Antw: Re: Q: "dn: cn=Uptime,cn=Time,cn=Monitor" non-monotonic occasionally?

["Ulrich Windl" <Ulrich.Windl@rz.uni-regensburg.de>]

>>> "Brett @Google" <brett.maxfield@gmail.com> schrieb am 29.04.2016 um 11:50 in
Nachricht
<CAJiMZ95aOoN7pVAHKDzmamzkQCL9J6xKQoanSQCv=eq3daz0Cg@mail.gmail.com>:
> On Thu, Apr 28, 2016 at 6:48 PM, Ulrich Windl <
> Ulrich.Windl@rz.uni-regensburg.de> wrote:
> 
>> Hi!
>>
>> I'm running a NRPE monitor that monitors openLDAP. To compute delta
>> values, the NRPE plugin stores the "dn: cn=Uptime,cn=Time,cn=Monitor"
>> reported by openLDAP to compare it with the current value (to build the
>> time difference). If the time difference is negative, the plugin reports a
>> "server restart" event.
>>
>> So far, so good...
>>
>> However, very rarely (once every few weeks) a false server restart is
>> reported. Viewing the historic logs, I can only assume that openLDAP
>> reports a bad uptime value now and then. Could this be?
>>
> 
> If uptime is a calculation based on the system clock, is there some process
> such as ntpd or vmware tools, periodically updating the system clock,
> sometimes backwards ?

It should not, but the time could behave odd (jump) immediately after migration. I'll have to investigate this further.

> 
> If so, maybe look for an option to limit backwards updates.
> 
> Cheers
> Brett