| Re: [chrony-users] Re: chrony losing sync with timeserver and never recovers |
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I am certainly confused by the log. The GPS and the
PPS have never delivered a valid ntp to chrony. What happened 463 days ago?
When was this system started?
Or have you edited these responses, not showing us the complete picture?
Ie, are there other servers which are being polled? It may be that if there is
no response from a server for N poll periods, chrony gives up and stops
polling. I no longer know chrony well enough to say that this is what happens
or not.
On Thu, 19 Oct 2017, Brendan Simon (eTRIX) wrote:
Hi chrony-users,
Anyone know why chrony would stop polling time servers? maxpoll is supposed
to be 1024 (17 minutes) max, but I my system polls initially and then seems
to stop polling servers completely. The example below shows 463 days with
no response from 2 servers.
Chrony 1.30 on Debian 8 (Jessie)
Thanks, Brendan.
____________________________________________________________________________
On 17/10/17 2:24 pm, Brendan Simon wrote:
I have a number embedded systems that are located in remote
areas that need to be up 24/7 for logging of data via a 3G
internet connection. The systems are ARM based and running
Debian 8 (Jessie) with chrony installed as the ntp client.
The systems sync with 2 ntp servers (`tic.ntp.telstra.net` and
`toc.ntp.telstra.net`) on boot. I know this because (a) there
is no RTC on the system, and (b) the application does not start
until the system date is > 2015 (i.e. not the startup of default
1970).
For some reason chrony loses sync with the servers and never
recovers. I have system times that are out by minutes !!
# chronyc sources
210 Number of sources = 4
MS Name/IP address Stratum Poll Reach LastRx
Last sample
===========================================================================
====
#? GPS 0 4 0
10y +0ns[ +0ns] +/- 0ns
#? PPS 0 4 0
10y +0ns[ +0ns] +/- 0ns
^? tic.ntp.telstra.net 2 10 0
463d -14ms[ -15ms] +/- 44ms
^? toc.ntp.telstra.net 2 10 0
463d -23ms[ -24ms] +/- 79ms
As can be seen, the servers have a state of '?' and haven't
recieved data in 463 days !! yet I can ping them ok, and if I
restart chrony all is good again.
The 3G modem can have problems and are reset (powered down and
up) whenever internet connectivity is lost (detected by pings
not responding). And 3G connectivity is not the most reliable.
The interesting parts of the config are:
It would actually be more helpful if you gave us all the information. You do
not know what is happening, so how can you be sure that these are the
only "interesting" commands in your chrony.conf?
server tic.ntp.telstra.net iburst
server toc.ntp.telstra.net iburst
makestep 1000 -1
initstepslew 30 0.au.pool.ntp.org 1.au.pool.ntp.org
2.au.pool.ntp.org 3.au.pool.ntp.org
What causes chrony to not retry servers?
Is there a config setting I need to always try these servers?
I notice the `online` and `offline` settings. Do I need to
explicitly tag servers as `online`? I presume that's the
default.
Do I need to explicitly tag the servers as `offline` before
powering the modem up and down? I thought leaving them online
would be ok. The only downside is it may take a little longer
to get the time back in sync, right?
But they can only get back in sync if chrony is talking to the
servers.
It might help to tag them as online when the 3g comes back up.
Thanks,
Brendan.