[Dovecot] Time moved backwards

["Andraž 'ruskie' Levstik"]

On 15:48:42 2008-05-13 Bill Cole <dovecot-20061108 at billmail.scconsult.com>
wrote:
> At 11:31 AM +0400 5/13/08, Eugene wrote:
> >Hi Timo,
> >
> >From: "Timo Sirainen" <tss at iki.fi>
> >>>I suggest that Dovecot simply terminate the current connections
> >>>(causing the client to reconnect) or -- if the time change is really
> >>>that much of a problem -- to restart itself automatically.
> >
> >>I guess terminating all current connections and restarting all
> >>processes would be pretty safe, but it's not really a high priority
> >>change for me..
> >
> >Nevertheless, it would be very nice if you could fix it. It's a 
> >fairly big availability problem (for us, at least).
> 
> Then you have a badly broken system. There is no explanation for time 
> going backwards on a server on a frequent unplanned basis that is not 
> reducible to administrative incompetence or malfunctioning hardware 
> (and the latter as a chronic issue can be seen as just a special case 
> of the former.)
> 

Harsh...

> >And after all, if we are terminating already, adding a simple spawn 
> >call before that should not take much time?
> 
> A system clock that moves backwards is indicative of a problem. 
> Having a service respawn itself as a response to a problem that is 
> outside of its control (i.e. the respawn is not itself a fix) is 
> begging for trouble, because that behavior has to be carefully 
> controlled to prevent it from contributing to a cascading problem. On 
> a system whose clock is untrustworthy, this is a significant 
> challenge. The effort to do that sort of code correctly just to 
> accommodate
> people with broken systems seems like a terrible waste.
> 
> 
> On the other hand, writing a freestanding watchdog for a critical 
> service is (or at least should be) something any good sysadmin can 
> do. If you are stuck with hardware so broken that it jumps backwards 
> in time without warning but not so broken that you can get it 
> replaced, and it lives in a network or resource environment that 
> prevents you from fixing the core problem, you can adapt to the 
> breakage yourself.

I use monit for monitoring services... It so far has worked great... auto
restarts etc... depneding on configuration along with a web based interface
one can see a quick overview and control things(of course optional web
interface)

--
Andraž "ruskie" Levstik
Source Mage GNU/Linux Games grimoire guru
Geek/Hacker/Tinker

Be sure brain is in gear before engaging mouth.
Ryle hira.

Key id = F4C1F89C
Key fingerprint = 6FF2 8F20 4C9D DB36 B5B6  F134 884D 72CC F4C1 F89C