14:05:55.095 [warn] Your system clock just jumped 111 seconds forward; assuming established circuits no longer work.
[snip]
>      I don't recall seeing these messages prior to 0.2.0.21-rc unless I did
> something that would change the system clock.  What has changed that could
> possibly be affecting tor's mechanism for determining whether it has been
> unexpectedly dormant?

See also the previous thread on this topic:
http://archives.seul.org/or/talk/Feb-2008/msg00285.html

In this case, Lucky found the problem was that he was running with
multiple CPUs, and vmware kept track of time differently on each CPU
(different meaning they were several hours apart from each other). So
when Tor moved from one CPU to the other, its time changed wildly.

It sounds like that's not what's happening here. But are you on more than
one cpu (or more than one 'core', now that we're in the 21st century)?

I've also heard from some FreeBSD users who had problems with the clock
jump warnings, and once they upgraded their kernel sufficiently the
complaints went away. I don't think you mentioned what OS you're using,
but it looks like you're using FreeBSD too?

The other option is that you're massively swapping and Tor really is
getting starved for hundreds of seconds at a time. But I'm guessing
that's not it.

--Roger