| Re: [chrony-users] Fallback clock on event "Can't synchronise: no reachable sources" |
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Thanks for your help!
On 18.02.2014 20:48, Bill Unruh wrote:
On Tue, 18 Feb 2014, Ulrich Schwesinger wrote:
The system waits for a poll interval before polling. If you poll
interval is 10, that is 20 min. (approx)
minpoll 5
maxpoll 7
There seem to be times when maxpoll ~ 2 mins is exceeded, no?
Hi,
I finally could get the tracking logs from the computer with one of
the events in there, where the server is not reachable. Would be
great if someone could help me interpret them. What I find strange is
that there are large time intervals without an entry in the
tracking.log file ... what does that mean? Is there something that
looks suspicious?
What looks suspicious is your source 192.168.0.30. What is that? Is
it going
mad.
I have a system with a write protected system partition and an NTP
server running within a local network.
192.168.0.30 is the LAN NTP server address, there is no WAN connection
or GPS time within the system.
Also your PPS/GPS? source seems to be having trouble getting locks.
I know on one of my Sure GPS devices the antenna was crap, and would
flake out
for long periods of time, giving no signal. Is something similar
happening to
you?
No, as I said no GPS receiver involved. But we recently experienced an
overload of one of the threads of the NTP server. Unfortunately the NTP
server is managed by another team of a project of mine, and before
escalating this I wanted to make sure that my client side is not the one
having the issue.
The measurements logs and the refclock log would also have been helpful
Do you mean the NTP servers log files with refclock log? It would be
quite some trouble for me to get these (please do not ask why, the
reason is annoying).
measurement.log:
2014-02-17 11:09:38 192.168.0.30 N 13 1111 111 1111 6 6 0.86
8.000e-06 7.020e-04 1.017e-06 0.000e+00 1.111e-02
2014-02-17 11:10:42 192.168.0.30 N 13 1111 111 1111 7 6 0.14
1.400e-05 6.860e-04 1.007e-06 0.000e+00 1.112e-02
========================================================================================================================
Date (UTC) Time IP Address L St 1234 abc 5678 LP RP Score
Offset Peer del. Peer disp. Root del. Root disp.
========================================================================================================================
2014-02-17 11:19:02 192.168.0.30 N 13 1111 111 1111 5 7 0.00
-4.645e-01 7.341e-04 2.552e-06 0.000e+00 1.094e-02
2014-02-17 11:19:34 192.168.0.30 N 13 1111 111 1111 5 5 0.00
-4.646e-01 7.441e-04 2.590e-06 0.000e+00 1.141e-02
2014-02-17 11:20:06 192.168.0.30 N 13 1111 111 1111 5 5 0.00
-4.646e-01 6.991e-04 2.500e-06 0.000e+00 1.094e-02
2014-02-17 11:20:38 192.168.0.30 N 13 1111 111 1111 5 5 0.00
3.324e-02 6.410e-04 1.669e-05 0.000e+00 1.143e-02
2014-02-17 11:21:10 192.168.0.30 N 13 1111 111 1111 5 5 0.00
3.678e-03 7.381e-04 3.567e-06 0.000e+00 1.096e-02
========================================================================================================================
Date (UTC) Time IP Address L St 1234 abc 5678 LP RP Score
Offset Peer del. Peer disp. Root del. Root disp.
========================================================================================================================
2014-02-17 11:22:30 192.168.0.30 N 13 1111 111 1111 5 5 0.00
-2.600e-05 6.291e-04 1.072e-01 0.000e+00 1.117e-02
2014-02-17 11:22:32 192.168.0.30 N 13 1111 111 1111 5 5 0.00
-1.513e-02 6.041e-04 8.038e-02 0.000e+00 1.120e-02
2014-02-17 11:22:34 192.168.0.30 N 13 1111 111 1111 5 5 0.00
8.534e-03 7.081e-04 4.522e-02 0.000e+00 1.123e-02
2014-02-17 11:22:36 192.168.0.30 N 13 1111 111 1111 5 5 0.00
1.322e-02 7.441e-04 2.412e-02 0.000e+00 1.126e-02
2014-02-17 11:23:09 192.168.0.30 N 13 1111 111 1111 5 5 0.00
1.038e-02 8.971e-04 4.354e-06 0.000e+00 1.176e-02
2014-02-17 11:23:41 192.168.0.30 N 13 1111 111 1111 5 5 0.00
-1.700e-04 7.021e-04 2.847e-06 0.000e+00 1.128e-02
2014-02-17 11:24:13 192.168.0.30 N 13 1111 111 1111 5 5 0.03
-2.900e-05 7.340e-04 1.380e-06 0.000e+00 1.176e-02
2014-02-17 11:24:46 192.168.0.30 N 13 1111 111 1111 5 5 0.08
-5.100e-05 7.330e-04 1.592e-06 0.000e+00 1.129e-02
2014-02-17 11:25:18 192.168.0.30 N 13 1111 111 1111 5 5 0.17
-2.300e-05 7.040e-04 1.670e-06 0.000e+00 1.178e-02
2014-02-17 11:25:50 192.168.0.30 N 13 1111 111 1111 5 5 0.28
-8.500e-05 6.250e-04 1.436e-06 0.000e+00 1.129e-02
========================================================================================================================
Date (UTC) Time IP Address L St 1234 abc 5678 LP RP Score
Offset Peer del. Peer disp. Root del. Root disp.
========================================================================================================================
2014-02-17 12:42:30 192.168.0.30 N 13 1111 111 1111 5 7 0.00
-4.234e-01 6.650e-04 2.370e-06 0.000e+00 7.948e+00
2014-02-17 12:43:02 192.168.0.30 N 13 1111 111 1111 5 5 0.00
-4.285e-01 7.021e-04 2.476e-06 0.000e+00 3.948e+00
2014-02-17 12:43:35 192.168.0.30 N 13 1111 111 1111 5 5 0.00
-4.336e-01 6.371e-04 2.342e-06 0.000e+00 3.948e+00
Thanks a lot, I appreciate the help!
Ulrich
tracking.log:
2014-02-17 11:09:38 192.168.0.30 14 -188.815 0.128
-2.652e-06 N 1 1.041e-05 -1.000e-06
2014-02-17 11:10:42 192.168.0.30 14 -188.825 0.105
-5.002e-06 N 1 9.495e-06 1.000e-06
==================================================================================================
Date (UTC) Time IP Address St Freq ppm Skew ppm Offset L
Co Offset sd Rem. corr.
==================================================================================================
2014-02-17 11:14:47 0.0.0.0 0 -188.825 0.105
0.000e+00 ? 0 0.000e+00 0.000e+00
2014-02-17 11:20:06 192.168.0.30 14 -188.825 0.105
4.646e-01 N 1 8.165e-06 0.000e+00
2014-02-17 11:20:38 192.168.0.30 14 -188.825 0.105
-2.960e-02 N 1 7.342e-03 -4.700e-05
2014-02-17 11:21:10 192.168.0.30 14 -188.825 0.105
-1.061e-02 N 1 8.911e-03 3.000e-06
==================================================================================================
Date (UTC) Time IP Address St Freq ppm Skew ppm Offset L
Co Offset sd Rem. corr.
==================================================================================================
2014-02-17 11:22:27 0.0.0.0 0 -188.825 0.105
0.000e+00 ? 0 0.000e+00 0.000e+00
2014-02-17 11:22:34 192.168.0.30 14 -188.825 0.105
-7.041e-03 N 1 7.408e-03 -1.356e-01
2014-02-17 11:22:36 192.168.0.30 14 -188.825 0.105
-1.281e-02 N 1 3.420e-03 -7.234e-02
2014-02-17 11:23:09 192.168.0.30 14 -188.825 0.105
-1.038e-02 N 1 1.155e-04 -4.000e-06
2014-02-17 11:23:41 192.168.0.30 14 -188.825 0.118
1.650e-04 N 1 1.582e-04 1.000e-06
2014-02-17 11:24:13 192.168.0.30 14 -188.825 0.141
4.837e-05 N 1 1.365e-04 -2.000e-06
2014-02-17 11:24:46 192.168.0.30 14 -188.824 0.191
6.054e-05 N 1 1.155e-04 -1.800e-05
2014-02-17 11:25:18 192.168.0.30 14 -188.820 0.296
4.109e-05 N 1 9.687e-05 -1.000e-05
2014-02-17 11:25:50 192.168.0.30 14 -188.792 0.584
7.567e-05 N 1 7.849e-05 -6.000e-06
==================================================================================================
Date (UTC) Time IP Address St Freq ppm Skew ppm Offset L
Co Offset sd Rem. corr.
==================================================================================================
2014-02-17 11:27:07 0.0.0.0 0 -188.825 0.105
0.000e+00 ? 0 0.000e+00 0.000e+00
2014-02-17 12:43:35 192.168.0.30 14 -188.821 0.912
4.336e-01 N 1 1.704e-06 0.000e+00
2014-02-17 12:44:07 192.168.0.30 14 -188.821 0.912
-7.320e-04 N 1 8.288e-03 -4.400e-05
2014-02-17 12:44:40 192.168.0.30 14 -188.821 0.912
-7.830e-03 N 1 9.486e-03 5.310e-04
2014-02-17 12:45:12 192.168.0.30 14 -188.821 0.912
-4.389e-03 N 1 9.422e-03 1.060e-03
2014-02-17 12:45:45 192.168.0.30 14 -188.821 0.912
6.342e-04 N 1 8.040e-03 6.480e-04
2014-02-17 12:46:17 192.168.0.30 14 -188.821 0.912
3.129e-03 N 1 6.983e-03 1.300e-05
statistics.log:
2014-02-17 11:09:38 192.168.0.30 1.751e-05 -2.652e-06 1.041e-05
-4.848e-09 1.200e-07 4.5e-02 15 0 9
2014-02-17 11:10:42 192.168.0.30 1.708e-05 -5.002e-06 9.495e-06
-1.166e-08 9.607e-08 9.1e-02 16 0 9
==============================================================================================================
Date (UTC) Time IP Address Std dev'n Est offset Offset sd
Diff freq Est skew Stress Ns Bs Nr
==============================================================================================================
2014-02-17 11:20:06 192.168.0.30 1.246e-05 4.646e-01 8.165e-06
2.219e-06 1.972e-04 1.1e-03 3 0 3
2014-02-17 11:20:38 192.168.0.30 1.218e-02 -2.960e-02 7.342e-03
-4.316e-04 6.069e-03 2.2e+00 4 0 3
2014-02-17 11:21:10 192.168.0.30 1.131e-02 -1.061e-02 8.911e-03
-3.883e-04 1.876e-03 7.1e-03 5 0 4
==============================================================================================================
Date (UTC) Time IP Address Std dev'n Est offset Offset sd
Diff freq Est skew Stress Ns Bs Nr
==============================================================================================================
2014-02-17 11:22:34 192.168.0.30 1.128e-02 -7.035e-03 7.408e-03
-4.449e-03 3.047e+00 2.2e+00 3 0 3
2014-02-17 11:22:36 192.168.0.30 5.950e-03 -1.281e-02 3.420e-03
-5.375e-03 5.774e-02 3.0e-04 4 0 3
2014-02-17 11:23:09 192.168.0.30 2.581e-04 -1.038e-02 1.155e-04
-4.700e-04 2.011e-03 8.5e-02 5 0 3
2014-02-17 11:23:41 192.168.0.30 3.054e-04 1.650e-04 1.582e-04
4.645e-06 6.898e-05 2.4e-01 6 0 3
2014-02-17 11:24:13 192.168.0.30 2.378e-04 4.837e-05 1.365e-04
2.609e-06 2.497e-05 3.0e-02 7 0 4
2014-02-17 11:24:46 192.168.0.30 1.989e-04 6.054e-05 1.155e-04
2.262e-06 1.223e-05 1.4e-02 8 0 4
2014-02-17 11:25:18 192.168.0.30 1.728e-04 4.109e-05 9.687e-05
1.919e-06 7.081e-06 2.8e-02 9 0 4
2014-02-17 11:25:50 192.168.0.30 1.505e-04 7.567e-05 7.849e-05
2.041e-06 4.414e-06 1.8e-02 10 0 5
==============================================================================================================
Date (UTC) Time IP Address Std dev'n Est offset Offset sd
Diff freq Est skew Stress Ns Bs Nr
==============================================================================================================
2014-02-17 12:43:35 192.168.0.30 2.542e-06 4.336e-01 1.704e-06
1.581e-04 3.583e-05 7.9e-02 3 0 3
2014-02-17 12:44:07 192.168.0.30 8.349e-03 -7.320e-04 8.288e-03
7.286e-05 4.410e-03 2.4e+00 4 0 3
2014-02-17 12:44:40 192.168.0.30 9.411e-03 -7.830e-03 9.486e-03
-3.330e-05 1.436e-03 2.4e-02 5 0 3
2014-02-17 12:45:12 192.168.0.30 9.003e-03 -4.389e-03 9.422e-03
-5.436e-05 7.140e-04 1.5e-02 6 0 3
2014-02-17 12:45:45 192.168.0.30 8.527e-03 6.342e-04 8.040e-03
-3.774e-05 3.979e-04 2.3e-02 7 0 4
2014-02-17 12:46:17 192.168.0.30 8.356e-03 3.129e-03 6.983e-03
-1.324e-05 2.566e-04 6.2e-02 8 0 4
On 07.02.2014 15:37, Miroslav Lichvar wrote:
On Fri, Feb 07, 2014 at 02:10:32PM +0100, Ulrich Schwesinger wrote:
> I have a system with a write protected system partition and an NTP
> server running within a local network. Sporadically, chrony reports
> the above mentioned error.
> The error persists maybe within a time range of 20-30 seconds.
> Within that time interval, the system time seems to diverge/drift by
> a couple of 10 milliseconds, which seems unreasonable large for me.
How did you measure the error in that period?
> (a) What is chrony exactly doing upon the event "Can't synchronise:
> no reachable sources". It does not seem to keep the current system
> time. Is it falling back on hardware clock maybe?
No, nothing with RTC. It should keep the system clock as it was set on
the last update unless chronyd is configured with the fallbackdrift
option.
> (b) Or might something be wrong with the drift estimate, causing
> this large divergence during the short time interval
Did it switch to another source before the "no reachable sources"
message? If there are multiple sources and the worst source becomes
unreachable as last, the clock will be set by the measurement from the
worst source, possibly introducing a large time or frequency error.
> (c) Are there some files I could look at the trace back what's
> happening within these time intervals?
The tracking log would be very helpful here. You can enable logging
in chrony.conf like this:
logdir /var/log/chrony
log measurements statistics tracking
I did not realise that you were using a refclock. Also log the refclock
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