clock syncronisation

clock syncronisation

[Stefan Priebe - Profihost AG]

Hello list,

is there any prefered way to use clock syncronisation?

I've tried running openntpd and ntpd on all servers but i'm still getting:
2012-11-08 09:55:38.255928 mon.0 [WRN] message from mon.2 was stamped 
0.063136s in the future, clocks not synchronized
2012-11-08 09:55:39.328639 mon.0 [WRN] message from mon.2 was stamped 
0.063285s in the future, clocks not synchronized
2012-11-08 09:55:39.328833 mon.0 [WRN] message from mon.2 was stamped 
0.063301s in the future, clocks not synchronized
2012-11-08 09:55:40.819975 mon.0 [WRN] message from mon.2 was stamped 
0.063360s in the future, clocks not synchronized

Stefan

Re: clock syncronisation

[Wido den Hollander]

On 08-11-12 10:04, Stefan Priebe - Profihost AG wrote:
> Hello list,
>
> is there any prefered way to use clock syncronisation?
>
> I've tried running openntpd and ntpd on all servers but i'm still getting:
> 2012-11-08 09:55:38.255928 mon.0 [WRN] message from mon.2 was stamped
> 0.063136s in the future, clocks not synchronized
> 2012-11-08 09:55:39.328639 mon.0 [WRN] message from mon.2 was stamped
> 0.063285s in the future, clocks not synchronized
> 2012-11-08 09:55:39.328833 mon.0 [WRN] message from mon.2 was stamped
> 0.063301s in the future, clocks not synchronized
> 2012-11-08 09:55:40.819975 mon.0 [WRN] message from mon.2 was stamped
> 0.063360s in the future, clocks not synchronized
>

What NTP server are you using? Network latency might cause the clocks 
not to be synchronised.

Wido

> Stefan
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Re: clock syncronisation

[Andrey Korolyov]

On Thu, Nov 8, 2012 at 4:00 PM, Wido den Hollander <wido@widodh.nl> wrote:
>
>
> On 08-11-12 10:04, Stefan Priebe - Profihost AG wrote:
>>
>> Hello list,
>>
>> is there any prefered way to use clock syncronisation?
>>
>> I've tried running openntpd and ntpd on all servers but i'm still getting:
>> 2012-11-08 09:55:38.255928 mon.0 [WRN] message from mon.2 was stamped
>> 0.063136s in the future, clocks not synchronized
>> 2012-11-08 09:55:39.328639 mon.0 [WRN] message from mon.2 was stamped
>> 0.063285s in the future, clocks not synchronized
>> 2012-11-08 09:55:39.328833 mon.0 [WRN] message from mon.2 was stamped
>> 0.063301s in the future, clocks not synchronized
>> 2012-11-08 09:55:40.819975 mon.0 [WRN] message from mon.2 was stamped
>> 0.063360s in the future, clocks not synchronized
>>
>
> What NTP server are you using? Network latency might cause the clocks not to
> be synchronised.
>

There is no real reason to worry about, quorum may suffer only large
desync delays as some seconds or more. If you have unsynchronized
clocks on mon hodes with such big delays, requests which have issued
from cli, e.g. creating new connection may wait as long as delay
itself, depend of clock value of selected monitor node.

Clock drift caused mostly by heavy load, but of course playing with
clocksources may have some effect(since most systems already use HPET
timer, there is only one way, to sync with ntp server as frequent as
you want to prevent drift).


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>
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Re: clock syncronisation

[Stefan Priebe - Profihost AG]

Am 08.11.2012 13:00, schrieb Wido den Hollander:
>
>
> On 08-11-12 10:04, Stefan Priebe - Profihost AG wrote:
>> Hello list,
>>
>> is there any prefered way to use clock syncronisation?
>>
>> I've tried running openntpd and ntpd on all servers but i'm still
>> getting:
>> 2012-11-08 09:55:38.255928 mon.0 [WRN] message from mon.2 was stamped
>> 0.063136s in the future, clocks not synchronized
>> 2012-11-08 09:55:39.328639 mon.0 [WRN] message from mon.2 was stamped
>> 0.063285s in the future, clocks not synchronized
>> 2012-11-08 09:55:39.328833 mon.0 [WRN] message from mon.2 was stamped
>> 0.063301s in the future, clocks not synchronized
>> 2012-11-08 09:55:40.819975 mon.0 [WRN] message from mon.2 was stamped
>> 0.063360s in the future, clocks not synchronized
>>
>
> What NTP server are you using? Network latency might cause the clocks
> not to be synchronised.

pool.ntp.org

But i've now switched to debian chrony instead of ntp and that seems to 
work fine.

Haven't seen any messages again.

Stefan