Brian Reichert wrote:
> (This question also went to the regular mailing list, but I hadn't
> seen any feedback yet, and was feeling twitchy. :)
>
> Hello, folks; hopefully someone could provide some advice on a
> certain matter.
>
> We've been mucking with an LDAP cluster that's managed via heartbeat.
> We have code that's supposed to manage expiring records when they're
> stale. We test our code by manually setting the system time (across
> all hosts) four months into the future.
>
> When we do this, we see heartbeat go into a tizzy, and lose the
> virtual interface (eth0:0). Oddly, the host still has this virtual
> IP associated with it, but heartbeat has lost track of it. Only a
> reboot seems to re-instantiate it.
>
> If I set the time back to the present, I see a useful message in
> the logs:
>
> info: Clock jumped backwards. Compensating.
>
> I tracked this diagnostic to LookForClockJumps(), and noticed that
> there was logic to detect a backwards skew of the system clock, but
> there was no logic to detect a pathological skew forward.
>
> Two questions:
>
> - Should setting the time for four months into the future have
> caused the symptoms we saw? This are _very_ reproducible.
>
> - Would a check for an unreasonable forward skew have prevent this
> symptom?
>
> This is on Red Hat 4 update 3, kernel version 2.6.9-34.ELsmp, and
> heartbeat 2.0.4.
>
> I noticed the LookForClockJumps() has not changed 2.0.7.
>
> (I also noticed no Red Hat RPMs for 2.0.7, but that's a separate
> observation. The supplied spec file is failing me. :)
>
> I can provide heartbeat logs, and tcpdump capture files, if anyone
> wants to poke.
>
> Anyway, I'd appreciate any advice/pointers you folks could provide...
Can you send me the logs? Did you have debug on?
Heartbeat really doesn't care about the time of day clock.
HOWEVER, there is a bug for one period of 40.96 seconds every 400 days
or so. In theory you could have jumped into that range. In practice,
it seems unlikely.
--
Alan Robertson <[EMAIL PROTECTED]>
"Openness is the foundation and preservative of friendship... Let me
claim from you at all times your undisguised opinions." - William
Wilberforce
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