another bug: system time change

[Ondrej Zajicek]

On Fri, Apr 09, 2010 at 10:22:05AM +0200, Wolfgang Hennerbichler wrote:
> Hi Ondrejs, 
> 
> I think I found another bug. For some mysterious reason our system time jumped forward (more than 30.000 seconds) on one of our route-servers. I don't know why this happened, but I suspect a broken ntp server could have caused this. Nevetheless, this was reason enough for BIRD to drop the BGP peerings: 
> 

> You see the log-entries from the wtachdog, which is run every minute,
> all of a sudden the time jumps to 10:08 UTC, and BIRD brings down BGP
> sessions. Are the session hold timers dependent on the system time? 

That is really strange. On Linux 2.6, we use monotonic timers, which
shouldn't be affected by system time change. If monotonic timers are not
available (on Linux 2.4), we use system time but we detect time jumps
and ignore them.

-- 
Elen sila lumenn' omentielvo

Ondrej 'SanTiago' Zajicek (email: santiago at crfreenet.org)
OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3, wwwkeys.pgp.net)
"To err is human -- to blame it on a computer is even more so."
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